PUMA publications for /user/b_schwederski/complex;tungstenhttps://puma.ub.uni-stuttgart.de/user/b_schwederski/complex;tungstenPUMA RSS feed for /user/b_schwederski/complex;tungsten2024-03-29T09:00:54+01:00Triple-decker sandwich complexes with cyclo-P6 as middle deckhttps://puma.ub.uni-stuttgart.de/bibtex/2f120813f4d6ce622b9843b62364b122e/b_schwederskib_schwederski2019-07-15T13:41:23+02:00complex;triple complex;tungsten crystal cyclophosphorus decker hexaphosphacyclohexane metal sandwich sandwich;mol structure structure;vanadium tungsten vanadium;redox <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Otto J. Scherer" itemprop="url" href="/person/1912db1440e6cde24b5391db9bd05cdde/author/0"><span itemprop="name">O. Scherer</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Joachim Schwalb" itemprop="url" href="/person/1912db1440e6cde24b5391db9bd05cdde/author/1"><span itemprop="name">J. Schwalb</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Herbert Swarowsky" itemprop="url" href="/person/1912db1440e6cde24b5391db9bd05cdde/author/2"><span itemprop="name">H. Swarowsky</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Gotthelf Wolmershaeuser" itemprop="url" href="/person/1912db1440e6cde24b5391db9bd05cdde/author/3"><span itemprop="name">G. Wolmershaeuser</span></a></span>, </span><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang Kaim" itemprop="url" href="/person/1912db1440e6cde24b5391db9bd05cdde/author/4"><span itemprop="name">W. Kaim</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Renate. Gross" itemprop="url" href="/person/1912db1440e6cde24b5391db9bd05cdde/author/5"><span itemprop="name">R. Gross</span></a></span></span>. </span><span class="additional-entrytype-information"><span itemtype="http://schema.org/PublicationIssue" itemscope="itemscope" itemprop="isPartOf"><em><span itemprop="journal">Chemische Berichte</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">121 </span></span>(<span itemprop="issueNumber">3</span>):
<span itemprop="pagination">443--449</span></em> </span>(<em><span>1988<meta content="1988" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Chemische Berichte3443--449Triple-decker sandwich complexes with cyclo-P6 as middle deck1211988complex;triple complex;tungsten crystal cyclophosphorus decker hexaphosphacyclohexane metal sandwich sandwich;mol structure structure;vanadium tungsten vanadium;redox Cothermolysis of white phosphorus (P4) with [(\textgreek{h}5-C5Me5)2(CO)nW2] (C5Me5 = pentamethylcyclopentadienyl; n = 4, 6) as well as [(\textgreek{h}5-C5Me4R)V(CO)4] affords the triple-decker sandwich complexes [{(η5-C5Me5)W}2(\textgreek{m},\textgreek{h}6-cycloP6)] (I) and [{(η5-C5Me4R)V}2(\textgreek{m},\textgreek{h}6-cycloP6)] (II; R = Me, Et). I and II (R = Et) were characterized by x-ray structure analyses. Electrochem., ESR, and electronic spectroscopy measurements of I, II (R = Me), [{(η5-C5Me5)Cr}2-P5], and [{(η5-C5Me5)Mo}2-P6] were reported. An empirical valence-electron rule for triple-decker complexes is derived. [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> and <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)]Coordination chemistry of reduced nitrogen heterocycles. Dinuclear pentacarbonyl complexes of molybdenum and tungsten with paramagnetic bridging ligandshttps://puma.ub.uni-stuttgart.de/bibtex/22f0d0147d4e2159f97c78c032964ce27/b_schwederskib_schwederski2019-07-15T13:41:23+02:00binuclear carbonyl complex nitrogen tungsten bipyridine complex;carbonyl complex;molybdenum complex;pyrazine complex;quinoxaline complex;tungsten heterocycle heterocycle;dipyridylethene heterocycle;phenazine molybdenum <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/10785748fa5efd399aa907c27c01e83ad/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">Chemische Berichte</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">115 </span></span>(<span itemprop="issueNumber">3</span>):
