PUMA publications for /user/b_schwederski/Grouphttps://puma.ub.uni-stuttgart.de/user/b_schwederski/GroupPUMA RSS feed for /user/b_schwederski/Group2024-03-29T08:25:20+01:00Charge and electron transfer from metal-to-carbon bonds of Main Group organometallics MRn (M = Al, Ga, Zn) to aromatic N-heterocycles: Colored precursor compounds and radical complex formationhttps://puma.ub.uni-stuttgart.de/bibtex/2d9ee0f23d6424807ea65c66cfa081e4f/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group aluminum bond carbon charge gallium metal organometallic organometallic;Main organometallic;heterocycle reaction transfer zinc <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Steffen Hasenzahl" itemprop="url" href="/person/1622b62cb6c03a189b81e752e83a7e73d/author/0"><span itemprop="name">S. Hasenzahl</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Kaim" itemprop="url" href="/person/1622b62cb6c03a189b81e752e83a7e73d/author/1"><span itemprop="name">W. Kaim</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Thomas. Stahl" itemprop="url" href="/person/1622b62cb6c03a189b81e752e83a7e73d/author/2"><span itemprop="name">T. Stahl</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Inorganica Chimica Acta</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">225 </span></span>(<span itemprop="issueNumber">1-2</span>):
<span itemprop="pagination">23--34</span></em> </span>(<em><span>1994<meta content="1994" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Inorganica Chimica Acta1-223--34Charge and electron transfer from metal-to-carbon bonds of Main Group organometallics MRn (M = Al, Ga, Zn) to aromatic N-heterocycles: Colored precursor compounds and radical complex formation2251994Group aluminum bond carbon charge gallium metal organometallic organometallic;Main organometallic;heterocycle reaction transfer zinc The coordinatively unsatd. compds. AlR3, GaR3 and ZnR2, R = iso-Pr, were reacted with linearly bridging pyrazine, tetramethylpyrazine or 4,4'-bipyridine ligands and with potentially chelating 2,2'-bipyridine. The primary reaction products are diamagnetic dinuclear complexes (bis-adducts) which are characterized by intense long-wavelength ligand-to-ligand charge transfer (LLCT) transitions \textgreek{s}(M-R)$\rightarrow$ \textgreek{p}*(L) and which may yield radical complexes after loss of R.bul.. The latter reaction is assumed to have a strong single electron transfer (SET) component. An isolable Al(II) species (bpy)Al[CH(SiMe3)2]2 has been characterized unambiguously by ESR, UV-Vis and cyclic voltammetry as an Al(III) complex of the bpy radical anion. Irradn. into the fairly intense LLCT absorption bands (\textgreek{e} {\textgreater} 3000 M-1 cm-1) of the dinuclear complexes between pyrazine and AliPr3 or GaiPr3 resulted in bleaching and formation of a mixt. of non-arom. products. Attempts are made to correlate charge transfer properties and radical formation with the geometrical and electronic structures of the precursor complexes. [on SciFinder(R)]Coordinative aspects of single electron exchange between Main group or transition metal compounds and unsaturated organic substrateshttps://puma.ub.uni-stuttgart.de/bibtex/2402feca8173d53ccc7c4b75f3c82bb42/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Main electron exchange exchange;transition group metal organo review review;review single <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/1fe4f84ef3aa275e045a613caca1701ed/author/0"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Studies in Physical and Theoretical Chemistry</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">78 </span></span>(<span itemprop="issueNumber">Electron Proton Transfer Chem. Biol</span>):
<span itemprop="pagination">45--69</span></em> </span>(<em><span>1992<meta content="1992" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Studies in Physical and Theoretical ChemistryElectron Proton Transfer Chem. Biol45--69Coordinative aspects of single electron exchange between Main group or transition metal compounds and unsaturated organic substrates781992Main electron exchange exchange;transition group metal organo review review;review single A review with {\textgreater}66 refs. Several examples are presented for inner sphere and outer sphere electron transfer in the reactions between electron rich organometallic main group or transition element compds. and electron deficient unsatd. substrates. Emphasis is placed on various steric and electronic aspects of (multiple) coordination between metal centers and the substrate as a requirement of consequence of intra- and intermol. single electron exchange. The examples include thermal and photoinduced electron transfer processes which result in various new stable dia- and paramagnetic follow-up products. [on SciFinder(R)]Singlet Diradical Complexes of Chromium, Molybdenum, and Tungsten with Azo Anion Radical Ligands from M(CO)6 Precursorshttps://puma.ub.uni-stuttgart.de/bibtex/26c562fff7aafd3326ae925336280fe71/b_schwederskib_schwederski2019-07-15T13:41:23+02:006 Group arylamidophenylazopyridine crystal diradical diradical;Group diradical;electronic electrochem metal prepn redox singlet structure <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Anasuya Sanyal" itemprop="url" href="/person/1412e0b435c810a4b3f4b91984d70c292/author/0"><span itemprop="name">A. Sanyal</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Sudipta Chatterjee" itemprop="url" href="/person/1412e0b435c810a4b3f4b91984d70c292/author/1"><span itemprop="name">S. Chatterjee</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Alfonso Castineiras" itemprop="url" href="/person/1412e0b435c810a4b3f4b91984d70c292/author/2"><span itemprop="name">A. Castineiras</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Biprajit Sarkar" itemprop="url" href="/person/1412e0b435c810a4b3f4b91984d70c292/author/3"><span itemprop="name">B. Sarkar</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Priti Singh" itemprop="url" href="/person/1412e0b435c810a4b3f4b91984d70c292/author/4"><span itemprop="name">P. Singh</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Jan Fiedler" itemprop="url" href="/person/1412e0b435c810a4b3f4b91984d70c292/author/5"><span itemprop="name">J. Fiedler</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Stanislav Zalis" itemprop="url" href="/person/1412e0b435c810a4b3f4b91984d70c292/author/6"><span itemprop="name">S. Zalis</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Kaim" itemprop="url" href="/person/1412e0b435c810a4b3f4b91984d70c292/author/7"><span itemprop="name">W. Kaim</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Sreebrata. Goswami" itemprop="url" href="/person/1412e0b435c810a4b3f4b91984d70c292/author/8"><span itemprop="name">S. Goswami</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Inorganic Chemistry</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">46 </span></span>(<span itemprop="issueNumber">21</span>):
