Novel Network Polymers Formed by Self-Assembly of Silver Nitrate and Pyrrol-2-yl-methyleneamine Ligands with Flexible Spacers

Abstract

This paper reports on four novel network polymers formed by self-assembly of AgNO3 and pyrrol-2-yl-methyleneamine ligands with alkyl chain spacers. The reaction of 1,3-bis(pyrrol-2-yl-methyleneamino)propane (1) with 1 or 2 equiv of AgNO3 gives network polymers 3 and 4, respectively. The structures of 3 and 4 are very similar, in which two ligands 1 are bound to two Ag(I) ions to form a distorted rectangle. These metallic rectangles are further constructed into 1D and 2D networks by nitrate ion acting as a bridge. The reaction of 1,4-bis(pyrrol-2-yl-methyleneamino)butane (2) with 1 and 2 equiv of AgNO3 is found to give network polymers 5 and 6, respectively. X-ray crystal analysis reveals that the structures of 5 and 6 are very similar, in which the 1D network is formed by direct coordination of Ag (I) with ligand 2 in a ratio of 1:1. The 1D network is further constructed to a 2D network by the nitrate ion acting as a bridge. Weak hydrogen−metal bonding (C−H···Ag) is observed in crystals of 5 and 6 and plays a crucial role on the formation of a 3D network.