NMR Study on the Ru-dimer System with Valence Fluctuation

Substituting effect of CF3 to the Ru-based binuclear complex [{RuIII(acac)2}2(μ-OEt)2], in which S = 1/2 spin dimer takes the singlet ground state have been investigated by means of the magnetic susceptibility χ and the longitudinal nuclear spin relaxation rate T1-1 of 1H/19F-NMR. In CF3-substituted complex [{RuIII(fhma)2}2(μ-OMe)2], we have observed the prominent magnetic response both in χ and T1−1. This behavior is attributed to the slight change in the Ru valence state due to the substitution.