Isomerization of Binuclear Cadmium Carboxylate Complexes [Cd2L2(O2CR)4]

The binuclear cadmium complexes in which the metal atoms are linked by two chelate-bridging carboxylate anions, [Cd2L2(µ2-(Рiv)2(κO,κO'-(Рiv)2] (L is 2,4-lutidine, phenanthridine, and 2,2'-bipyridine; and Рiv is pivalate anion), and the complexes with the “Chinese lantern” structure in which the cadmium atoms are linked by four bridging carboxylate anions, [Cd2L2(µ2-(Рiv)4] (L is 2,3-cyclododecenopyridine (Сdpy)) and [Cd2(L)2(µ2-(PfAc))4] (L is 1,10-phenanthroline, and PfAc is pentafluorophenylacetate anion), are considered. The two-bridge and four-bridge isomers of each binuclear [Cd2L2(Рiv)4] complex with the monodentate and chelating N-donor ligands are calculated by the density functional theory using four different approximations. The stabilities of the isomers are compared and conclusions about the factors leading to the formation of complexes of this or another structure are made on the basis of the calculation data.