A new polymorph of six-coordinated bis(5,5′-dimethyl-2,2′-bipyridine) nitratocopper(II) nitrate and its DNA interactions

作者：Gonçalves, Guilherme R.; de Carvalho, Alexandre B.; Honorato, João; Oliveira, Katia M.; Correa, Rodrigo S.^*

来源：Journal of Molecular Structure, 2021, 1224: 129035.

DOI：10.1016/j.molstruc.2020.129035

• Binding constant
• Crystalline form
• Five-coordinated
• Hirshfeld surfaces
• Intermolecular contacts
• Single crystal x-ray diffraction
• Spectrophotometric titrations
• Spectroscopic technique

Here, we present a new polymorph of the [Cu(5mebipy)(NO3)]NO3complex (1, Form II), where 5mebipy means 5,5′-dimethyl-2,2′-bipyridine. The copper(II) complex 1 was characterized by spectroscopic techniques and single-crystal X-ray diffraction. The Form II presents a six-coordinated structure, meanwhile the Form I, previously reported, is five-coordinated with the nitrate ligand as monodentate. The molecular structures of both crystalline forms were compared based on intramolecular aspects using Kleywegt's analysis and the intermolecular contacts evaluated by Hirshfeld surface studies. Moreover, the interaction of the complex [Cu(5mebipy)(NO3)]+with CT-DNA was carried out using viscosity and spectrophotometric titrations, exhibiting a binding constant of 2.57 ×104M −1. This study contributes to explore the intra and intermolecular details of the new polymorph of the complex [Cu(5mebipy)(NO3)]NO3and its capability to interacts with CT-DNA.