Synthesis and Characterization of Copper Complexes with the N-(2,6-Diisopropylphenyl)-N′-acylthiourea Ligands

Three N-(2,6-diisopropylphenyl)-N'-acylthiourea ligands [Ar'NHC(S)NHC(O)Ar; Ar' = 2,6-iPr(2)C(6)H(3); Ar = p-tBuC(6)H(4) (1, L-1), Mes (2, L-2), and 1-Naph (3, L-3)] were synthesized and compared with the homologous ligand L-0 (Ar = Ph) in terms of their resultant complexes with copper halides. The reaction of L1 with CuCl2 led to the formation of mononuclear L-1 2CuCl (4), while treatment of L-1 with CuX (X = Cl, Br) resulted in the adamantane cage complexes ((LCuX)-Cu-1)(4) (X = Cl, 5; Br, 6). These findings are similar to the results shown by its parent ligand L-0. The reaction of L-1 with CuI yielded the iodide-bridged dimeric complex [L-1 Cu-2(m-I)](2) (7), in contrast to the ligand-bridged dimer supported by L-0. L-2 readily afforded the mononuclear CuI complexes 8-10 coordinated by two or three ligands. L-3 gave monomeric (L3CuX)-Cu-3 (X = Cl, 11; Br, 12) and the iodide-bridged dimeric [(L2Cu)-Cu-3(m-I)](2) (13). L-3 can bind with CuI halides in a ratio of 1: 1 to give complexes (LCuX)-Cu-3(PPh3)(2) (14-16), when Cu2X2(PPh3)(3) (X = Cl, Br) or CuI(PPh3)(3) were used as precursors. Treatment of ((LCuCl)-Cu-1)(4) (5), (L2CuBr)-Cu-2 (8), and (L3CuCl)-Cu-3 (11), respectively, with hot EtOH resulted in the formation of trans-CuL2n' (17-19) compounds. All compounds were characterized by single-crystal X-ray diffraction studies.