Bimetallic copper(II) and zinc(II) complexes of acyclic Schiff base ligands derived from amino acids

Abstract

The acyclic Schiff-base ligands (2-(OH)-5-(R 3)C 6H 2-1,3-(HC NC(R 1)(R 2)CO 2H), derived from the dialdehyde 2-hydroxy-5-R-1,3-benzenedicarboxaldehyde (R = Me or t-Bu) and two equivalents of the amino acids glycine, 2,2-diphenylglycine or phenylalanine, have been reacted with the metal acetates M(OAc) 2 (M = Cu, Zn) in the presence of triethylamine, affording the complexes [HNEt 3][M 2(CH 3CO 2) 2(2-(O)-5-( t-Bu)C 6H 2-1,3-(HC NC(R 1)(R 2)CO 2) 2] (M = Cu, R 1 = R 2 = C 6H 5, R 3 = Me ( 1); M = Zn, R 1 = R 2 = H, R 3 = t-Bu ( 2); M = Zn, R 1 = R 2 = C 6H 5, R 3 = t-Bu ( 3); M = Zn, R 1 = H, R 2 = CH 2C 6H 5, R 3 = t-Bu ( 4)) in good yields. The crystal structures of 1·MeCN, 2· 1 1 2 MeOH , 3·2MeOH, and 4·3MeOH have been determined.