Département de chimie moléculaire

Dinuclear metal compds. [(LnM)($μ$-BL·-)(MLn)]k involving radical anions of bridging ligands BL such as 2,2'-azobispyridine or 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine and coordinated inorg. or organometallic complex fragments MLn contg. copper(I), rhenium(I), ruthenium(II), osmium(II), rhodium(III) or iridium(III) were studied in frozen solns. using high field EPR spectroscopy at W band (95 GHz) or higher frequencies. The generally small but still rather variable anisotropy of the g factor shows typical patterns reflecting the specific metal/ligand interactions, the competition between bridging and ancillary ligands for spin d., and the spin-orbit coupling consts. of the metals. The EPR data thus specify the structural data as obtained from x-ray crystallog. for a std. series of diphosphinocopper(I) complexes involving the radical ligands indicated. The (RNNR)·- group can be placed next to the related superoxide (OO)·- as a paramagnetic ligand with specific geometrical and electronic structure. [on SciFinder(R)]