<span itemprop="pagination">8584--8593</span></em> </span>(<em><span>2007<meta content="2007" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Inorganic Chemistry218584--8593Singlet Diradical Complexes of Chromium, Molybdenum, and Tungsten with Azo Anion Radical Ligands from M(CO)6 Precursors4620076 Group arylamidophenylazopyridine crystal diradical diradical;Group diradical;electronic electrochem metal prepn redox singlet structure The homoleptic diamagnetic complexes M(mer-L)2, M = Cr, Mo, W (1a,b, 2a,b, and 4a,b), were obtained by reacting the hexacarbonyls M(CO)6 with the tridentate ligands 2-[(2-N-arylamino)phenylazo]pyridine (HL = NH4C5N:NC6H4N(H)C6H4(H) (HLa) or NH4C5N:NC6H4N(H)C6H4Me (HLb)) in refluxing n-octane. In the case of M = Mo, dinuclear [Mo(L)(pap)]2(\textgreek{m}-O) (3a,b) (pap = 2-(phenylazo)pyridine), were obtained as second products in moist solvent. X-ray diffraction anal. for Cr(Lb)2 (1b), Mo(La)2 (2a), and W(La)2 (4a) reveals considerably distorted octahedral structures with trans-positioned azo-N atoms and cis-positioned 2-pyridyl-N and anilido N atoms. Whereas the Nazo-M-Nazo angle is larger than 170°, the other two trans angles are smaller, at $\sim$155° (M = Cr, 1b) or 146° (M = Mo, W; 2a, 4a), due to the overarching bite of the mer-tridentate ligands. The bonds from M to the neutral 2-pyridyl-N atoms are distinctly longer by {\textgreater}0.08 {\AA} than those to the anilido or azo N atoms, reflecting neg. charge on the latter. The N-N bond distances vary between 1.339(2) {\AA} for 1b and 1.373(3) {\AA} for 4a, clearly indicating the azo radical anion oxidn. state. Considering the addnl. neg. charge on anilido-N, the mononuclear complexes are thus formulated as MIV(L.bul.2-)2. The diamagnetism of the complexes as shown by magnetic susceptibility and 1H NMR expts. is believed to result from spin-spin coupling between the trans-positioned azo radical functions, resulting in a singlet diradical situation. The exptl. structures are well reproduced by d. functional theory calcns., which also support the overall electronic structure indicated. The dinuclear 3a with N-N distances of 1.348(10) {\AA} for La and 1.340(9) {\AA} for pap is also formulated as an azo anion radical-contg. Mo(IV) species, i.e., [MoIV(L.bul.2-)(pap.bul.-)]2(\textgreek{m}-O). All compds. can be reversibly reduced; the Cr complexes 1a,b are also reversibly oxidized in two steps. ESR spectroscopy indicates metal-centered spin for 1a+ and 1a- and g $\approx$ 2 signals for 2a-, 3a+, 3a-, and 4a-. Spectroelectrochem. in the UV-visible-NIR region showed small changes for the redn. of 2a, 3a, and 4a but extensive spectral changes for the redn. and oxidn. of 1a. [on SciFinder(R)]Interaction of frontier orbitals of Group 15 and Group 16 methides with the frontier orbitals of benzenehttps://puma.ub.uni-stuttgart.de/bibtex/2dd247d6e4f6157daed586230a3310cbf/b_schwederskib_schwederski2019-07-15T13:41:23+02:0015 16 16;methide Group MO;MO VA VIA affinity electron methide methide;electron spectra transmission <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Judith C. Giordan" itemprop="url" href="/person/17ea5294591d4c545467db27eed86711c/author/0"><span itemprop="name">J. Giordan</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="John H. Moore" itemprop="url" href="/person/17ea5294591d4c545467db27eed86711c/author/1"><span itemprop="name">J. Moore</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="John A. Tossell" itemprop="url" href="/person/17ea5294591d4c545467db27eed86711c/author/2"><span itemprop="name">J. Tossell</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/17ea5294591d4c545467db27eed86711c/author/3"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Journal of the American Chemical Society</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">107 </span></span>(<span itemprop="issueNumber">20</span>):
<span itemprop="pagination">5600--5604</span></em> </span>(<em><span>1985<meta content="1985" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Journal of the American Chemical Society205600--5604Interaction of frontier orbitals of Group 15 and Group 16 methides with the frontier orbitals of benzene107198515 16 16;methide Group MO;MO VA VIA affinity electron methide methide;electron spectra transmission Electron-transmission spectroscopy was used to det. the energies of low-lying neg.-ion states of MenM (M = N, P, As, n = 3; M = O, S, n = 2) as well as p-(MenM)2C6H4 (M = N, As, n = 3; M = O, S, n = 2). Spectral peaks are obsd., corresponding to electron capture into benzene \textgreek{p}* orbitals perturbed by interactions with the substituents and into substituent \textgreek{s}* orbitals. N substituents give a substantial splitting and destabilization of the benzene LUMO (\textgreek{p}4,5*), while P and As substituents cause little splitting and a slight stabilization of this orbital. Virtual orbital eigenvalues from min.-basis-set SCF-MO calcns. on the monosubstituted benzenes show the same trends. Redn. in the p character of the substituent lone pair, redn. in the magnitude of interactions, and increased stabilization of the benzene LUMO's by mixing with the substituent \textgreek{s}* orbitals along the N $\rightarrow$ As series may all contribute to this trend. Similarly, O substituents give a substantial \textgreek{p}4*-\textgreek{p}5* splitting while S substituents give primarily an inductive stabilization of the \textgreek{p}4,5* orbitals. [on SciFinder(R)]Chemistry of C-Trimethylsilyl-Substituted Heterocarboranes. 