The low temperature γ-irradiation of norbornadiene and (1,5-ciclooctadiene) platinum(II) dichloride in methyltetrahydrofurane matrix leads to a selective production of electron capture centres which were identified by ESR as platinum(I) diolefin radical anions. The Molecular Orbital calculations suggest that the unpaired electron is in a b2 orbital (assuming an idealised C2r symmetry) where the 5dyz is the major metal orbital involved. The low contribution of 5dyz to the SOMO (α2 = 0.23 as derived from the analysis of the experimental ESR parameters) implies a high delocalization on the ligands. The electronic structure of the paramagnetic species and, in particular, the large negative contributions to the calculated g-tensor elements giving rise from the low energy empty levels, were rationalised by extended Hückel MO calculations.
Matrix isolation and ESR study of platinum(I) diolefin complexes-norbornadiene and 1,5-cyclooctadiene)platinum dichloride radical anions
BUTTAFAVA, ARMANDO;FAUCITANO, ANTONIO;MARTINOTTI, FAUSTA;
1995-01-01
Abstract
The low temperature γ-irradiation of norbornadiene and (1,5-ciclooctadiene) platinum(II) dichloride in methyltetrahydrofurane matrix leads to a selective production of electron capture centres which were identified by ESR as platinum(I) diolefin radical anions. The Molecular Orbital calculations suggest that the unpaired electron is in a b2 orbital (assuming an idealised C2r symmetry) where the 5dyz is the major metal orbital involved. The low contribution of 5dyz to the SOMO (α2 = 0.23 as derived from the analysis of the experimental ESR parameters) implies a high delocalization on the ligands. The electronic structure of the paramagnetic species and, in particular, the large negative contributions to the calculated g-tensor elements giving rise from the low energy empty levels, were rationalised by extended Hückel MO calculations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
