Synthesis, Characterization, and Crystal Structures of [Cu(ca2en)(PPh3)(X)] (X = Cl, Br, I, NCS, N3) Complexes

Abstract

Novel mixed-ligand copper(I) complexes, [Cu(ca₂en)(PPh₃)X] (ca₂en = N,N′-bis(trans-cinnamaldehyde)-1,2-diaminoethane, X = Cl (1), Br (2), I (3), NCS (4), N₃ (5)), have been synthesized and characterized by ¹H and ³¹P NMR spectroscopy, infrared spectroscopy, and elemental analyses. The single crystal X-ray structures of complexes (1)–(5) have been determined. All five complexes reveal discrete monomeric structures in the crystal. The geometry around the copper atom is in each case a distorted tetrahedron, with the distortion most pronounced in (3). The NCS⁻ and N₃⁻ are coordinated as terminal ligands and the NCS⁻ ligand is N-bonded in (4). Dynamic ³¹P NMR studies show partial bond breaking in solution.