<span itemprop="pagination">910--918</span></em> </span>(<em><span>1982<meta content="1982" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Chemische Berichte3910--918Coordination chemistry of reduced nitrogen heterocycles. Dinuclear pentacarbonyl complexes of molybdenum and tungsten with paramagnetic bridging ligands1151982binuclear carbonyl complex nitrogen tungsten bipyridine complex;carbonyl complex;molybdenum complex;pyrazine complex;quinoxaline complex;tungsten heterocycle heterocycle;dipyridylethene heterocycle;phenazine molybdenum L[M(CO)5]2- (M = Mo, W; L = pyrazine, 2,5-dimethylpyrazine, quinoxaline, phenazine, 4,4'-bipyridine, (E)-1,2-di-4-pyridylethene) were prepd. by reaction of M(CO)6 with the radical anions of the heterocycles L in THF or dimethoxyethane. The metal carbonyl coordination was established by high resoln. ESR which also provided data on the spin distribution and on the conformation of the radical complexes. [on SciFinder(R)]Coordination ambivalence and fluxional behavior in mono- and binuclear pentacarbonyltungsten complexes of pteridine and its deaza derivativeshttps://puma.ub.uni-stuttgart.de/bibtex/2248687dc2e2486673fb2c4a8d5656820/b_schwederskib_schwederski2019-07-15T13:41:23+02:00carbonyl complex;triazanaphthalene complex;tungsten deaza deriv deriv;naphthyridine fluxionality pteridine tungsten <span data-person-type="author" class="authorEditorList "><span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Christian Bessenbacher" itemprop="url" href="/person/1c4ede1b93002d0a9a60a50513eec5f13/author/0"><span itemprop="name">C. Bessenbacher</span></a></span>, </span> and <span><span itemtype="http://schema.org/Person" itemscope="itemscope" itemprop="author"><a title="Wolfgang. Kaim" itemprop="url" href="/person/1c4ede1b93002d0a9a60a50513eec5f13/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 Organometallic Chemistry</span>, </em> <em><span itemtype="http://schema.org/PublicationVolume" itemscope="itemscope" itemprop="isPartOf"><span itemprop="volumeNumber">369 </span></span>(<span itemprop="issueNumber">1</span>):
<span itemprop="pagination">83--103</span></em> </span>(<em><span>1989<meta content="1989" itemprop="datePublished"/></span></em>)</span>Mon Jul 15 13:41:23 CEST 2019Journal of Organometallic Chemistry183--103Coordination ambivalence and fluxional behavior in mono- and binuclear pentacarbonyltungsten complexes of pteridine and its deaza derivatives3691989carbonyl complex;triazanaphthalene complex;tungsten deaza deriv deriv;naphthyridine fluxionality pteridine tungsten WL(CO)5 (L = pteridine (pte), 1,5-naphthyridine, (npt), 1,4,5-triazanaphthalene (tan), 1,4,6-triazanaphthalene) and W2(CO)10L1 (L1 = pt, npt) were prepd. Unambiguous identification of coordination sites was only possible by use of high-resoln. 1H NMR because the chem. shifts and spin-spin coupling consts. are characteristically affected by W(CO)5-coordination to neighboring N centers. Fluxional behavior with respect to the peri coordination sites was obsd. for W(CO)5(1,4,5-tan) and W(CO)10(pte). Competition between the more basic pyridine or pyrimidine and the better \textgreek{p} backdonating pyrazine N centers leads to various positions for the nondegenerate equil. between linkage isomers. Cyclic voltammetry and solvent-dependent charge transfer absorption spectra of the complexes reveal low-lying \textgreek{p}* levels which can become populated after chem. or electrochem. redn., the spin distribution in the centrosym. binuclear complex of 1,5-naphthyridine anion radical was fully characterized using ESR and results from MO calcns. [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)]