%0 Journal Article %1 Klein.1997 %A Klein, Axel %A Hasenzahl, Steffen %A Kaim, Wolfgang. %D 1997 %J Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry %K 4 anion;ESR chelate chelate;electron chelate;homolysis diazabutadiene diazabutadiene;methyl diazabutadiene;platinum electrochem group mesityl methyl organoplatinum photochem platinum radical radical;photohomolysis redn transfer %N 12 %P 2573--2577 %T EPR study of electron transfer and group transfer in organoplatinum(II) and (IV) compounds %X 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 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)

@article{Klein.1997, abstract = {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)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Klein, Axel and Hasenzahl, Steffen and Kaim, Wolfgang.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/20f40a77fe96947fad5e59587f36f3740/huebleriac}, interhash = {56b06388224c0dc3784900a4204d16c5}, intrahash = {0f40a77fe96947fad5e59587f36f3740}, issn = {0300-9580}, journal = {Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry}, keywords = {4 anion;ESR chelate chelate;electron chelate;homolysis diazabutadiene diazabutadiene;methyl diazabutadiene;platinum electrochem group mesityl methyl organoplatinum photochem platinum radical radical;photohomolysis redn transfer}, number = 12, pages = {2573--2577}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {EPR study of electron transfer and group transfer in organoplatinum(II) and (IV) compounds}, year = 1997 }