28. Selective Alkylation and Reactivity of \dqCarbons Adjacent\dq and \dqCarbons Apart\dq Tetracarba-nido-dodecaborane(12) Derivatives toward Group 1 and Group 2 Metals. Synthetic, Spectroscopic, and Structural Investigations on Lithium-, Sodium-, Potassium-, Cesium-, and Magnesium-Complexed C4B8 Carboraneshttps://puma.ub.uni-stuttgart.de/bibtex/27710d451094991120cbf5e8998ea4d51/b_schwederskib_schwederski2019-07-15T13:41:23+02:00DFT Group IA alkylation;magnesacarborane calcn calcn;mol crystal geometry magnesacarborane;heterocarborane magnesium metal metalation metallacarborane optimized prepn structure substituted substituted;DFT trimethylsilyl <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Narayan S. Hosmane" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/0"><span itemprop="name">N. Hosmane</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Hongming Zhang" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/1"><span itemprop="name">H. Zhang</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="John A. Maguire" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/2"><span itemprop="name">J. Maguire</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Ying Wang" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/3"><span itemprop="name">Y. Wang</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Temesgen Demissie" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/4"><span itemprop="name">T. Demissie</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Thomas J. Colacot" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/5"><span itemprop="name">T. Colacot</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Maria B. Ezhova" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/6"><span itemprop="name">M. Ezhova</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Kai-Juan Lu" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/7"><span itemprop="name">K. Lu</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Dunming Zhu" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/8"><span itemprop="name">D. Zhu</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Thomas G. Gray" itemprop="url" href="/person/12377abb8cc8cc5b2f0aeb71f97076b36/author/9"><span itemprop="name">T. Gray</span></a></span></span> und 6 andere Autor(en). </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Organometallics</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">19 </span></span>(<span itemprop="issueNumber">4</span>):
<span itemprop="pagination">497--508</span></em> </span>(<em><span>2000<meta content="2000" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Organometallics4497--508Chemistry of C-Trimethylsilyl-Substituted Heterocarboranes. 28. Selective Alkylation and Reactivity of {\dq}Carbons Adjacent{\dq} and {\dq}Carbons Apart{\dq} Tetracarba-nido-dodecaborane(12) Derivatives toward Group 1 and Group 2 Metals. Synthetic, Spectroscopic, and Structural Investigations on Lithium-, Sodium-, Potassium-, Cesium-, and Magnesium-Complexed C4B8 Carboranes192000DFT Group IA alkylation;magnesacarborane calcn calcn;mol crystal geometry magnesacarborane;heterocarborane magnesium metal metalation metallacarborane optimized prepn structure substituted substituted;DFT trimethylsilyl The carbons apart tetracarbon carborane nido-2,6-(R)2-4,12-(SiMe3)2-2,4,6,12-C4B8H8 [R = SiMe3 (I), Bu (II)] and several of its B-alkylated derivs. react with Mg metal in THF solvent to produce magnesacarboranes [e.g., (THF)2Mg(SiMe3)4(B-Bu-t)B4B7H7 (V)] in yields ranging from 57{\%} to 74{\%}. The magnesacarboranes were characterized by chem. anal. and IR and 1H, 11B, and 13C NMR spectroscopy and by single-crystal x-ray diffraction. Two types of cages were found, one in (THF)2Mg(SiMe3)4(B-Me)C4B7H7 (IV) and the other in (L)2Mg(SiMe3)2(R)2(B-Y)C4B7H7 [L = THF, R = SiMe3, Y = t-Bu (V); L = THF, R = SiMe3, Y = H (VI); (L)2 = TMEDA, R = Bu, Y = H (XI)]. Both cages showed electron-precise C and B atoms, as well as electron-deficient fragments. Approx. d. functional ab initio MO calcns. showed that the dianionic C4B8 cage can exist in a no. of energy-equiv. isomeric forms that can be trapped by a metal ion such as Mg. The reactions of I with the Group IA metals followed a different course in which two distinct steps occurred. The 1st step formed the paramagnetic intermediates which, in a slower step, reacted with a 2nd equiv. of the metal to give the diamagnetic [(SiMe3)4C4B8H8]2-. For the lighter metals, this dianion picked up a proton to give [(THF)4M][(SiMe3)4C4B8H9] [M = Li (VIII), Na (IX), K (X)] in 35-54{\%} yield. In the case of Cs, no protonation occurred and the final product was a polymeric dicesiacarborane, [exo-Cs(TMEDA)-1-Cs-(SiMe3)4C4B8H8]n (VII), isolated in 41{\%} yield. All were characterized by chem. anal. and IR and 1H, 11B, and 13C NMR spectroscopy; VII and VIII were addnl. characterized by single-crystal x-ray diffraction studies. In VIII-X the Group IA metal was solvated by four THF mols. and was not involved in the cage, while in VII one Cs occupied an apical position above a C3B3 open face of one carborane and bonded to a B3 face of a neighboring carborane. The 2nd Cs, solvated by a TMEDA mol., occupies an exo-polyhedral position and was not part of the polymeric chain. One carbons adjacent magnesacarborane, exo-(\textgreek{m}-H)3Mg(THF)3(SiMe3)2(Me)2C4B8H8 (XII), was also synthesized, in 81{\%} yield, by the reaction of the metal with the (SiMe3)2(Me)2C4B8H8 precursor. Single-crystal x-ray diffraction studies showed the compd. to be composed of an exo-polyhedral [Mg(THF)3]2+ that is loosely bound to a [(SiMe3)2(Me)2C4B8H8]2- cage. The carborane is best described as an 10-vertex arachno-(SiMe3)2C2B8H8 cage that subtends an electron-precise MeC:CMe fragment. [on SciFinder(R)]2-Heteroatom-1,3-diazoles and quinoxaline as bridging p-acceptor ligands for Group VIB metal carbonyl fragments M(CO)5 (M = Cr, Mo, W). Synthesis, electrochemistry, absorption and emission spectroscopyhttps://puma.ub.uni-stuttgart.de/bibtex/2f4d1a9bb83f927f31ed652370f78e63e/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group VIB carbonyl chalcogenadiazole chalcogenadiazole;selenadiazole chromium complex complex;Group complex;oxadiazole complex;quinoxaline complex;redn complex;thiadiazole complex;tungsten potential quinoxaline;molybdenum tungsten <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Kaim" itemprop="url" href="/person/1a0e5ceb623890f399b7b52fdfe7371e9/author/0"><span itemprop="name">W. Kaim</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Stephan