Bis[(S)-N-2-(2-butyl)-3,5-dichlorosalicylidene-aminato-κ2N,O]copper(II)

The title compound, [Cu(C11H12Cl2NO)(2)], has a compressed tetrahedral trans-[CuN2O2] coordination environment. The absolute configuration is found to be A(S,S) for the crystal examined. The Cu-N bond distances are 1.969 (4) and 1.971 (4) Angstrom, while the Cu-O bond distances are 1.886 (3) and 1.892 (3) Angstrom. The ligands, containing optically active (S)-2-butylamine moieties and electron-withdrawing Cl substituents, lead to an umbrella conformation of the overall molecule. On heating to 387 K, a structural phase transition is observed, probably involving a change in coordination geometry.