EPR Spectra of Some Salts of Bis[η5-1,2-Dicarbollyl]nickeliate(III)(1-) Anion [NiIII (η 5-1,2-B9C2H11)2

Abstract

Some salt-like complexes of the cluster anion [NiIII (η5-1,2-B9C2H11 )2]− ([NiCb2]−), containing paramagnetic Ni3+ ion, with cations Cs+, (CH3)4N+, [MnPhen3]2+ (where Phen is 1,10-phenanthroline) are studied by EPR method at 77 K and 300 K. A neutral complex [MnPhen2(NCS2] is also studied for comparison. The synthesis procedure and X-ray diffraction analysis of [MnPhen3][NiCb2]2 complex with paramagnetic ions Mn2+ (3d5) and Ni3+ (3d7) are described. The EPR data of isostructural complexes [MnPhen3][NiCb2]2 and [MnPhen3][CoCb2]2 are reported. No exchange or dipole-dipole interaction was observed between two paramagnetic ions (Mn2+ and Ni3+) simultaneously present in a complex structure. The temperature changes in EPR spectra of solid compounds are caused by rearrangements in the Mn2+ surrounding. In the case of a salt with a compact spherical Cs+ ion, the local perturbation in a second coordination sphere of [NiCb2]− anion leads to redistribution of the electron density and changes in g-factor.