Crystal structures of three zinc(II) halide coordination complexes with quinoline N-oxide

Clifford W Padgett; Will E Lynch; Erin N Groneck; Melina Raymundo; Desiree Adams

doi:10.1107/S2056989022005953

Crystal structures of three zinc(II) halide coordination complexes with quinoline N-oxide

Acta Crystallogr E Crystallogr Commun. 2022 Jun 10;78(Pt 7):716-721. doi: 10.1107/S2056989022005953. eCollection 2022 Jul 1.

Authors

Clifford W Padgett¹, Will E Lynch¹, Erin N Groneck¹, Melina Raymundo¹, Desiree Adams¹

Affiliation

¹ Georgia Southern University, 11935 Abercorn St., Department of Chemistry and Biochemistry, Savannah GA 31419, USA.

Abstract

The reaction of one equivalent of zinc(II) halide with two equivalents of quinoline N-oxide (QNO) in methanol yields compounds as ZnX ₂(QNO)₂, where X = Cl (I), Br (II) and I (III), namely, di-chlorido-bis-(quinoline N-oxide-κO)zinc(II), [ZnCl₂(C₉H₇NO)₂], di-bromido-bis-(quinoline N-oxide-κO)zinc(II), [ZnBr₂(C₉H₇NO)₂], and di-iodido-bis-(quinoline N-oxide-κO)zinc(II) [ZnI₂(C₉H₇NO)₂]. In all three complexes, Zn cations are coordinated by two QNO ligands bound through the oxygen atoms and two halide atoms, with X-Zn-X bond angles ca 20° wider than the O-Zn-O, giving rise to a distorted tetra-hedral geometry. Crystals of (II) and (III) are isostructural and both show pairwise π-stacking of QNO ligands and weak C-H⋯X hydrogen bonds, while (I) packs differently, with a shorter C-H⋯Cl bond and without π-stacking.

Keywords: Hirshfeld surface analysis; crystal structure; quinoline N-oxide; zinc(II) coordination complex.