Self-assembly of azine-based hydrolysis of pyridine and isatin oxamohydrazides with AgNO3; synthesis and structural studies of a novel four coordinated Ag(I)-azine 2D coordination polymer

Abstract

The novel [Ag2L(NO3)2]n complex, where L is (1E,2E)-1,2-bis(pyridin-2-ylmethylene)hydrazine, was synthesized via self-assembly of AgNO3 and the condensation product (E)-2-oxo-2-(2-(pyridin-2-ylmethylene)hydrazinyl)acetamide (L1) of pyridine-2-carboxaldehyde and oxamohydrazide. The Ag(I) promoted formation of the azine ligand L was occurred in the reaction mixture followed by in situ complexation with Ag(I) yielding the [Ag2L(NO3)2]n complex in a good yield. The azine ligand (L) acts as a bridged bidentate chelate via two Ag-N interactions with the pyridine and azine N-atoms. The coordination sphere of Ag(I) ion is completed by two Ag-O interactions from two nitrate ions. The supramolecular structure of the [Ag2L(NO3)2]n complex could be described as a two dimensional coordination polymer of complex units connected by AgN and AgO coordination interactions. The polymeric structure of the studied complex was revealed by Hirshfeld analysis and the AgN/AgO bonding interactions were described using DFT calculations. Conformational analysis combined with a study on the thermodynamic and kinetic stabilities of the possible conformers of L were also discussed. No reaction was observed in case of the halo-substituted derivatives of isatin oxamohydrazide which is explained in terms of the Parr reactivity parameters.