Kohlmann" itemprop="url" href="/person/1a0e5ceb623890f399b7b52fdfe7371e9/author/1"><span itemprop="name">S. Kohlmann</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Alistair J. Lees" itemprop="url" href="/person/1a0e5ceb623890f399b7b52fdfe7371e9/author/2"><span itemprop="name">A. Lees</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Mthembeni. Zulu" itemprop="url" href="/person/1a0e5ceb623890f399b7b52fdfe7371e9/author/3"><span itemprop="name">M. Zulu</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Zeitschrift fuer Anorganische und Allgemeine Chemie</span>, </em> </span>(<em><span>1989<meta content="1989" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Zeitschrift fuer Anorganische und Allgemeine Chemie97--1142-Heteroatom-1,3-diazoles and quinoxaline as bridging \textgreek{p}-acceptor ligands for Group VIB metal carbonyl fragments M(CO)5 (M = Cr, Mo, W). Synthesis, electrochemistry, absorption and emission spectroscopy5751989Group VIB carbonyl chalcogenadiazole chalcogenadiazole;selenadiazole chromium complex complex;Group complex;oxadiazole complex;quinoxaline complex;redn complex;thiadiazole complex;tungsten potential quinoxaline;molybdenum tungsten M(CO)5L (M = Cr, Mo, W; L = 2,1,3-benzoxadiazole (bod), 2,1,3-benzothiadiazole (btd), 2,1,3-benzoselenadiazole (bsd)), [M1(CO)5]2L1 (M1 = Cr, W; L1 = bod, btd, bsd, quinoxaline, 2,1,3-thiadiazole) were prepd. and characterized by cyclic voltammetry, UV-visible adsorption and emission spectroscopy. The complexes exhibit low-lying metal-to-ligand charge transfer (MLCT, d $\rightarrow$ \textgreek{p}*) transitions as evident from long wavelength absorptions and are easily reduced to yield persistent anion radicals. [W(CO)5]2L1 (L1 = btd, bsd) show weak near IR ({\textgreater}750 nm) emission from rather short-lived MLCT excited states. While quinoxaline and monocyclic 2,1,3-thiadiazole also form binuclear W(CO)5 complexes, the related 2-methyl-1,2,3-benzotriazole does not bind W(CO)5 fragments in the neutral state but only as the more basic anion radical as evident from ESR spectroscopy. [on SciFinder(R)]Paramagnetic main Group and transition metal complexes containing unsaturated nitrogen ligandshttps://puma.ub.uni-stuttgart.de/bibtex/2c3c002a97349095657b9182fd041c278/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group complex ligand main metal nitrogen paramagnetic review review;paramagnetic transition <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Kaim" itemprop="url" href="/person/14f4adab9c4241864caa5c6dcbe4fe453/author/0"><span itemprop="name">W. Kaim</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Barbara. Olbrich-Deussner" itemprop="url" href="/person/14f4adab9c4241864caa5c6dcbe4fe453/author/1"><span itemprop="name">B. Olbrich-Deussner</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Journal of Organometallic Chemistry Library</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">22 </span></span>(<span itemprop="issueNumber">Organomet. Radical Processes</span>):
<span itemprop="pagination">173--200</span></em> </span>(<em><span>1990<meta content="1990" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Journal of Organometallic Chemistry LibraryOrganomet. Radical Processes173--200Paramagnetic main Group and transition metal complexes containing unsaturated nitrogen ligands221990Group complex ligand main metal nitrogen paramagnetic review review;paramagnetic transition A review with 164 refs. [on SciFinder(R)]3,3'-Bipyridazine: The 'second-best' bidiazine ligand for metal carbonyl M(CO)4 fragments (M = chromium, molybdenum, tungsten)https://puma.ub.uni-stuttgart.de/bibtex/2a0d4754e323ee2654314c671a25866ed/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group VIB bipyridazine bipyridazine;UV carbonyl <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Sylvia Ernst" itemprop="url" href="/person/1aa400c38b2d878e625188dbcab47cfbf/author/0"><span itemprop="name">S. Ernst</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/1aa400c38b2d878e625188dbcab47cfbf/author/1"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Inorganica Chimica Acta</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">114 </span></span>(<span itemprop="issueNumber">2</span>):
<span itemprop="pagination">123--125</span></em> </span>(<em><span>1986<meta content="1986" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Inorganica Chimica Acta2123--1253,3'-Bipyridazine: The 'second-best' bidiazine ligand for metal carbonyl M(CO)4 fragments (M = chromium, molybdenum, tungsten)1141986Group VIB bipyridazine bipyridazine;UV carbonyl Owing to its relatively high basicity (pKa1 = 3.37), 3,3'-bipyridazine (L) yields M(CO)4L (M = Cr, Mo, W) which have both metal-to-ligand charge transfer absorption max. at longer wavelengths than corresponding 2,2'-bipyrimidine and 2,2'-bipyrazine compds. After 4,4'-bipyramidine, 3,3'-bipyridazine is the 2nd-best \textgreek{p} acceptor among the sym. bidiazines with \textgreek{a}-diamine structure. Redox potentials were detd. [on SciFinder(R)]Heterocubane cluster compounds (NEt4)Y:M(μ3-S)Re(CO)33(μ3-E) (M = W or Mo, Y = O or S, E = S or Se). Structures, spectroscopy, and electrochemistryhttps://puma.ub.uni-stuttgart.de/bibtex/2bf63a6fdb9108e06bac398d785826dc1/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group VIB chalcogen crystal heterocubane heterocubane;IR heterocubane;redox heterocubane;rhenium potential prepn;UV rhenium structure <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Fridmann Hornung" itemprop="url" href="/person/1c0144b52936af0cda691842d656e365f/author/0"><span itemprop="name">F. Hornung</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Matthias Wanner" itemprop="url" href="/person/1c0144b52936af0cda691842d656e365f/author/1"><span itemprop="name">M. Wanner</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Karl Wilhelm Klinkhammer" itemprop="url" href="/person/1c0144b52936af0cda691842d656e365f/author/2"><span itemprop="name">K. Klinkhammer</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Kaim" itemprop="url" href="/person/1c0144b52936af0cda691842d656e365f/author/3"><span itemprop="name">W. Kaim</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Jan. Fiedler" itemprop="url" href="/person/1c0144b52936af0cda691842d656e365f/author/4"><span itemprop="name">J. Fiedler</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Zeitschrift fuer Anorganische und Allgemeine Chemie</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">627 </span></span>(<span itemprop="issueNumber">10</span>):
