A novel iodo bridged 1D CuI coordination polymer containing N,N-bidentate Schiff base ligand: Synthesis, structure, theoretical studies, electrochemical properties, and catalytic activity in the synthesis of tetrahydropyrimidines

Abstract

In this study, a new 1D polymeric Cu(I) complex [Cu(L2Cl)I]n, where L = N,N′-bis(2-chlorobenzylidene)ethane-1,2-diamine, was synthesized and characterized using different analytical approaches, comprising 1H NMR, FT-IR, and CHN analysis. The geometrical features of the complex were determined through the single crystal X-ray diffraction (SC-XRD) method, which revealed that the copper atom is coordinated to the N atoms of the Schiff base. The bond angles surrounding Cu(I) ion indicated a somewhat distorted trigonal planar geometry of the complex. Hirshfeld surface analysis (HSA) was used to investigate the non-covalent intermolecular interactions, while theoretical studies were conducted utilizing DFT with B3P86/Def2-TZVP level of theory. The consistency between theoretical findings and experimental bond lengths of the [Cu(L2Cl)I]n confirmed the reliability of the theoretical conclusions. To better understand the intermolecular charge transfer features of the [Cu(L2Cl)I]n, the natural bond orbital as well as Atoms in Molecules analyses were also performed. The electrochemical behavior of the Cu(I) complex was explored at 25 °C using cyclic voltammetry in a pH 7.0 buffered solution. It is established that the quasi-reversible mechanism is consistent with the Cu(II)/Cu(I) redox system. Additionally, the catalytic action of this complex as a new catalyst was evaluated in the synthesis of derivatives of tetrahydropyrimidine by reacting 1,3-propylenediamine with various aryl nitriles under conventional thermal conditions.