Anion-π interactions in layered structures of salts of 5-(hydroxyimino) quinolin-8-one and related salts

2019

ACS Omega

The cocrystals of sulfamethazine with different acids, namely, 2-mercaptophenylcarboxylic acid, 2,6-pyridinedicarboxylic acid, 4-(4-hydroxyphenylazo)phenylcarboxylic acid, 3-(4-hydroxyphenyl)propanoic acid, and 4-(phenyl)phenylcarboxylic acid, are studied here. Each has distinct notable supramolecular features. The pyrimidin-2-amine unit of the sulfamethazine provided unique examples of cocrystals in which amidine and imidine forms or neutral and protonated forms of sulfamethazine are observed in 2:2 ratios. Hence, this study provides avenues to explore cocrystals with tautomeric forms together in a cocrystal and also neutral and protonated cocrystal partners as apparent multicomponents in cocrystals. Among the cocrystals, three of them have the amidine form of the sulfamethazine in respective self-assembly. The cocrystal of 2-mercapto-phenylcarboxylic acid with sulfamethazine has the amidine form and it has the distinction of having S–H···π interactions. The cocrystal of sulfamethazine with 2,6-pyridinecarboxylic acid is a rare example of a 1:1 cocrystal of sulfmethazine with dicarboxylic acid. It has methanol molecules as a solvent of crystallization. Sulfamethazine forms a hydrated cocrystal with 4-(4-hydroxyphenylazo)-phenylcarboxylic acid that has conventional R 2 2 (8) synthons of amidine hydrogen-bonding with carboxylic acid. The phenolic part of the acid component is anchored to the water molecule and provides a robust self-assembly. The hydrated cocrystal of sulfamethazine with 3-(4-hydroxyphenyl)propanoic acid (2:2 cocrystal) has two independent molecules of sulfamethazine, one in amidine form and the other in imidine form. It has two neutral carboxylic acids anchored through complementary hydrogen bonds and also has two water molecules of crystallization. The cocrystal of sulfamethazine with 4-(phenyl)phenylcarboxylic acid is also a 2:2 cocrystal. It is a di-hydrate, which has a neutral and protonated form of sulfamethazine. The neutral form is hydrogen-bonded to a neutral carboxylic acid, whereas the protonated form is charge-assisted hydrogen-bonded to the corresponding carboxylate anion.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Combinations of Tautomeric Forms and Neutral-Cationic Forms in the Cocrystals of Sulfamethazine with Carboxylic Acids

Singh

2019

ACS Omega

“…Among the weak interactions, π-interactions such as π-stacking, − C–H···π interactions, , N–H···π, O–H···π, anion-π interactions, − and cation-π interactions , are of prime concern in crystal engineering. Aromatic-imide derivatives are useful to study different π-stacking interactions, − and the impact imparted by such interactions greatly affects the photoluminescence properties of fluorphores in solids. − The progress of aggregation induced emissions in solids has made the emission properties of solids very interesting. − The conformations guided by a substituent contributing to twisted intramolecular charge transfer in aggregates have made significant progress to tune fluorescence emission in self-assembled systems. − Scientists from different backgrounds are focusing attention on tuning signal transductions of naphthalimide derivatives due to their ease in handling and available literature .…”

Section: Introductionmentioning

confidence: 99%

Changing π-Interactions and Conformational Adjustments of N-(Isonicotinylhydrazide)-1,8-naphthalimide by Hydration and Complexation Affect Photophysical Properties

Tarai

Crystal Growth & Design

2017

Noncovalent self-assemblies of different forms of a 1,8-naphthalimide derivative N-(isonicotinylhydrazide)-1,8-naphthalimide adopt different conformational adjustments due to the interplay of weak interactions. In such assemblies stacking interactions significantly contribute to direct the orientations of tether, which also influenced packing patterns. Effects of weak noncovalent interactions are reflected in the physicochemical properties of solvate and metal complexes of this naphthalimide derivative. Dual fluorescence emissions were observed from hydrate and silver complex of N-(isonicotinylhydrazide)-1,8-naphthalimide, which was not observed in anhydrous form of the compound. These results are compared with fluorescence emission study performed with solution of N-(isonicotinylhydrazide)-1,8-naphthalimide. Aggregation induced fluorescence emission of a solution in DMSO was caused by adding water. This emission in solution occurred at a much different emission wavelength than the emission observed from the hydrated sample in the solid state. It is also established that the aggregation induced fluorescence of N-(isonicotinylhydrazide)-1,8-naphthalimide caused by adding water to a solution of the compound in dimethyl sulfoxide can be quenched by different nitro-phenols.

Tetranuclear Cobalt Complexes as Nano-Dimensional Template for Inclusion of Nitrophenols

Shankar

2016

ChemistrySelect

Htea = dianion of triethanolamine, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline) having tetranuclear cations with end to end distance~1.69 nm and~1.62 nm respectively were characterized. These complexes are weakly fluorescent in sol-ution and fluorescence of respective complexes decreases upon interactions with nitrophenols. Complexes from reactions of 1 and 2 with nitrophenols were isolated and structurally characterized. They also show lower fluorescence in solid state than respective parent complex due to oxygen-p interactions. Complex 2 underwent cation exchange to form new tetranuclear oxido cobalt complexes possessing [MCl 4 ] 2À ( M= Zn or Cd) anion.