Crystal structure, optical properties, Hirshfeld surface analysis and bactericidal activity of a new organic-inorganic hybrid: 4-methyl-1-(2'-nitrobenzyl)pyridinium tetrabromocuprate(II)

Abstract

In this work, an organic-inorganic hybrid crystal with excellent bactericidal activity, 4-methyl-1-(2'-nitrobenzyl)pyridinium tetrabromocuprate(II) ([4Me2NO₂BzPy]₂[CuBr₄]), was synthesized by the crystal growth by a slow evaporation method and characterized. [4Me2NO₂BzPy]₂[CuBr₄] crystallized in the orthorhombic space group Pna2₁. Hirshfeld surface analysis indicated that the H···H (28.8%), H···Br/Br···H (27.0%), and O···H/H···O (17.5%) interatomic contacts played a primary role in contributing to the stacking of the crystals. Thermogravimetric analysis showed that the material was stable up to 192.5 °C. The charge transfer interaction between anions and cations was explained by UV-Vis diffuse reflectance spectroscopy. [4Me2NO₂BzPy]₂[CuBr₄] exhibited favorable bactericidal activity against Staphylococcus aureus and Escherichia coli.

GRAPHICAL ABSTRACT-PICTOGRAM

RESEARCH HIGHLIGHTS

1. An inorganic-organic hybrid salt[4Me2NO₂BzPy]₂[CuBr₄] was synthesized and characterized.

2. Hirshfeld surface analysis indicated the primary intermolecular interactions were H···H, Br···H and O···H interactions.

3. The salt exhibited favorable thermal stability and could be used in applications below 192.5 °C.

4. The salt had an optical band gap of 1.73 eV and was a typical semiconductor material with good optical properties.

5. The as-synthesized salt exhibits good antibacterial activities against S. aureus and E. coli.

Keywords:

• Antibacterial activities
• crystal structure
• Hirshfeld surface analysis
• optical properties
• organic-inorganic hybrid
• Tetrabromocuprate(II)

Disclosure statement

No potential conflict of interest was reported by the authors.

CRediT authorship and contribution statement

Pei-Shan Zhong and Qing-Zhi Zheng: Conceptualization, Writing-original draft preparation. Bao-Yi Hu and Yan Jiang: Investigation and Formal analysis. Xin-Ran Li and Xiang-Ling Li: Investigation, Project administration. Jia-Rong Zhou and Chun-Lin Ni: Supervision, Methodology, Writing-review and editing. All authors have read and agreed to the published version of the manuscript.

Additional information

Funding

This work was supported by the Science and Technology Project (No. 2016A010103025) and 2023105641081 from Guangdong Science and Technology Department.