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‐ i Pr 2 C 6 H 3 ; Ar = p ‐ t BuC 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 L 1 with CuCl 2 led to the formation of mononuclear L 1 2 CuCl ( 4 ), while treatment of L 1 with CuX (X = Cl, Br) resulted in the adamantane cage complexes (L 1 CuX) 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 2 Cu(µ‐I)] 2 ( 7 ), in contrast to the ligand‐bridged dimer supported by L 0 . L 2 readily afforded the mononuclear Cu I complexes 8 – 10 coordinated by two or three ligands. L 3 gave monomeric L 3 3 CuX (X = Cl, 11 ; Br, 12 ) and the iodide‐bridged dimeric [L 3 2 Cu(µ‐I)] 2 ( 13 ). L 3 can bind with Cu I halides in a ratio of 1:1 to give complexes L 3 CuX(PPh 3 ) 2 ( 14 – 16 ), when Cu 2 X 2 (PPh 3 ) 3 (X = Cl, Br) or CuI(PPh 3 ) 3 were used as precursors. Treatment of (L 1 CuCl) 4 ( 5 ), L 2 2 CuBr ( 8 ), and L 3 3 CuCl ( 11 ), respectively, with hot EtOH resulted in the formation of trans ‐CuL n ′ 2 ( 17 – 19 ) compounds. All compounds were characterized by single‐crystal X‐ray diffraction studies.