Supramolecular Architecture in a Ni(II) Complex with a Weakly Bonded N,N′-(1,4-phenylenedi- carbonyl)Diglycinate Counter-Anion: Crystal Structure Investigation and Hirshfeld Surface Analysis

Abstract

In this work, we describe the structural investigation of a Ni(II) complex, [Ni(C12H8N2)2(H2O)2]2·(C12H10N2O6)·(NO3)2·10H2O, with phenanthroline ligands, a deprotonated aromatic dicarboxylic acid, N,N′-(1,4-phenylenedicarbonyl)diglycine, and a nitrate as counter-anions, as well as water molecules. Noncovalent interactions, such as π–π stacking, lone-pair···π, and C–H···π between the phenanthrolines of the cationic complex, [Ni(C12H8N2)2(H2O)2]2+, and counter-anions are observed. Moreover, the solvated and noncoordinating counter-anion, N,N′-(1,4-phenylenedicarbonyl)diglycinate, is embedded in classical and nonclassical hydrogen-bonding interactions with water molecules and phenanthrolines. The two water molecules coordinated by the NiII atom and hydrogen bonded to the carboxylate of the N,N′-(1,4-phenylenedicarbonyl)diglycinate show attractive secondary electrostatic interactions, and a DD/AA hydrogen bonding pattern is formed. The noncovalent interactions of the cationic complex and the solvated N,N′-(1,4-phenylenedicarbonyl)diglycinate counter anion were explored with a Hirshfeld surface analysis, and related contributions to crystal cohesion were determined. The results of the N,N′-(1,4-phenylenedicarbonyl)diglycinate counter anion were compared to those of a solvated N,N′-(1,4-phenylenedicarbonyl)diglycine molecule of a previously described copper(II) complex.