An electron spin resonance study of dimeric oranotitanium(III) carboxylates

Abstract

The e.s.r. spectra of a series of binuclear titanium(111) carboxylates, [CpTi(O₂CR)₂]₂, both in toluene solution or in a polycrystalline state, are characteristic of a triplet (S = 1) state. The zero-fieldsplitting parameter D lies in the range D = 0.055 ± 0.004 cm^-1 whereas E is close to zero. The g values for five R-substituents are g/=1.94 ± 0,02 and g// = 2.00 ± .03; the forbidden ΔM = 2 resonance occurs at g_av = 3.96 ± 0.09. Pairs of titanium atoms (electron configuration 3d¹) arebelieved to be strongly coupled antiferromagnetically through a d_xy(Ti₁) // π(carboxy1ate)//d_xy(Ti₂) superexchange pathway.