Influence of anion on the network structure of one dimensional silver(I) coordination polymers of dicompartmental N,N-donor ligands

Three one-dimensional silver(I) coordination polymers {[AgL1]NO3}n (1), {[AgL2]ClO4}n (2) and {[AgL2]NO3}n (2a), where L1 (pyridin-2-ylmethylene-(4-{[(pyridin-2-ylmethylene)-amino]-methyl}-benzyl)-amine) is a dicompartmental iminopyridine ligand derived from the Schiff-base condensation of α,α′-diamino-p-xylene and pyridine-2-carboxaldehyde and L2 (N-(4-((methyl(pyridin-2-ylmethyl)amino)methyl)benzyl)-N-methyl(pyridin-2-yl)methanamine) is the reduced N-methyl derivative of L1, have been isolated from the reaction of ligands with various silver salts. Six different conformations of L1 are known that give rise to different network structures for {[AgL1]ClO4}n. X-ray single crystal structure of polymer 1·5H2O reveals that the asymmetric unit contains five water molecules that form a two-dimensional hydrogen bonding network with nitrate counter anion. A new conformer of L1 is observed in the polymeric structure of 1·5H2O. Coordination polymers 2 and 2a, both made of [AgL2]+ repeating unit, contains different conformers of L2. As a result, different polymeric structures are obtained for 2 and 2a. The effect of counterion on the ligand conformation and subsequently on the polymeric structure is reported.

Graphical abstractThree silver(I) coordination polymers derived from the reaction of silver salts and bis(bidentate) N,N-donor ligands are presented. Counter-anions have been shown to affect the polymeric architecture by changing the conformation of the flexible ligands.Figure optionsDownload full-size imageDownload as PowerPoint slide