EPR Spectra of Some Salts of Bis[eta~5-l,2-Dicarbollyl]nickeliate(III)(1-)Anion [Ni~(III)(eta~5-l,2-B_9C_2H_11)_2]

摘要

Some salt-like complexes of the cluster anion [Ni~(III)(eta)~5-l,2-B_9C_2H_11)_2]~- ([NiCb_2]~-),containing paramagnetic Ni~(3+) ion, with cations Cs~+, (CH_3)_4N~+, [MnPhen_3]~(2+) (where Phen is 1,10-phenanthroline) are studied by EPR method at 77 K and 300 K. A neutral complex [MnPhen_2(NCS)_2] is also studied for comparison.The synthesis procedure and X-ray diffraction analysis of [MnPhen_3][NiCb_2]_2 complex with paramagnetic ions Mn~(2+) (3d~5) and Ni~(3+) (3d~7) are described.The EPR data of isostructural complexes [MnPhen_3][NiCb_2]_2 and [MnPhen_3][CoCb_2]_2 are reported.No exchange or dipole-dipole interaction was observed between two paramagnetic ions (Mn~(2+) and Ni~(3+)) simultaneously present in a complex structure.The temperature changes in EPR spectra of solid compounds are caused by rearrangements in the Mn~(2+) surrounding.In the case of a salt with a compact spherical Cs~+ ion,the local perturbation in a second coordination sphere of [NiCb_2]~- anion leads to redistribution of the electron density and changes in g-factor.