<span itemprop="pagination">2430--2444</span></em> </span>(<em><span>2001<meta content="2001" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Zeitschrift fuer Anorganische und Allgemeine Chemie102430--2444Heterocubane cluster compounds (NEt4){Y:M[(μ3-S)Re(CO)3]3(μ3-E)} (M = W or Mo, Y = O or S, E = S or Se). Structures, spectroscopy, and electrochemistry6272001Group VIB chalcogen crystal heterocubane heterocubane;IR heterocubane;redox heterocubane;rhenium potential prepn;UV rhenium structure Thiometalates [MS4]2- (M = Mo, W) or [WOS3]2- react with Re(CO)5(O3SCF3) and Li2E (E = S or Se) to yield the following compds. which were structurally characterized: (NEt4){S:W[(μ3-S)Re(CO)3]3(μ3-S)}(NEt4) (I), (NEt4){O/S:W[(μ3-S)Re(CO)3](μ3-S)}(NEt4) (I/II), (mixed crystals), (NEt4){S:W[(μ3-S)Re(CO)3]3(μ3-Se)}(NEt4) (III) and (NEt4){S:Mo[(μ3-S)Re(CO)3]3(μ3-S)}(NEt4) (IV). The heterocubane anions I-IV contain electron-rich centers such as Re(I) or sulfide whereas Mo(VI) or W(VI) act as acceptor sites. Accordingly, the absorption spectra show long-wavelength metal-to-ligand charge transfer transitions, and cyclic voltammetry reveals a quasi-reversible redn. of the clusters. Although both 6-coordinate Re(I) and 4-coordinate metal(VI) centers are present in the clusters there is no evidence for significant metal-to-metal charge transfer interaction. [on SciFinder(R)]Four bridging bis chelate ligands with very low lying p* orbitals. MO perturbation calculations, electrochemistry, and spectroscopy of mononuclear and binuclear group 6 metal tetracarbonyl complexeshttps://puma.ub.uni-stuttgart.de/bibtex/232ee25b910134ec22e13a1b299291934/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group MO VIB azobipyridine bipyrimidine bischelant carbonyl;Group carbonyl;MO carbonyl;electronic carbonyl;energy electrochem electrochem;bipyrimidine electrochem;electrochem electrochem;pyridyltetrazine level pyridylpyrazine pyridyltetrazine;pyridylpyrazine transition <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Kaim" itemprop="url" href="/person/16939cad18951d07991ceb8002a8240c6/author/0"><span itemprop="name">W. Kaim</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Stephan. Kohlmann" itemprop="url" href="/person/16939cad18951d07991ceb8002a8240c6/author/1"><span itemprop="name">S. Kohlmann</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Inorganic Chemistry</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">26 </span></span>(<span itemprop="issueNumber">1</span>):
<span itemprop="pagination">68--77</span></em> </span>(<em><span>1987<meta content="1987" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Inorganic Chemistry168--77Four bridging bis chelate ligands with very low lying \textgreek{p}* orbitals. MO perturbation calculations, electrochemistry, and spectroscopy of mononuclear and binuclear group 6 metal tetracarbonyl complexes261987Group MO VIB azobipyridine bipyrimidine bischelant carbonyl;Group carbonyl;MO carbonyl;electronic carbonyl;energy electrochem electrochem;bipyrimidine electrochem;electrochem electrochem;pyridyltetrazine level pyridylpyrazine pyridyltetrazine;pyridylpyrazine transition Coordination characteristics of the 4 bridging, \textgreek{p}-delocalized bis chelate ligands 2,2'-bipyrimidine (bpym), 2,5-bis(2-pyridyl)pyrazine (bppz), 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine (bptz), and azo-2,2'-bipyridine (abpy) were evaluated with use of \textgreek{p} MO perturbation calcns. and were studied exptl. by example of mononuclear and binuclear complexes with the fragments M(CO)4 (M = Cr, Mo, W). The substantial stabilization of the \textgreek{p}* (LUMO) levels in the order bpym, bppz, bptz, abpy strongly facilitates redn. of the complexes and causes shifts of the intense metal-to-ligand charge-transfer (LMCT) absorption bands out into the near-IR region. Despite a notable activation barrier for the formation of binuclear abpy complexes with 6-coordinate metals, (abpy)[Mo(CO)4]2 was prepd. and it exhibits most remarkable spectral properties such as an intense yet rather narrow and solvent-insensitive MLCT absorption band at 11,000 cm-1, another detectable absorption max. {\textgreater}30,000 cm-1, a redn. potential close to that of the ref. electrode, SCE, and closely spaced yet well-resolved CO stretching frequencies in the IR spectrum. All these spectral results can be correlated to \textgreek{p} MO calcn. data, which strongly suggest the use of bptz and abpy for studies concerned with ligand-mediated electronic interactions between metal centers. A particular asset of binuclear abpy complexes is the unusually short metal-metal distance caused by their coordination-induced S-frame conformation. [on SciFinder(R)]Thermal and light induced electron transfer reactions of Main Group metal hydrides and organometallicshttps://puma.ub.uni-stuttgart.de/bibtex/2529101a4172189cb17f695b98d19fa6a/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group Main electron hydride induced light review;organometallic review;review transfer <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/1d0a47103745051ef54f2baa4aba17a17/author/0"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Topics in Current Chemistry</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">169 </span></span>(<span itemprop="issueNumber">Electron Transfer I</span>):
<span itemprop="pagination">231--251</span></em> </span>(<em><span>1994<meta content="1994" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Topics in Current ChemistryElectron Transfer I231--251Thermal and light induced electron transfer reactions of Main Group metal hydrides and organometallics1691994Group Main electron hydride induced light review;organometallic review;review transfer A review with {\textgreater}143 refs. [on SciFinder(R)]Chemical and electrochemical reduction of pentacarbonyl(4-cyanopyridine) complexes of chromium(0), molybdenum(0) and tungsten(0)https://puma.ub.uni-stuttgart.de/bibtex/25056e1fad6ccf8772eaa446088a4cf10/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group VIB carbonyl chem chromium complex;ESR complex;tungsten cyanopyridine cyanopyridine;molybdenum electrochem electroredn electroredn;cyanopyridine electroredn;redn pentacarbonyl redn redn;electroredn <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/1d86f453cd52b5ebeb4eac3a93ee78896/author/0"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Inorganic Chemistry</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">23 </span></span>(<span itemprop="issueNumber">4</span>):
