Crystal structures of two stilbazole derivatives: bis-{(E)-4-[4-(di-ethyl-amino)-styr-yl]-1-methyl-pyridin-1-ium} tetra-iodido-cadmium(II) and (E)-4-[4-(di-ethyl-amino)-styr-yl]-1-methyl-pyridin-1-ium 4-meth-oxy-benzene-sulfonate monohydrate

Acta Crystallogr E Crystallogr Commun. 2018 Nov 30;74(Pt 12):1891-1894. doi: 10.1107/S2056989018016808. eCollection 2018 Dec 1.

Abstract

The title mol-ecular salts, (C18H23N2)2[CdI4], (I), and C18H23N2 +·C7H7O4S-·H2O, (II), are stilbazole, or 4-styryl-pyridine, derivatives. The cation, (E)-4-[4-(di-ethyl-amino)-styr-yl]-1-methyl-pyridin-1-ium, has a methyl group attached to pyridine ring and a diethyl amine group attached to the benzene ring. The asymmetric unit of salt (I), comprises one cationic mol-ecule and half a CdI4 dianion. The Cd atom is situated on a twofold rotation axis and has a slightly distorted tetra-hedral coordination sphere. In (II), the anion consists of a 4-meth-oxy-benzene-sulfonate and it crystallizes as a monohydrate. In both salts, the cations adopt an E configuration with respect to the C=C bond and the pyridine and benzene rings are inclined to each other by 10.7 (4)° in (I) and 4.6 (2)° in (II). In the crystals of both salts, the packing is consolidated by offset π-π stacking inter-actions involving the pyridinium and benzene rings, with centroid-centroid distances of 3.627 (4) Å in (I) and 3.614 (3) Å in (II). In the crystal of (II), a pair of 4-meth-oxy-benzene-sulfonate anions are bridged by Owater-H⋯Osulfonate hydrogen bonds, forming loops with an R 2 4(8) motif. These four-membered units are then linked to the cations by a number of C-H⋯O hydrogen bonds, forming slabs lying parallel to the ab plane.

Keywords: 4-styryl­pyridine derivatives; crystal structure; hydrogen bonding; ring motif; stilbazole; tetra­iodo­cadmate; π-π inter­actions.

Grants and funding

This work was funded by University Grants Commission grant F1–17.1/2017–18/MANF-2017–18-KER-83185 to Priya Antony. Science and Engineering Research Board grant SR/S2/LOP-29/2013.