LAUSR

Abstract The evaluation of 2-phenylbenzimidazole (LI) and 2-(2-iodophenyl)-5-chlorobenzimidazole (LII) as basic ligand precursors in the synthesis of novel copper(II) acetate structures is described. A reaction of Cu(OAc)2 with LI and LII in aqueous alcoholic solution in the presence of acetic acid leads to heteroleptic mononuclear complexes [Cu(OAc)2LI2] (1) and [Cu(OAc)2LII2]·2AcOH (2·2AcOH), respectively. According to single-crystal X-ray diffraction and FTIR spectroscopy, a monodentate and an anisobidentate coordination mode of the OAc− anion was established in 1 and 2·2AcOH, respectively. The structures of both 1 and 2·2AcOH are stabilized by classic intermolecular H-bonds yielding a simplified underlying network with the uninodal 4-connected topology sql/Shubnikov tetragonal plane net and with the binodal 2,4-connected topology 2,4L2, respectively. The former structure also contains intermolecular π⋯π stacking interactions. LI was found to be emissive in the solid state at room temperature with the emission band centered at 420 nm due to intraligand π* → π and π* → n transitions. The CIE chromaticity diagram quantified the blue color of the emission.