<span itemprop="pagination">504--506</span></em> </span>(<em><span>1984<meta content="1984" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Inorganic Chemistry4504--506Chemical and electrochemical reduction of pentacarbonyl(4-cyanopyridine) complexes of chromium(0), molybdenum(0) and tungsten(0)231984Group VIB carbonyl chem chromium complex;ESR complex;tungsten cyanopyridine cyanopyridine;molybdenum electrochem electroredn electroredn;cyanopyridine electroredn;redn pentacarbonyl redn redn;electroredn The complexes [LM(CO)5] (L = 4-cyanopyridine and M = Cr, Mo, W) were reduced by K in THF and at a glassy C electrode in DMF. The resulting radical anion complexes [LM(CO)5]-. were also obtained from replacement reactions of the metal hexacarbonyls with the ligand radical anion L-. or via electron transfer from decacarbonyldimetalates to the free ligand L. The radical complexes were characterized by high resoln. ESR. The unpaired electron resides predominately in the heterocyclic ligand; only minor perturbations of spin distribution occur via the metal fragments. The results are related to the MLCT features in the electronic spectra of these complexes. [on SciFinder(R)]Heterocyclic radical anions as ligands: An unexpected coordination change in pentacarbonylmetal complexeshttps://puma.ub.uni-stuttgart.de/bibtex/210481207494b1ba280cd180c99a8061c/b_schwederskib_schwederski2019-07-15T13:41:23+02:00ESR VIB benzo benzochalcogenadiazole;oxadiazole carbonyl carbonyl;selenadiazole carbonyl;sulfadiazole group <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Kaim" itemprop="url" href="/person/1a128bb71df3a8eb5a649f9460f9bc689/author/0"><span itemprop="name">W. Kaim</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Volker. Kasack" itemprop="url" href="/person/1a128bb71df3a8eb5a649f9460f9bc689/author/1"><span itemprop="name">V. Kasack</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Angewandte Chemie</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">94 </span></span>(<span itemprop="issueNumber">9</span>):
<span itemprop="pagination">712--713</span></em> </span>(<em><span>1982<meta content="1982" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Angewandte Chemie9712--713Heterocyclic radical anions as ligands: An unexpected coordination change in pentacarbonylmetal complexes941982ESR VIB benzo benzochalcogenadiazole;oxadiazole carbonyl carbonyl;selenadiazole carbonyl;sulfadiazole group M(CO)6 (M = Cr, W, Mo) react in THF with the radical anion I to give {[(CO)5M]2L}-. (M = Cr, Mo; L = I; X = O, S, Se; M = W; X = O, S) and {(CO)5WL}-. (X = Se). In {[(CO)5W]L}-., L is coordinated to W through the Se atom. The complexes were detected by ESR spectra. [on SciFinder(R)]EPR Characteristics of the (NC)5M(NO)3- Ions (M = Fe, Ru, Os). Experimental and DFT Study Establishing NO.bul. as a Ligandhttps://puma.ub.uni-stuttgart.de/bibtex/2704ea00c19a09a11422b8a0e260199ab/b_schwederskib_schwederski2019-07-15T13:41:23+02:008 ESR ESR;osmium ESR;ruthenium Group complex complex;iron cyano nitrosyl prepn <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Matthias Wanner" itemprop="url" href="/person/1d9ad95bebcf24d1735c80352fb999e8d/author/0"><span itemprop="name">M. Wanner</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Thomas Scheiring" itemprop="url" href="/person/1d9ad95bebcf24d1735c80352fb999e8d/author/1"><span itemprop="name">T. Scheiring</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Kaim" itemprop="url" href="/person/1d9ad95bebcf24d1735c80352fb999e8d/author/2"><span itemprop="name">W. Kaim</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Leonardo D. Slep" itemprop="url" href="/person/1d9ad95bebcf24d1735c80352fb999e8d/author/3"><span itemprop="name">L. Slep</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Luis M. Baraldo" itemprop="url" href="/person/1d9ad95bebcf24d1735c80352fb999e8d/author/4"><span itemprop="name">L. Baraldo</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Jose A. Olabe" itemprop="url" href="/person/1d9ad95bebcf24d1735c80352fb999e8d/author/5"><span itemprop="name">J. Olabe</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Stanislav Zalis" itemprop="url" href="/person/1d9ad95bebcf24d1735c80352fb999e8d/author/6"><span itemprop="name">S. Zalis</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Evert Jan. Baerends" itemprop="url" href="/person/1d9ad95bebcf24d1735c80352fb999e8d/author/7"><span itemprop="name">E. Baerends</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Inorganic Chemistry</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">40 </span></span>(<span itemprop="issueNumber">22</span>):
<span itemprop="pagination">5704--5707</span></em> </span>(<em><span>2001<meta content="2001" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Inorganic Chemistry225704--5707EPR Characteristics of the [(NC)5M(NO)]3- Ions (M = Fe, Ru, Os). Experimental and DFT Study Establishing NO.bul. as a Ligand4020018 ESR ESR;osmium ESR;ruthenium Group complex complex;iron cyano nitrosyl prepn K2[(NC)5Ru(NO)] was prepd. from K4[Ru(CN)6] and KNO2 and converted to (NEt4)2[(NC)5Ru(NO)]. The g factor components of [(NC)5M(NO)]3- (M = Fe, Ru, Os) were calcd. by relativistic d. functional calcns., including spin-orbit coupling. The calcd. values are in good agreement with previous (M = Fe) and new exptl. results (M = Ru, Os). Spin-orbit coupling effects are particularly strong for the osmium system. Whereas MII-NO· is the most appropriate formulation describing the spin distribution, there is substantial contribution (ca. 25 {\%} ) from the metal to the singly occupied MO in each case. [on SciFinder(R)]Ambidentate ligand with high p-acceptor capacity: D6-metal complexes of 4,4'-bipyrimidinehttps://puma.ub.uni-stuttgart.de/bibtex/2dd46420ded7276f8b1fe5f6a1f5c2fbe/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group VIB bipyridine bipyrimidine bipyrimidine;bipyrimidine bipyrimidine;chromium bipyrimidine;tungsten carbonyl carbonyl;molybdenum carbonyl;redox electrochem metal ruthenium ruthenium;carbonyl transition <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Sylvia Ernst" itemprop="url" href="/person/1a7fdf3b06bd5b5af5d5653c78b31ab31/author/0"><span itemprop="name">S. Ernst</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/1a7fdf3b06bd5b5af5d5653c78b31ab31/author/1"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Angewandte Chemie</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">97 </span></span>(<span itemprop="issueNumber">5</span>):
