Self-Assemblies of Solvates, Ionic Cocrystals, and a Salt Based on 4-{[(4-Nitrophenyl)carbamoyl]amino}-N-(pyrimidin-2-yl)benzene-1-sulfonamide: Study in the Solid and Solution States

Abstract

Solid-state and solution studies were carried out to reveal the interactions of tetrabutylammonium halides with a sulfadiazine-derived urea, namely 4-{[(4-nitrophenyl)carbamoyl]amino}-N-(pyrimidin-2-yl)benzene-1-sulfonamide, influencing the selectivity in the optical detection of fluoride ions in solution. The self-assemblies of two dimethylformamide (DMF) solvates, three ionic cocrystals, and a salt of the sulfadiazine-derived urea were studied. Both solvates had one DMF molecule anchored by bifurcated hydrogen bonds with the urea moiety, whereas the 1:2 solvate had the second DMF in the interstitial spaces. The structures of the three isostructural ionic cocrystals, namely the tetrabutylammonium halide 4-{[(4-nitrophenyl)carbamoyl]amino}-N-(pyrimidin-2-yl)benzene-1-sulfonamide, where halide is chloride, bromide, and iodide, respectively, were determined. However, the corresponding ionic cocrystal was not formed with tetrabutylammonium fluoride; it afforded the salt tetrabutylammonium (4-{[(4-nitrophenyl)carbamoyl]amino}benzene-1-sulfonyl)-(pyrimidin-2-yl)azanide, which was also structurally characterized. Each ionic cocrystal had charge-assisted hydrogen bonds between the respective halide ion and the N−H bonds of the urea moiety. Homodimeric synthons of the parent compound were observed in the ionic cocrystals; hence, the geometrical adjustment of the dimeric synthons due to the slight changes in the angular shape of the host has the prime role of making available room with the required extra space to accommodate the spherical halide ions with different ionic radii. The fluoride, being basic, caused deprotonation to provide the salt. 1 H NMR and UV−visible spectroscopy was used to discern hydrogen bonds formed by the sulfadiazine-based urea with different halides and the deprotonation by tetrabutylammonium fluoride.

Polymorphic solvates, ionic cocrystals and C–N bond formation to form ionic cocrystals in sulfamethoxazole and sulfathiazole-derived urea

“…In a recent study, we presented three different cocrystals with three halides from the same host, with the urea-based host assembling to a hydrogenbonded dimer to provide space for the relatively large quaternary ammonium halides. 3 Similar attempts to prepare ionic cocrystals with different tetrabutylammonium halides (TBAX, X = Cl, Br, I) with HSMZU were not successful here, whereas, as expected the reaction of HSMZU with TBAF yielded the corresponding salt TBA(SMZU). The same crystalline salt was also obtained by a solution of HSMZU with TBABr in DMF at room temperature after several days.…”

“…The cations were held at the two ends of such dimers where the hydrophobic parts were located. The inability of HSMZU to form ionic cocrystals with their original form as compared to the analogous 4-{[(4-nitrophenyl)carbamoyl]amino}- N -(pyrimidin-2-yl)benzene-1-sulfonamide ( H3sulphaurea ) that was reported earlier 3 wsa attributed to the different dimeric synthon in each case. Though the compounds had an L-like shaped geometry, the dimeric synthon of HSMZU was the urea-5-methyl-1,2-oxazole based synthon, which broke down to form hydrogen bonds with a halide (the solution NMR study also supported this, which is discussed separately).…”

“…Self-assemblies of solvates and cocrystals of sulfonamidefunctionalized compounds have a special status due to their utility as active pharmaceutical ingredients. [1][2][3][4][5] Sulfonamide groups have a role in deciding the geometrical feature of their constituent compounds; 6 such a group attached to five or sixmembered heterocycles may adopt either an imine or amine form. [7][8][9] The increasing utility of solvates and cocrystals as well as growing interest in them has been evaluated in the literature [10][11] and suggests their potential in the future.…”

“…34 We recently showed two different solvates possessing one or two solvent/s per host in a urea-based sulfonamide derivative due to the ability of the host to form monomeric and dimeric assemblies. 3 There are examples of urea-based ionic cocrystals having two polymorphs of a hydrate. 35 Beyond the conventional self-assemblies of sulfonamide derivatives 36 as well as of urea derivatives, there is scope to study supramolecular assemblies of those independently or as multiple components.…”

Co-crystals of zwitterionic GABA API's pregabalin and phenibut: properties and application

“…Various definitions for such structures have been proposed. [22][23][24][25][26] As the established terminology has found acceptance in the community, [27][28][29][30] methods to explicitly distinguish between salts and ionic co-crystals were designed. 31,32 Next to varying molecular charges and acidity, a further molecular influence which can impact crystalline structure and lattice makeup is molecular chirality.…”