title: 2,5-Diaryl-1,3,4-selenadiazoles prepared from Woollins' reagent.
abstract: Two polymorphs of 2,5-diphenyl-1,3,4-selenadiazole, C(14)H(10)N(2)Se, denoted (Ia) and (Ib), and a new polymorph of 2,5-bis(thiophen-2-yl)-1,3,4-selenadiazole, C(10)H(6)N(2)S(2)Se, (IIb), form on crystallization of the compounds, prepared using Woollins' reagent (2,4-diphenyl-1,3-diselenadiphosphetane 2,4-diselenide). These compounds, along with 2-(4-chlorophenyl)-5-phenyl-1,3,4-selenadiazole, C(14)H(9)ClN(2)Se, (III), and 2-(furan-2-yl)-5-(p-tolyl)-1,3,4-selenadiazole, C(13)H(10)N(2)OSe, (IV), show similar intermolecular interactions, with π-π stacking, C-H...π interactions and weak hydrogen bonds typically giving rise to molecular chains. However, the combination of interactions differs in each case, giving rise to different packing arrangements. In polymorph (Ib), the molecule lies across a crystallographic twofold rotation axis, and (IV) has two independent molecules in the asymmetric unit.
authors.affiliation: School of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland.
authors.forename: David B
authors.initials: DB
authors.lastname: Cordes
authors.forename: Guoxiong
authors.initials: G
authors.lastname: Hua
authors.forename: Alexandra M Z
authors.initials: AM
authors.lastname: Slawin
authors.forename: J Derek
authors.initials: JD
authors.lastname: Woollins