Synthesis, Crystal Structure and Cytotoxicity of a Novel 1D Polymeric Silver(I) Complex Derived From 3,5-Diaminocarboxylic Acid

Abstract

Reaction of 3,5-diaminobenzoic acid (HL) with silver oxide in 30 % ammonia afforded a novel 1D polymeric silver(I) compound, [AgL]n·nH2O. Structure of the complex was characterized by various physico-chemical methods and single crystal X-ray diffraction. X-ray crystal structure determination reveals that the complex crystallizes as monoclinic space group Cc, with unit cell dimensions a = 13.497(2) Å, b = 9.558(2) Å, c = 7.010(1) Å, β = 91.447(2)°, V = 904.1(3) Å3, Z = 4, R1 = 0.0461, wR2 = 0.1240. The asymmetric unit of the compound contains a [AgL] complex moiety and a water molecule of crystallization. Each Ag atom is coordinated by two amino nitrogen atoms, forming a linear geometry. The ligand bridged two silver atoms has a distance of 7.683(2) Å. In the crystal structure of the compound, the silver atoms are linked through 3,5-diaminobenzoate ligands, forming chains running along the a axis. The chains are further linked by water molecules through intermolecular N–H∙∙∙O and O–H∙∙∙O hydrogen bonds, to generate a three-dimensional network. In addition, π···π interactions are observed among the chains. Silver complexes are cytotoxic to most cancer cell lines. The complex in the present work is cytotoxic on human lung cancer cell line A549, with the IC50 value of 11.5 ± 1.7−μM.