Sugar-aza-crown ether-based cavitand 1 can act as a selective turn-on fluorescence sensor for hydrogen sulfate ion in methanol among a series of tested anions. Spectroscopic studies, particularly NMR spectroscopy, revealed that the C-H hydrogen bonding between 1,2,3-triazole ring of cavitand 1 and hydrogen sulfate ion is crucial for the high selectivity of the receptor for hydrogen sulfate.

The asymmetric unit of the title compound, C(6)H(8)N(+)·HSO(4) (-), contains two cations and two anions which are linked to each other through N-H⋯O hydrogen bonds, formed by all H atoms covalently bonded to the N atoms. In addition, strong O-H⋯O anion-anion hydrogen-bond inter-actions are also observed.

In the crystal structure of the title compound, C(4)H(6)N(3) (+)·HSO(4) (-), hydrogen sulfate anions self-assemble through O-H⋯O hydrogen bonds, forming chains along the b axis, while the cations form centrosymmetric pairs via N-H⋯N hydrogen bonds. The 2-amino-pyrimidinium pairs are linked to the sulfate anions via N-H⋯O hydrogen bonds, forming a two-dimensional network parallel to (10[Formula:...

Alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1H)-ones in high yields at 80 °C. Our results showed that Biginelli reaction not only is pH dependent, but the cation of catalyst plays an importan...

The title salt, C(8)H(11)N(2)O(+)·HSO(4) (-), has been synthesized by the reaction between 4-meth-oxy-benzamidine and sulfuric acid. The asymmetric unit comprises a nonplanar 4-meth-oxy-benzamidinium cation and one hydrogen sulfate anion. In the cation, the amidinium group has two identical C-N bonds [1.306 (2) and 1.308 (2) Å], and its plane forms a dihedral angle of 6.49 (8)° with the mean pl...

The crystal structure of the title compound, C(7)H(8)NO(+)·HSO(4) (-), consists of O-H⋯Ohydrogen-bonded extended chains of hydrogen sulfate anions. Each hydrogen sulfate anion is furthermore connected to one 4-acetyl-pyridinium cation via a hydrogen bond of the N-H⋯O type.

In this research, we have developed cheap recyclable and task-specific acidic ionic liquids (AILs) 1-hydrogen-3-methylimidazolium hydrogen sulfate [Hmim]HSO4, 1-hydrogen-3-methylimidazolium chloride [Hmim]Cl, 2-pyrrolidonium hydrogensulfate [Hnhp]HSO4 and applied them in acid catalyzed synthesis of quinoxaline derivatives from 1,2-phenylendiamines and 1,2-dicarbonyl compounds. The products coul...

The crystal structure of the title compound, C(6)H(6)NO(2) (+)·HSO(4) (-), is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds.

The crystal structure of the title salt, C(5)H(6)NO(+)·HSO(4) (-), consists of planar(r.m.s. deviation = 0.001 Å) 4-hydroxy-pyridinium cations and hydrogen sulfate anions which are hydrogen bonded into a layer motif. In the anion, the S-O bond [1.551 (2) Å] involving the O atom bearing the acid H atom is longer than the other three S-O bonds, which range from 1.437 (1) to 1.454 (1) Å.