Synthesis and Characterization of Diacylthiourea and Diacylthioureato Cu(I) Complexes

Abstract A series of six disubstituted diacylthioureas 1,3‐ and 1,4‐C 6 H 4 [C(O)NHC(S)NR 1 R 2 ] 2 (L 1–6 ) were synthesized with varied R n substituents (R 1 =R 2 =Et for L 1,2 ; R 1 =R 2 =Bn for L 3,4 ; R 1 = i Pr and R 2 =Ph for L 5 ( 1 ) and L 6 ( 2 )). Treatment of L n with Cu(I) halide precursors CuX(PPh 3 ) 3 (X=Cl, Br, I) produced the discrete binuclear adducts L n [CuX(PPh 3 ) 2 ] 2 ( 3 – 11 and 14 – 16 ; n=1–3 and 6) by binding to Cu(I) centres via the monodentate‐S mode. In contrast, L 4 and L 5 yielded only the chloride products of binuclear L 4 [CuCl(PPh 3 ) 2 ] 2 ( 12 ) and mononuclear L 5 CuCl(PPh 3 ) 2 ( 13 ), respectively, with one S arm in the latter remaining dangling, while bromide or iodide analogues were not available for L 4 and L 5 , possibly due to the steric hindrance imposed by larger halide anions or bulky isopropyl substituents. The reactions of L n with nitrate [Cu(NO 3 )(PPh 3 ) 2 ] led to the double‐deprotonation of ligand protons to generate dianions L n ′ (1,3‐/1,4‐C 6 H 4 [C(O)NC(S)NR 1 R 2 ] 2 2− ) and led to the consequent formation of binuclear diacylthioureato Cu(I) complexes L n ′[Cu(PPh 3 ) 2 ] 2 (n=1 ( 17 ), 2 ( 18 ), 4 ( 19 )) via the κ‐O,S‐bidentate mode. The obtained ligands and complexes were spectroscopically and structurally characterized. These Cu(I) products ( 3 – 19 ) were experimentally used as catalysts for the oxidation of 1‐phenylethanol.