Co-crystallization experiments of thiocarbamides with bipyridine-type molecules

Crystal structure of the co-crystal O-isopropyl phenylcarbamothioate – 4,4′-bipyridine (2/1), C15H17N2OS

“…The strictly planar 4,4′-bipyridyl molecule is situated about a centre of inversion with the unlabelled atoms of the figure related by the symmetry operation: 1 − x, −1 − y, 1 − z. The three-molecule aggregate resembles that observed in the previously reported 2:1 co-crystal of the title carbothioamide with trans-1,2-bis(4-pyridyl)ethene [8]. Indeed, all known co-crystals of this type, i.e.…”

“…The syn disposition of the thioamide-N-H and thione-S atoms is consistent with that observed in the three other known structures containing the identical i-PrOC(=S)N(H)Ph molecule. An overlap diagram (not shown) of the molecule reported herein, the parent compound [5], the molecule in the 2:1 cocrystal with trans-1,2-bis(4-pyridyl)ethene [8] and that with the thione-S coordinating a (Ph 3 P) 2 CuCl entity [9] shows a remarkable consistency of conformation. The major difference arises, in fact, for the i-Pr group in the title compound which is rotated about the O-C axis by approximately 60°compared to the three literature molecules.…”

“…molecules of the general formula ROC(=S)N(H)R′ for R, R′ = alkyl/aryl [6], find interest in crystal engineering endeavours in terms of their ability to form thioamide-N-H· · · S(thione) hydrogen bonds and the influence of this upon molecular conformation [5][6][7] as well as their propensity to form co-crystals [8]. As a continuation of the latter studies, the title 2:1 co-crystal was isolated.…”

“…Indeed, all known co-crystals of this type, i.e. [ROC(=S)N(H)R′] 2 (bipyridyl-type molecule), six in all, feature a similarly assembled three-molecule aggregate [8]. The syn disposition of the thioamide-N-H and thione-S atoms is consistent with that observed in the three other known structures containing the identical i-PrOC(=S)N(H)Ph molecule.…”

“…The major difference arises, in fact, for the i-Pr group in the title compound which is rotated about the O-C axis by approximately 60°compared to the three literature molecules. The dihedral angles between the central CNOS residue and appended N-bound phenyl ring vary from apprimxately 28°in the copper(I) complex [9] to 47°in the co-crystal [8].…”