Synthesis, crystal structure and Hirshfeld analysis of a crystalline compound comprising a 1/1 mixture of 1-[(1R,4S)- and 1-[(1S,4R)-1,7,7-trimethyl-2-oxobicyclo[2.2.1]heptan-3-ylidene]hydrazinecarbothioamide

Abstract

The equimolar reaction between a racemic mixture of (R)- and (S)-camphorquinone with thiosemicarbazide yielded the title compound, C11H17N3OS [common name: (R)- and (S)-camphor thiosemicarbazone], which maintains the chirality of the methylated chiral carbon atoms and crystallizes in the centrosymmetric space group C2/c. There are two molecules in general positions in the asymmetric unit, one of them being the (1R)-camphor thiosemicarbazone isomer and the second the (1S)- isomer. In the crystal, the molecular units are linked by C—H...S, N—H...O and N—H...S interactions, building a tape-like structure parallel to the (\overline{1}01) plane, generating R21(7) and R22(8) graph-set motifs for the H...S interactions. The Hirshfeld surface analysis indicates that the major contributions for crystal cohesion are from H...H (55.00%), H...S (22.00%), H...N (8.90%) and H...O (8.40%) interactions.

Keywords

• chiral thiosemicarbazone
• camphor derivative
• racemic mixture
• crystal structure