Preparation of salts of the 5,5′-(1,4-phenylene)bis(1,3,2,4-dithiadiazolylium) dication and of its 1,2- and 1,3-phenylene analogues. Preparation and crystal structure of the stacked, neutral 5,5′-(1,4-phenylene)bis(1,3,2,4-dithiadiazole)

Abstract

Reactions of o-, m- and p-C₆H₄(CN)₂ with [SNS][AsF₆] in liquid SO₂ produced the AsF₆^– salts of o-, m- and p-[C₆H₄([graphic omitted])₂]²⁺ in high yield. The para-phenylene AsF₆^– salt was readily converted (>75%) into other salts (Cl^–, Br^–, SbCl₆^– or S₃N₃^–) by anion metathesis. Reduction of [p-C₆H₄-([graphic omitted])₂]Cl₂ with SbPh₃ gave the bis(dithiadiazole), p-C₆H₄([graphic omitted])₂, which crystallises in the triclinic space group P, with a= 5.772(1), b= 6.382(1)c= 7.491(1)Å, α= 79.21(1), β= 82.86(1), γ= 70.25(1)°, Z= 1; R= 0.077 for 678 observed reflections. The structure shows equidistant molecular stacking of the trans isomer with weak S ⋯ S (3.214 Å) and S ⋯ N (3.346 Å) intermolecular interactions.