Crystal structures of two copper(II) ternary complexes of N-salicylidene-tryptophanato with 2-aminopyridine and 2-aminopyrimidine

Two ternary copper(II) complexes of a tridentate Schiff base of the N-salic ylidene-tryptophanato type: [Cu(Sal-Trp)(2-aminopyrimidine)] (1) and [Cu(Sa l-Trp)(2-aminopyridine)]. methanol (2b) have been synthesized and structura lly characterized. Single crystal X-ray diffraction analyses show that the copper atom exhibits in 1 a distorted square-pyramidal geometry and in 2b a square-planar geometry, with the tridentate Sal-Trp and one heterocyclic n itrogen of the ligand in the basal plane. In 1, a weakly bonded nitrogen at om of a second 2-aminopyrimidine molecule is located in the apical position . This second ligand connects to an adjacent unit through the basal plane y ielding polymeric chains. In both structures a C-H . . . pi interaction bet ween the heterocyclic ligand and the indole moiety is present but stacking interactions are not observed. (C) 2001 Elsevier Science Ltd. All rights re served.