A copper(II) complex of benzimidazole-based ligand: synthesis, structure, redox aspects and fluorescence properties.

Employing 1-(2-methoxybenzyl)-2-(2-methoxyphenyl)-1H-benzimidazole (bpb) as a monodentate ligand, a new greenish-blue copper(II) complex, [Cu(bpb)2(NO3)2] (1a), has been synthesized.1ahas been characterized analytically and spectroscopically. The X-ray crystal structure of1areveals that it adopts acisdisposition with respect to the ligands. The solid state structure of1ais stabilized by intramolecular offset face-to-faceπ–πstacking. Non-covalent supramolecular edge-to-face C–H⋯πinteractions with neighboring molecules give 1-D supramolecular chains that further lead to the formation of an assembled 3-D supramolecular metal-organic framework via hydrogen bonding interactions.1ashows blue fluorescence most likely due to intramolecular offset face-to-faceπ–πstacking. At room temperature,1ais one-electron paramagnetic. It shows a rhombic EPR spectrum withg1 = 2.12,g2 = 2.42, andg3 = 2.52 in the solid state at liquid nitrogen temperature. In cyclic voltammetry,1adisplays a one-electron oxidative Cu(II)/Cu(III) couple. Our DFT calculations, corroborate the observed experimental results of1a. [ABSTRACT FROM AUTHOR]