Syntheses, crystal structures, thermal stabilities, CT-DNA, and BSA binding characteristics of a new acylhydrazone and its Co(II), Cu(II), and Zn(II) complexes

Abstract

A new acylhydrazone (C₁₂H₁₂N₄OS, HL) and its three transition metal complexes [M(HL)₂](NO₃)₂ (M = Co, I; Cu, II; Zn, III) have been synthesized. The structures of above four compounds were determined by single-crystal X-ray diffraction analyses. HL belonged to orthorhombic system and Pbca space group. I and II belonged to triclinic system and P-1 space group, whereas III belonged to monoclinic system and P2₁/C space group. The thermal stabilities of four compounds were investigated by thermogravimetric analyses, and their maximum thermal decomposition peak temperatures were all more than 240 °C, showing high thermal stabilities. The binding behaviors of four compounds with CT-DNA were determined by UV–vis absorption spectra, viscosity and microcalorimetric experiments, all presenting intercalative modes. The interactions of four compounds with BSA were determined by fluorescence spectra and microcalorimetric experiments, showing static quenching effects, and the binding constants K_A are (8.32 ± 0.36) × 10³ M⁻¹, (1.44 ± 0.40) × 10⁵ M⁻¹, (7.59 ± 0.09) × 10⁴ M⁻¹, and (4.68 ± 0.45) × 10⁵ M⁻¹ for HL, I, II, and III, respectively. Microcalorimetric experiments explored that the interactions of four compounds with CT-DNA or BSA were exothermic processes and the interaction times were all less than 43 min.

Graphical Abstract

Keywords:

• Complex
• thermal stability
• CT-DNA
• BSA
• microcalorimetry

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors are grateful to the National Natural Science Foundation of China (Nos. 21073139, 21373158 and 51173145) and Science and Technology on Combustion and Explosion Laboratory Foundation of Shaanxi (No. 6142603010301) for financial support.