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-iPr2C6H3; Ar = p-tBuC6H3 (1, L1), Mes (2, L2), 1-Naph (3, L3)) were synthesized and compared with the homologous ligand L0 (Ar = Ph) in terms of their resultant complexes with copper halides. Reactions of L1 with CuCl2 led to the formation of mononuclear L12CuCl (4), while treatment of L1 with CuX (X = Cl, Br) resulted in the adamantane cage complexes (L1CuX)4 (X= Cl, 5; Br, 6). These findings are similar to the results shown by its parent ligand L0. The reaction of L1 with CuI yielded the iodide-bridged dimeric complex [L12Cu(μ-I)]2 (7), in contrast to the ligand-bridged dimer supported by L0. L2 readily afforded the mononuclear copper(I) complexes (8-10) coordinated by two or three ligands. L3 gave monomeric L33CuX (X = Cl, 11; Br, 12) and iodide-bridged dimeric [L32Cu(μ-I)]2 (13). L3 can form with Cu(I) halides in a ratio of 1:1 and in the presence of PPh3 the complexes L3CuX(PPh3)2 (14-16). Treatment of (L1CuCl)4 (5), L22CuBr (8), and L33CuCl (11), respectively, with hot EtOH resulted in the formation of trans-CuLn'2 (17-19) compounds. All compounds were characterized by single crystal X-ray diffraction studies.