Interplay of O–H⋯O, C–H⋯O and carbonyl–carbonyl interactions in crystal structures of o-benzoyl-l-tartaric acid and its anhydride

Molecular and crystal structures of monobenzoyl tartaric acid (1) and its anhydride (2) were determined and analyzed. The molecule of 1 adopts the trans(syn,syn) conformation. In the molecule of 2 the anhydride five-membered ring shows approximate C2 symmetry with the twisted conformation. Crystal structure analysis supported with the Hirshfeld surface fingerprint plots enabled the identification of the significant intermolecular interactions. The 1-D supramolecular assemblies of p21 rod group symmetry are formed by intermolecular O–H⋯O hydrogen bonds in 1, while in case of 2 via O–H⋯O bonds supported by the orthogonal carbonyl–carbonyl and C–H⋯O interactions. Further the 2-D structures of p2111 layer group symmetry are constructed through O–H⋯O and C–H⋯O bonds in 1 and 2, respectively. Weaker C–H⋯O and C–H⋯π interactions join the layers into 3-D structures. Detailed analysis showed that the conformation of 1 results from strong intermolecular interactions.