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, C1 5H16O2S (2), and 4-chlorodiphenyl sulfone, C12H9ClO2S (3), the molecules ar e linked by soft C-H . . .O hydrogen bonds into three different types of on e-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 su lfone, C14H13ClO2S (4), and 2,5-dimethyldiphenyl sulfone, C14H14O2S (5), th e 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 Struct ural Database, whose substitution patterns preclude the formation of hard h ydrogen bonds. Observed aggregation modes range from the formation of no C- H . . .O hydrogen bonds at all, via finite (zero-dimensional) arrays throug h one-, two- and three-dimensional systems.