Synthesis and crystal structure of 1,2,3,4-tetrahydro-9-aminoacridine tetrachlorozincate(II) monohydrate

Abstract

In the reaction of ZnCl2 with tacrine hydrochloride in water novel tetracoordinated (C13H15N2)2[ZnCl4].H2O complex has been obtained and characterized by elemental analysis, molar conductivity and X-ray analysis. The structure contains two crystallographically different molecules of protonated tacrine present as counter cations, [ZnCl4]2- complex anion and one water solvent molecule. The counter cations slightly differ in puckering of the cyclohexenyl ring. The molecules of protonated tacrine are involved in different intermolecular hydrogen bonds. The π–π stacking interactions between the rings of protonated tacrine have been evidenced in the crystal. The [ZnCl4]2- complex anion has distorted tetrahedral geometry. Three out of four Cl atoms are involved in intermolecular hydrogen bonds. Intermolecular H-bond interactions that involve Cl atoms affect the Zn-Cl bond lengths.