<span itemprop="pagination">431--433</span></em> </span>(<em><span>1985<meta content="1985" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Angewandte Chemie5431--433Ambidentate ligand with high \textgreek{p}-acceptor capacity: D6-metal complexes of 4,4'-bipyrimidine971985Group VIB bipyridine bipyrimidine bipyrimidine;bipyrimidine bipyrimidine;chromium bipyrimidine;tungsten carbonyl carbonyl;molybdenum carbonyl;redox electrochem metal ruthenium ruthenium;carbonyl transition M(CO)5(THF) (M = Cr, Mo, W), Ru(bpy)2Cl2 (bpy = 2,2'-bipyridine), and RuCl2(DMSO)4 reacted with 4,4'-bipyrimidine (L) to give M(CO)4L, [Ru(bpy)2L](PF6)2, and [RuL3](PF6)2, resp. [W(CO)5]2L, that was prepd. from W(CO)5(THF) and L (2:1 ratio), under reflux was converted to W(CO)4L. The redox potentials are obtained for M(CO)4L, [Ru(bpy)2L](PF6)2, and [W(CO)5]2L. For [RuL3](PF6)2 the elec. potentials were obtained for the Ru3+/Ru2+, Ru2+/Ru+, Ru+/Ru0, and Ru0/Ru- couples. The complexes were characterized by IR, electronic, NMR, and ESR spectra. [on SciFinder(R)]Mono- and binuclear tri- and tetracarbonyl complexes of chromium(0), molybdenum(0), and tungsten(0) with the 2,2'-bipyrimidine radical anionhttps://puma.ub.uni-stuttgart.de/bibtex/2e66e3f6c255933e8a07cff4565c504df/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group VIB anion;molybdenum bipyrimidine carbonyl carbonyl;ESR radical substitution tributylphosphine <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/189d779412465b6d16be7335a534843e7/author/0"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Inorganic Chemistry</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">23 </span></span>(<span itemprop="issueNumber">21</span>):
<span itemprop="pagination">3365--3368</span></em> </span>(<em><span>1984<meta content="1984" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Inorganic Chemistry213365--3368Mono- and binuclear tri- and tetracarbonyl complexes of chromium(0), molybdenum(0), and tungsten(0) with the 2,2'-bipyrimidine radical anion231984Group VIB anion;molybdenum bipyrimidine carbonyl carbonyl;ESR radical substitution tributylphosphine [((CO)4M)x bpym]-. (x = 1, 2; M = Cr, Mo, W; bpym = 2,2'-bipyrimidine) were studied by high-resoln. ESR. The unpaired electron resides predominantly in the LUMO of the heterocycle; HMO-McLachlan calcns. were used to interpret the hyperfine coupling consts. [((CO)4Mo)2bpym]- underwent successive replacement of 2 axial CO groups by PBu3. A \textgreek{p}*/\textgreek{s}* hyperconjugation model accounted for the facile CO substitution and for the spin transfer to the peripheral 31P nuclei. An unexpected behavior was found for the g values of the complexes, which were generally lower than the g of the free ligand. This result points to a strong contribution from a low-lying electronically excited state to the radical ground state. [on SciFinder(R)]Coordination characteristics of four isomeric a-diimine ligands. p Molecular orbital perturbation calculations for the bidiazines and their correlation with the properties of group 6 metal carbonyl complexeshttps://puma.ub.uni-stuttgart.de/bibtex/24f6433f1ea46898fc234a4249fcfb849/b_schwederskib_schwederski2019-07-15T13:41:23+02:00Group VIB basicity bidiazine bidiazine;Group bidiazine;bipyrazine bidiazine;electron bidiazine;molybdenum bidiazine;redox bidiazine;tungsten carbonyl carbonyl;bipyridazine carbonyl;bipyrimidine carbonyl;chromium configuration potential <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Sylvia Ernst" itemprop="url" href="/person/13efa3bf4b2b2a9ad87713cc0b5dd3acf/author/0"><span itemprop="name">S. Ernst</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/13efa3bf4b2b2a9ad87713cc0b5dd3acf/author/1"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Journal of the American Chemical Society</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">108 </span></span>(<span itemprop="issueNumber">13</span>):
<span itemprop="pagination">3578--3586</span></em> </span>(<em><span>1986<meta content="1986" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Journal of the American Chemical Society133578--3586Coordination characteristics of four isomeric \textgreek{a}-diimine ligands. \textgreek{p} Molecular orbital perturbation calculations for the bidiazines and their correlation with the properties of group 6 metal carbonyl complexes1081986Group VIB basicity bidiazine bidiazine;Group bidiazine;bipyrazine bidiazine;electron bidiazine;molybdenum bidiazine;redox bidiazine;tungsten carbonyl carbonyl;bipyridazine carbonyl;bipyrimidine carbonyl;chromium configuration potential Energies and charge distributions of the lower unoccupied \textgreek{p} MO's were detd. for the isomeric bidiazine ligands 3,3'-bipyridazine (bpdz), 4,4'-bipyrimidine (bpm), 2,2'-bipyrazine (bpz), and 2,2'-bipyrimidine (bpym) as well as for 2,2'-bipyridine (bpy) by Gueckel MO perturbation calcns. In conjunction with exptl. pKa values, the calcn. results are related to the different stabilities, redox potentials, and various spectroscopic properties of Cr, Mo, and W tetracarbonyl complexes with these ligands. W(CO)5L (L = bpdz, bpm) were isolated as intermediates in the reactions between W(THF)(CO)5 and L.. Each of the 4 isomeric ligands exhibits very characteristic features, and the potential uses of the individual systems for different purposes in coordination chem. are discussed. Whereas bpdz is the strongest base in that series, thus compensating for a rather high-lying \textgreek{p}* level, the bpm complexes exhibit the strongest back-bonding interaction because of a very low-lying \textgreek{p}* level and sufficient ligand basicity. The bpz system is distinguished by acquiring high amts. of