Three Chiral Cyanide-Bridged Cr-Cu Complexes: Synthesis, Crystal Structures and Magnetic Properties

摘要

Two trans-dicyanidochromium(III)-containing building blocks and one chiral copper(II) compound have been employed to assemble cyanide-bridged heterometallic complexes, resulting in three chiral cyanide-bridged Cr(III)-Cu(II) complexes, {[Cu(L-1)(2)Cr(L-3)(CN)(2)]ClO4}(2) center dot CH3OH center dot H2O (1a, L-1 = (S,S)-1,2-diaminocyclohexane, H2L3 =1,2-bis(pyridine-2-carboxamido)benzene), {[Cu(L-2)(2)Cr(L-2)(CN)(2)]ClO4}(2 )center dot CH3OH center dot H2O (1b, L-2 = (R,R)-1,2-diaminocyclohexane) {[Cu(L-3)(2)Cr(L-4)(CN)(2)] [Cr(L-4)(CN)(2)]} center dot CH3OH center dot 2H(2)O (2), (H2L4 = 1,2-bis(pyridine-2-carboxamido)-4-chlorobenzene). All the three complexes have been characterized by elemental analysis, IR spectroscopy and X-ray structure determination. Single-crystal X-ray diffraction analysis shows that the two enantiomeric complexes 1a, 1b and the complex 2 belong to cyanide-bridged cationic binuclear structure type with ClO4- or the anionic cyanide building block as balance anion for complexes 1a, 1b or 2, respectively. Investigation of the magnetic properties of the complexes 1a and 2 reveals the weak ferromagnetic coupling between the neighboring Cr(III) and Cu(II) ions through the bridging cyanide group.