Polysulfonylamines, CLXXXII [1]. Bis(triphenylphosphoranylidene)ammonium di(4-fluorobenzenesulfonyl)amide: Two polymorphs featuring different conformations of the cation and the anion

Abstract

Two polymorphs A and B of the previously unreported compound [Ph3PNPPh3](+)[(4-F-C6H4SO2)(2)N](-) have been revealed by serendipity (form A: triclinic, space group P (1) over bar, Z' = 1; form B: monoclinic, space group P2(1) In, Z' = 1). Conformational flexibility of both the cation and the anion appears to facilitate polymorph formation. The (C3P)(2)N moiety of the cation, as viewed down P... P, is ecliptic in A but staggered in B, whereas the extended conformations of the anion (C-S... S'-C' antiperiplanar) display notably different torsion angles about the S-N and the S-C bonds. Each structure is characterized by an extensive network of weak C-H... O/N/F hydrogen bonds and CH/pi interactions. The packing of A consists of cation monolayers that intercalate parallel chains of anions. In contrast, polymorph B forms homoionic strands, whereby each strand comprises two ion chains and is surrounded by four parallel strands of opposite charge.