Patterns of soft C-H center dot center dot center dot O hydrogen bonding in diaryl sulfones

In bis(4-tolyl) sulfone, C14H14O2S (1) 2,5,4'-trimethyldiphenyl sulfone, C15H16O2S (2), and 4-chlorodiphenyl sulfone, C12H9ClO2S (3), the molecules are linked by soft C-H . . .O hydrogen bonds into three different types of one-dimensional aggregate: simple chains in (1), molecular ladders in (2) and chains of fused rings in (3). In each of 3,4-dimethyl-4'-chlorodiphenyl sulfone, C14H13ClO2S (4), and 2,5-dimethyldiphenyl sulfone, C14H14O2S (5), the C-H . . .O hydrogen bonds link the molecules into two different types of two-dimensional sheet, based on a (4,4) net in (4) and a (3,6) net in (5). The patterns of soft C-H . . .O hydrogen bonds in (1)-(5) are compared with those in other diaryl sulfones, mainly retrieved from the Cambridge Structural Database, whose substitution patterns preclude the formation of hard hydrogen bonds. Observed aggregation modes range from the formation of no C-H . . .O hydrogen bonds at all, via finite (zero-dimensional) arrays through one-, two- and three-dimensional systems.