ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Formation of a new Cu^II–triazole ester complex from 1,2-cyclohexanedione-bis(p-bromobenzohydrazone) compound as a consequence of copper(II)-catalyzed click reaction

Ahmed Jasim M. Al-Karawi, Al-Ameen Bariz OmarAli, Necmi Dege, and Sevgi Kansız

Department of Chemistry, College of Science, Mustansiriya University, Baghdad, Iraq

E-mail: ahmedalkarawi@uomustansiriyah.edu.iq

Received: 11 January 2021  Accepted: 17 March 2021

Abstract:

Reaction of 1,2-cyclohexanedione-bis(p-bromobenzohydrazone) (CBB) as a bis-aroyl-hydrazone derivative with copper(II) nitrate trihydrate in acetonitrile under ambient conditions produced a mononuclear Cu(II) complex [Cu(TE)(NO₃)₂] (TE: triazole-ester) (1). TE is an intermediate which is formed in situ during the oxidation of CBB by Cu(II) ion based on so-called copper(II)-catalyzed click reaction. CBB and 1 are characterized with various techniques. On the basis of single-crystal X-ray crystallography, compound 1 is confirmed as a 4-coordinate mononuclear Cu(II) complex with a distorted square planner geometry. In this compound, copper is bound to the 1-N of two monodentate triazole ester molecules and two monodentate nitrate ions. Moreover, the antimicrobial activity of CBB and 1 against some selected pathogenic bacteria was investigated. Due to this study, these compounds showed a good antibacterial activity. In addition, the Hirshfeld surface analysis (d_norm surface and two-dimensional fingerprint plots) was performed to reveal the nature of intermolecular interactions in CBB and 1. The most important contributions for the crystal packing of CBB are mainly from H…H (28.8%), Br…H/H…Br (23.2%) and C…H/H…C (19.5%) interactions, while the most important contributions for the crystal packing of 1 are found to be from H…H (27%), O…H/H…O (23.7%) and Br…H/H…Br (19%) interactions.

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01614-x

Chemical Papers 75 (8) 3901–3914 (2021)