Secondary bonding as a force dictating structure and solid-state aggregation of the primary nitrene sources (arylsulfonylimino)iodoarenes (ArINSO2Ar')

Iodonium ylides of the form ArINSO2Ar' (Ar = m-tolyl, Ar' = p-nitrophenyl (1); Ar = m-tolyl, Ar' = phenyl (2); Ar = m-tolyl, Ar' = p-tolyl (3); Ar, Ar' = p-tolyl (4)) have been prepared and crystallographically characterized. Comparisons to previously structurally characterized members of this class of materials (PhINTs (Ts = p-toluenesulfonyl), a-TolylINTs, MesINTs) demonstrate that apparently minor perturbations of the aromatic rings have substantial consequences on the supramolecular assemblies of these materials. The structures range from zig-zag polymers (PhINTs, MesINTs), linear polymers (o-TolylINTs), layered structures (BI, two-dimensional ladders (2, 3, o-TolylINTs), to even three-dimensional stepladders (4). Ab initio calculations for a model molecule, PhINSO2-Ph, corroborate the presence of a I-N single band and show considerable charges being localized on the I, N, S, and O atoms (+, -, +, and - charges, respectively). Extensive attractive networks of I ... O and I ... N secondary bonds thus dominate the solid-state polymers. Within the monomeric units of ArINSO2Ar', a U-turn-shaped motif is observed. This structural shape appears to optimize secondary bonding contacts between charged INSO2 arrays. The structures of ArINSO2Ar' have been systematically characterized.