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

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 (beta-sheets or 4,4-networks) via N-H center dot center dot center dot 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 beta-sheets connected by the silver coordination bonds.