Crystal structure analysis of supramolecular arrangements in bis(1-isoquinolinecarboxamide)alkanes and their Ag(i) complexes

Abstract

A homologous series of bis(1-isoquinolinecarboxamide)alkane derivatives (3a–f) with two to seven carbon atoms in the alkyl bridge and their Ag(I) complexes (4a–f) have been synthesized. Four ligand and five Ag(I) complex crystal structures were obtained by single crystal X-ray diffraction and analyzed in terms of: a) their structural patterns based on intra- and intermolecular hydrogen bonds which were compared to those of bis(2-quinolinecarboxamide)alkanes (1n) and bis(6-quinolinecarboxamide)alkanes (2n) attending to specific geometrical parameters and b) the Ag(I) coordinate bond effect on these patterns and the amide-to-amide hydrogen bonds. The crystal structures of the ligands 3a, 3c, 3d and 3e synthesized here show amide-to-amide interactions, the same as those occurring in the 2n derivatives, forming one or two-dimensional structures (β-sheets or 4,4-networks) via N–H⋯O_(amide) hydrogen bonds. The coordinate bond in the 4n complexes predominates over the amide-to-amide hydrogen bond giving rise to structures ranging from discrete complexes to three-dimensional coordination polymers. Only the 4c complex merges supramolecular β-sheets connected by the silver coordination bonds.