An antibacterial silver(I) supramolecular network assembled from thiophene-2,5-dicarboxylate and benzimidazole

Abstract

A silver(I) supramolecular network Ag(BIm)₂(HTDC) (1) was assembled from thiophene-2,5-dicarboxylic acid (H₂TDC) and benzimidazole (BIm) ligands and characterized by single-crystal X-ray diffraction, elemental analysis, FT-IR, and thermal gravimetric analysis. Complex 1 possesses a two-dimensional structure with a hydrogen-bonded grid network, in which the adjacent [Ag(BIm)₂]⁺ cations and (HTDC)^– are bridged via N–H···O hydrogen bonds forming undulating ribbons. The antibacterial properties of 1 were investigated by determining the minimal inhibitory concentration (MIC), the growth curve of bacteria and zone inhibition value assays against Gram-negative bacterium, Escherichia coli, and Gram-positive bacterium, Staphylococcus aureus. The MIC of 1 against E. coli and S. aureus are 15-20 ppm and 20-30 ppm which showed that 1 has higher antibacterial activity than commercial silver nanoparticles. The mechanism of antibacterial activity of 1 was also discussed.

Graphical Abstract

Keywords:

• Silver supramolecular network
• crystal structure
• antimicrobial activity
• thiophene-2,5-dicarboxylate
• benzimidazole

Acknowledgment

The authors thank Dr Wenjie Yuan for many helpful suggestions for antibacterial experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number U1607101]; Natural Science Foundation of Liaoning Province [grant number 2015020199]; and the Fundamental Research Funds for the Central Universities of China [grant number DUT17LK44].