Synthesis and magnetism of tetrachlorophthalato-bridged manganese(II) binuclear complexes

Abstract

Four novel manganese(II) binuclear complexes have been prepared and characterized, namely [Mn2(TCPHTA)(L)J-(C104)2 [where L is 2,2'-bipyridyl (bipy), 1,10-phenanthroline (phen), 4,4'-dimethyl-2,2'-bipyridyl (Me2bipy) or 5-nitro-l,10-phenanthroline (NO2-phen) and TCPHTA is the tetrachlorophthalate dianion]. Based on i.r. spectra, elemental analyses, conductivity measurements, extended tetrachlorophthalato-bridged structures consisting of two manganese(II) ions in which each manganese(II) ion has a distorted octahedral environment are proposed for these structures. The temperature dependence of the magnetic susceptibility for [Mn2(TCPHTA)(phen)4]-(C104)2.H20 was measured over the 4--300 K range and the observed data were successfully simulated by an equafionbased on the spin Hamiltonian operator (H = -2JS1 "$2), giving the exchange integral J = -1.05 cm-1.This result is indication of a weak antiferromagnetic spin exchange interaction between the metal ions.