A New Zn(II) Azido Complex of L-Arginine: X-ray Crystal Structure, Hirshfeld, and AIM Studies

The synthesis and X-ray crystal structure analyses of the azido complex [Zn(N3)(Arg)2](N3)& BULL;3H2O, where Arg is L-arginine, were presented. The molecular structure of the complex was further studied using FT-IR spectra as well as atoms in molecules (AIM) theory. An analysis of the crystal data indicated monoclinic crystal system and P21 space group with a = 13.0283(5) & ANGS;, b = 15.2032(7) & ANGS;, c = 13.3633(6) & ANGS;, & beta; = 114.3580(10)& DEG;, V = 2411.28(18) & ANGS;3, and Z = 4. Two of the [Zn(N3)(Arg)2](N3)& BULL;3H2O formulae represent the asymmetric unit of this complex where the geometric parameters of both units are slightly different. In [Zn(N3)(Arg)2](N3)& BULL;3H2O, the central Zn(II) ion is penta-coordinated with two Arg molecules as a bidentate ligand and one terminally coordinated azide ion. Each of the two Arg molecules are located trans to one another and coordinated with the Zn(II) via the N and O atoms of the amino and carboxylate groups, respectively. Hence, Zn(II) is five-coordinated and has a distorted square pyramidal coordination geometry. The supramolecular structure of the [Zn(N3)(Arg)2](N3)& BULL;3H2O complex was inspected using the Hirshfeld analysis. The O & BULL;& BULL;& BULL;H (26.6-28.4%), H & BULL;& BULL;& BULL;H (32.3-35.3%), and N & BULL;& BULL;& BULL;H (30.4-34.0%) contacts are the most significant interactions in the crystal structure of the [Zn(N3)(Arg)2](N3)& BULL;3H2O complex. The Zn-N, and Zn-O bonds have slight covalent interactions based on the AIM study.