Synthesis, structures and antimicrobial activities of silver(I) complexes derived from 2-propyl-1H-imidazole-4,5-dicarboxylic acid

Abstract

Two new silver(I) complexes based on propyl-substituted imidazole-4,5-dicarboxylic acid, {[Ag2(Hpimdc)(H2O)](H2O)}n (1) and {[Ag2(Hpimdc)(pda)](2H2O)}n (2) (H3pimdc=2-propyl-1H-imidazole-4,5-dicarboxylic acid; pda=1,2-propanediamine) were synthesized and structurally characterized. The single-crystal X-ray determination reveals that in complexes 1 and 2 the silver atoms are linearly coordinated. Doubly deprotonated µ3-Hpimdc2− ligand in 1 behaves as an N,O-bridging coordiation mode to offer an infinite 1D linear chain, while µ2-Hpimdc2− in 2 adopts an N,N′-bridging mode to give an infinite 1D zigzag chain in the presence of pda as an auxiliary ligand. The adjacent 1D chains in 1 are further linked to form a 2D layer structure by ligand unsupported Ag⋯Ag interactions (Ag1⋯Ag2#=3.088Å and Ag2⋯Ag2#=3.098Å). Antimicrobial testing indicates that complex 2 with MIC100 being 0.19mM was more active against Gram-negative bacteria Escherichia coli (E. coli) than complex 1 with MIC100 being 0.28mM. Complexes 1 and 2 have the slightly different influence on the growth of Gram-positive bacteria Staphylococcus aureus (S. aureus) (MIC100 being 0.28mM for 1 and 0.24mM for 2). Both 1 and 2 exhibit good inhibitory activities against jack bean urease with the respective IC50 values of 1.68±0.07 and 1.85±0.14µM.