addnl. charge at both sets of N centers upon redn., and finally, the otherwise less outstanding bpym ligand is unique among the bidiazine isomers by forming binuclear bischelate complexes on 2nd coordination. [on SciFinder(R)]Structures and redox properties of metal complexes of the electron-deficient diphosphine chelate ligand R,R-quinoxPhttps://puma.ub.uni-stuttgart.de/bibtex/279cdb9a98a8b1b6241ccb64026794c8b/b_schwederskib_schwederski2019-07-15T13:41:23+02:00carbonyl complex complex;electrooxidn complex;electroredn complex;palladium crystal diphosphinoquinoxaline group platinum prepn structure structure;platinum structure;rhenium <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Atanu Kumar Das" itemprop="url" href="/person/19917f8ec8515ccfa875cb20958263a80/author/0"><span itemprop="name">A. Das</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Ece Bulak" itemprop="url" href="/person/19917f8ec8515ccfa875cb20958263a80/author/1"><span itemprop="name">E. Bulak</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Biprajit Sarkar" itemprop="url" href="/person/19917f8ec8515ccfa875cb20958263a80/author/2"><span itemprop="name">B. Sarkar</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Falk Lissner" itemprop="url" href="/person/19917f8ec8515ccfa875cb20958263a80/author/3"><span itemprop="name">F. Lissner</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Thomas Schleid" itemprop="url" href="/person/19917f8ec8515ccfa875cb20958263a80/author/4"><span itemprop="name">T. Schleid</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Mark Niemeyer" itemprop="url" href="/person/19917f8ec8515ccfa875cb20958263a80/author/5"><span itemprop="name">M. Niemeyer</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Jan Fiedler" itemprop="url" href="/person/19917f8ec8515ccfa875cb20958263a80/author/6"><span itemprop="name">J. Fiedler</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/19917f8ec8515ccfa875cb20958263a80/author/7"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Organometallics</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">27 </span></span>(<span itemprop="issueNumber">2</span>):
<span itemprop="pagination">218--223</span></em> </span>(<em><span>2008<meta content="2008" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Organometallics2218--223Structures and redox properties of metal complexes of the electron-deficient diphosphine chelate ligand R,R-quinoxP272008carbonyl complex complex;electrooxidn complex;electroredn complex;palladium crystal diphosphinoquinoxaline group platinum prepn structure structure;platinum structure;rhenium The air-stable chiral diphosphine chelate ligand R,R-qinoxP (L; 2,3-bis(tert-butylmethylphosphino)quinoxaline) as developed by Imamoto et al. (2005). L was used to obtain the crystallog. characterized complexes (L)PtCl2 (1), (L)PdCl2 (2), and (L)Re(CO)3Cl (3). Coordination occurs via the P donor atoms, as indicated by crystal structures and NMR studies; the quinoxaline N donors do not participate in any coordination to the metals. The stereochem. arrangements obsd. illustrate the enantioselectivity reported for catalysis involving complexes of L. Electron acceptance by the quinoxaline heterocycle is responsible not only for the improved stability of L toward air but also for rather facile redn. of the complexes to the persistent radical anions 1·-and 3·- In contrast, the redn. to 2·- proceeds irreversibly even at 243 K in the absence of excess chloride. EPR, UV-vis, and IR spectroelectrochem. was used, when possible, to establish the spin location in the quinoxaline \textgreek{p} system with rather small contributions from the metals or the P nuclei. [on SciFinder(R)]EPR study of electron transfer and group transfer in organoplatinum(II) and (IV) compoundshttps://puma.ub.uni-stuttgart.de/bibtex/20f40a77fe96947fad5e59587f36f3740/b_schwederskib_schwederski2019-07-15T13:41:23+02:004 anion;ESR chelate chelate;electron chelate;homolysis diazabutadiene diazabutadiene;methyl diazabutadiene;platinum electrochem group mesityl methyl organoplatinum photochem platinum radical radical;photohomolysis redn transfer <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Axel Klein" itemprop="url" href="/person/156b06388224c0dc3784900a4204d16c5/author/0"><span itemprop="name">A. Klein</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Steffen Hasenzahl" itemprop="url" href="/person/156b06388224c0dc3784900a4204d16c5/author/1"><span itemprop="name">S. Hasenzahl</span></a></span>, </span> und <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/156b06388224c0dc3784900a4204d16c5/author/2"><span itemprop="name">W. Kaim</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry</span>, </em> </span>(<em><span>1997<meta content="1997" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry122573--2577EPR study of electron transfer and group transfer in organoplatinum(II) and (IV) compounds19974 anion;ESR chelate chelate;electron chelate;homolysis diazabutadiene diazabutadiene;methyl diazabutadiene;platinum electrochem group mesityl methyl organoplatinum photochem platinum radical radical;photohomolysis redn transfer Chelate complexes between the 1,4-diazabuta-1,3-diene ligands RN:CHCH:NR = R-DAB (R = alkyl, aryl) and the organoplatinum fragments PtMe2, PtMe4 and PtMes2 (Mes = mesityl) can be reversibly reduced to paramagnetic compds., formulated as Pt(II) or (IV) species bound by radical anion ligands (R-DAB.bul.-). EPR studies in fluid and frozen soln. support this assignment; however, the metal contribution to the singly occupied MO is higher for the paramagnetic PtII species than for the PtIV systems. Comparison with related radical complexes of the main group and transition element series reveals that even the organoplatinum(IV) compds. exhibit a relatively high degree of ligand-to-metal spin transfer as evident from small 1H(CH) and large 14N and 195Pt EPR hyperfine coupling consts. The tetramethylplatinum(IV) complexes are photoreactive; a Pt-contg. primary dissocn. product from Pt-C \textgreek{s} bond homolysis was detected by EPR spectroscopy using tBu-NO as a spin trap reagent during irradn. Group transfer reactivity also was noted for radical anions where the conversion [(R-DAB)PtMe2].bul.- $\rightarrow$ [(R-DAB)PtMe4].bul.- could be monitored by EPR spectroscopy. [on SciFinder(R)]