Electron spin resonance study of titanium(III) trichloride in pyridine solutions

Abstract

The X-band e.s.r. spectra of titanium(III) trichloride in pyridine solution at room temperature and 77 K provide evidence to show that the molecular species formed in greatest amount is a dimeric form of the bispyridinetitanium(III) chloride complex which is characterised both in the liquid phase and at 77 K by triplet-state spectra. The observed spectra at 77 K is best accounted for by consideration of an interaction spin Hamiltonian which involves an angular dependence of the zero-field splitting term. Computer simulation of the experimental line-shapes has enabled a determination of the magnetic parameters associated with the various titanium(III) trichloride–pyridine complexes. The determination of these parameters in the case of the dimeric species includes an evaluation of the internuclear separation and the symmetry properties of the pair of titanium(III) ions which have been used to indicate their structure.