%0 Journal Article %1 Klein.1997b %A Klein, Axel %A Kaim, Wolfgang %A Hornung, Fridmann M. %A Fiedler, Jan %A Zalis, Stanislav. %D 1997 %J Inorganica Chimica Acta %K bipyrimidine bridged crystal dinuclear;electrochem dinuclear;electronic diplatinum;DFT mol organoplatinum oxidn platinum structure %N 1-2 %P 269--278 %R 10.1016/S0020-1693(97)05704-6 %T Electronic and molecular structure of 2,2'-bipyrimidine-bridged bis(organoplatinum) complexes in various oxidation states. Radical-bridged diplatinum species and the absence of a Pt(III)/Pt(II) mixed-valent intermediate %V 264 %X Dinuclear organoplatinum compds. RnPt(bpym)PtRn (R = Me, n = 2, 4; R = mesityl, n = 2; bpym = 2,2'-bipyrimidine) were prepd. and characterized. The neutral compds. and their neighboring oxidn. states were studied using cyclic voltammetry, 1H NMR or EPR spectroscopy and UV-Vis spectroelectrochem. Oxidn. state assignments based on these data could be made for the following compds.: R2PtII(bpym)PtIIR2, R2PtII(bpym-I)PtIIR2·-, R2PtII(bpym-II)PtIIR22-, Mes2PtIII(bpym)PtIIIMes22+, Me4PtIV(bpym)PtIVMe4, Me4PtIV(bpym-I)PtIVMe4·-. The two-electron oxidn. of Mes2Pt(bpym)PtMes2, i.e. the absence of a stable Pt(III)/Pt(II) mixed-valent state, confirms that the highest-lying occupied metal orbitals (dz2) do not communicate via the p system of the bridging ligand. A crystal structure anal. of photoreactive Me4PtIV(bpym)PtIVMe4 was obtained: space group Pbca, a = 12.830(2) \AA, b = 11.502(2) \AA, c = 12.877(2) \AA, V = 1900.3(5) \AA3, Z = 4. The structural refinement revealed elongated axial Pt-Me bonds of about 2.13 \AA. The structural features could be well reproduced by a DFT calcn. of H4PtIV(bpym)PtIVH4 which also confirmed the s character of the HOMO. Of the ligand-reduced systems, the Pt(II) species exhibits a higher degree of g anisotropy than the Pt(IV) species. Low-lying excited states of the species generated were assigned through information from vibrational structuring, solvatochromic behavior and from (spectro)electrochem. results. on SciFinder(R)

@article{Klein.1997b, abstract = {Dinuclear organoplatinum compds. RnPt(bpym)PtRn (R = Me, n = 2, 4; R = mesityl, n = 2; bpym = 2,2'-bipyrimidine) were prepd. and characterized. The neutral compds. and their neighboring oxidn. states were studied using cyclic voltammetry, 1H NMR or EPR spectroscopy and UV-Vis spectroelectrochem. Oxidn. state assignments based on these data could be made for the following compds.: R2PtII(bpym)PtIIR2, [R2PtII(bpym-I)PtIIR2]·-, [R2PtII(bpym-II)PtIIR2]2-, [Mes2PtIII(bpym)PtIIIMes2]2+, Me4PtIV(bpym)PtIVMe4, [Me4PtIV(bpym-I)PtIVMe4]·-. The two-electron oxidn. of Mes2Pt(bpym)PtMes2, i.e. the absence of a stable Pt(III)/Pt(II) mixed-valent state, confirms that the highest-lying occupied metal orbitals (dz2) do not communicate via the \textgreek{p} system of the bridging ligand. A crystal structure anal. of photoreactive Me4PtIV(bpym)PtIVMe4 was obtained: space group Pbca, a = 12.830(2) {\AA}, b = 11.502(2) {\AA}, c = 12.877(2) {\AA}, V = 1900.3(5) {\AA}3, Z = 4. The structural refinement revealed elongated axial Pt-Me bonds of about 2.13 {\AA}. The structural features could be well reproduced by a DFT calcn. of H4PtIV(bpym)PtIVH4 which also confirmed the \textgreek{s} character of the HOMO. Of the ligand-reduced systems, the Pt(II) species exhibits a higher degree of g anisotropy than the Pt(IV) species. Low-lying excited states of the species generated were assigned through information from vibrational structuring, solvatochromic behavior and from (spectro)electrochem. results. [on SciFinder(R)]}, added-at = {2019-07-15T13:41:23.000+0200}, author = {Klein, Axel and Kaim, Wolfgang and Hornung, Fridmann M. and Fiedler, Jan and Zalis, Stanislav.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/20308f47cad668f50ae94dd3692da98a5/b_schwederski}, doi = {10.1016/S0020-1693(97)05704-6}, interhash = {d182e34a76ec49762fb257ecca68501c}, intrahash = {0308f47cad668f50ae94dd3692da98a5}, issn = {0020-1693}, journal = {Inorganica Chimica Acta}, keywords = {bipyrimidine bridged crystal dinuclear;electrochem dinuclear;electronic diplatinum;DFT mol organoplatinum oxidn platinum structure}, number = {1-2}, pages = {269--278}, timestamp = {2019-07-15T11:42:10.000+0200}, title = {Electronic and molecular structure of 2,2'-bipyrimidine-bridged bis(organoplatinum) complexes in various oxidation states. Radical-bridged diplatinum species and the absence of a Pt(III)/Pt(II) mixed-valent intermediate}, volume = 264, year = 1997 }