Supramolecular aggregation in dithia-arsoles: chlorides, cations and N-centred paddlewheelsElectronic supplementary information (ESI) available. CCDC 1546788-1546793. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7ce01117b

The benzo-fused dithia-chloro-arsole derivative C 6 H 4 S 2 AsCl ( 1 ) is found to crystallise in the triclinic space group P 1&cmb.macr; with 17 molecules in the asymmetric unit whereas the tolyl derivative, MeC 6 H 3 S 2 AsCl ( 2 ) is polymorphic with the α-phase crystallising in the monoclinic space group P 2 1 / c with a single molecule in the asymmetric unit and the β-phase adopting a triclinic structure with two molecules in the asymmetric unit. Reaction of these dithia-chloro-arsole derivatives with LiN(SiMe 3 ) 2 in a 3 : 1 mole ratio afforded the unique paddlewheel structure (MeC 6 H 4 S 2 As) 3 N ( 4 ). New isomorphs and chain-like motifs with an astounding 17 molecules in the asymmetric unit of dithia-chloro-arsoles are described in addition to novel paddlewheel structures.