EPR studies are reported on the 19-electron sandwich complex Co(cp)(Bz)+ and some of its ring-methylated derivatives in several diamagnetic host lattices and frozen solutions. The results are consistent with a d7 configuration for cobalt with the unpaired electron in the elgorbital having largely metal character. The dependence of the EPR parameters on the host lattice is mainly attributed to the rhombic splitting caused by the unsymmetrical host lattice potential acting on the dynamically ground state. The bonding parameters have been compared with those of analogous compounds with the covalency decreasing as Ni(cp)2+ > > Co(cp)(Bz)+ > Co(cp)2+ > Fe(cp)(Bz). The variation of line width with temperature has been used to derive information on the energy of the first excited Kramers doublet.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry