Crystal Landscape of Primary Aromatic Thioamides

The crystal landscape of a series of primary aromatic thioamides is described, displaying similar characteristic intermolecular hydrogen-bonding interactions in the solid state to those observed in their widely studied amide analogues, including R₂²(8) dimers and C(4) chains. In a number of cases, high <i>Z</i>′ values were observed in the structures. On the basis of the observed solid-state features, the thioamide functional group, which is a strong hydrogen-bond donor and moderate acceptor, offers considerable potential as a key moiety for crystal engineering

Crystal Landscape of Primary Aromatic Thioamides

The crystal landscape of a series of primary aromatic thioamides is described, displaying similar characteristic intermolecular hydrogen-bonding interactions in the solid state to those observed in their widely studied amide analogues, including R₂²(8) dimers and C(4) chains. In a number of cases, high <i>Z</i>′ values were observed in the structures. On the basis of the observed solid-state features, the thioamide functional group, which is a strong hydrogen-bond donor and moderate acceptor, offers considerable potential as a key moiety for crystal engineering

Investigating CS···I Halogen Bonding for Cocrystallization with Primary Thioamides

Cocrystallization utilizing halogen bonding involving the thiocarbonyl functional group of a series of primary aromatic thioamides has been investigated. The well-known organoiodide 1,4-diiodotetrafluorobenzene was utilized as the halogen bond donor and the CS···I halogen bond was established as a robust supramolecular synthon in these systems. Weak N–H···S hydrogen bonding involving the thioamides influences the overall supramolecular architectures, meaning that there is a diverse range of structural motifs and cocrystal stoichiometries observed. The majority (60%) of the cocrystals obtained have a 2:1 ratio of thioamide/organiodide with the latter present over an inversion center. The higher ratio of organoiodide seen in the other cocrystals is achieved by additional I···I and I···π halogen bonding. The CS···I halogen bond is replaced by N···I halogen bonding in the one cocrystal containing a pyridyl-substituted thioamide. The ability of the thioamides to form cocrystals and the strength of the halogen bond were influenced by the nature of the substituents on the aromatic ring, with derivatives containing electron donating groups most likely to form cocrystals. Calculated molecular electrostatic potential values on the sulfur atom in the thioamides corroborate these experimental results

Utilizing Sulfoxide···Iodine Halogen Bonding for Cocrystallization

The propensity of a range of different sulfoxides and sulfones to cocrystallize with either 1,2- or 1,4-diiodotetrafluorobenzene, via I···O=S halogen bonding, was investigated. Cocrystallization occurred exclusively with 1,4-diiodotetrafluorobenzene in either a 1:1 or 1:2 stoichiometry of the organohalide and the sulfoxide, respectively, depending on the sulfoxide used. It was found that the stoichiometry observed was not necessarily related to whether the oxygen acts as a single halogen bond acceptor or if it is bifurcated; with I···π interactions observed in two of the cocrystals synthesized. Only those cocrystals with a 1:2 stoichiometry exhibit C–H···O hydrogen bonding in addition to I···O=S halogen bonding. Examination of the Cambridge Structural Database shows that (i) the I···O=S interaction is similar to other I···O interactions, and (ii) the I···π interaction is significant, with the distances in the two cocrystals among the shortest known

Utilizing Sulfoxide···Iodine Halogen Bonding for Cocrystallization

The propensity of a range of different sulfoxides and sulfones to cocrystallize with either 1,2- or 1,4-diiodotetrafluorobenzene, via I···O=S halogen bonding, was investigated. Cocrystallization occurred exclusively with 1,4-diiodotetrafluorobenzene in either a 1:1 or 1:2 stoichiometry of the organohalide and the sulfoxide, respectively, depending on the sulfoxide used. It was found that the stoichiometry observed was not necessarily related to whether the oxygen acts as a single halogen bond acceptor or if it is bifurcated; with I···π interactions observed in two of the cocrystals synthesized. Only those cocrystals with a 1:2 stoichiometry exhibit C–H···O hydrogen bonding in addition to I···O=S halogen bonding. Examination of the Cambridge Structural Database shows that (i) the I···O=S interaction is similar to other I···O interactions, and (ii) the I···π interaction is significant, with the distances in the two cocrystals among the shortest known