Cyclic C–H⋯O motifs as general supramolecular synthon in aromatic sulfonester trimers

Abstract The synthesis, analytical characterisation and four X-ray structures of aromatic sulfonester trimers featuring a meta-substitution are reported. The title compounds feature either resorcinol or a 1,3-benzenedisulfonyl moiety as a central unit; one of the trimers exists in two polymorphic forms. Depending on the Caryl-SO2-O-Caryl torsion angles two main conformations have been detected: U- and W-shape. Only little influenced by the molecular conformation the prevailing non-covalent interaction in the packing of all four title structures are C–H⋯O contacts. Thereby, aromatic H atoms in ortho position to oxysulfonyl groups serve as hydrogen bonding donor and S O units as hydrogen bonding acceptors. In all cases the structures contain cyclic supramolecular synthons featurin R 2 2 ( 10 ) g either graph- R 2 2 ( 12 ) set descriptor for the resorcinol trimers and for benzenedisulfonic acid derivatives respectively. One of the two supramolecular synthons is also present in most published sulfontriester X-ray structures uninfluenced from the aromatic substitution pattern.