The isolation and structure of a highly stable, metallation-resistant and multiply hydrogen-bonded sulfonylamide–phosphine oxide adduct, PhSO2CH2C(O)NH2·OP(NMe2)3, PSA·HMPA (PSA = phenylsulfonylacetamide, HMPA = hexamethylphosphoramide)

Abstract

Attempted metallations of the expectedly acidic sulfonylamide (PSA) in the presence of the phosphine oxide HMPA all fail, giving instead the very stable 1:1 adduct PSA·HMPA; its solid-state structure consists of layers of PSA molecules linked by intercalated HMPA molecules, such aggregation resulting in particular from a large number of significant C–H ⋯ O hydrogen-bonding interactions per PSA·HMPA unit.