Hydrogen bonding in 4-carboxyanilinium dihydrogenphosphate

Abstract

The crystal structure analysis of the title compound, C7H8NO2+·H2PO4−, has revealed a three‐dimensional hydrogen‐bonded network structure, involving the dihydrogenphosphate anions, the carboxyl groups and the ammonium groups. The anions are held together via strong O—H...O hydrogen bonds. In addition to the N—H...O and O—H...O interactions, involving all the H atoms covalently bonded to the anion, the nitrogen and the carboxyl group, the crystal structure is also stabilized by C—H...O and C—H...π short contacts.

4-Carboxyanilinium dihydrogen phosphate monohydrate, an organophosphate adducts of 4-amino benzoic acid: Structural, vibrational, thermal, and computational studies

“…The O-P-O bond angles of H2PO4anions are in the range 106.04(8)° to 115.05(9)°. These lengths and angles of the bonds are in good agreement with those observed in similar compounds [7,8].…”

“…The clear solution obtained by dissolving the ingredient was left undisturbed at 20 °C. Most of the time, first 4-carboxyanilinium dihydrogen phosphate (4-CAH2PO4) crystals were obtained [8]. The 4-CAH2PO4 crystals were removed by filtering and the remaining solution was left undisturbed.…”

“…4-Carboxyanilinium dihydrogen phosphate monohydrate (4-CAH2PO4•H2O) and 4-carboxyanilinium dihydrogen phosphate (4-CAH2PO4) (Figure 3) [8] both are organo-phosphate adducts of 4-amino benzoic acid. However, the crystal structure of 4-CAH2PO4•H2O is different from that of 4-CAH2PO4.…”

“…Benali-Cherif et al [7,8] has reported the crystal structure of p-carboxyphenylammonium dihydrogenmonophosphate monohydrate and 4-carboxyanilinium dihydrogen phosphate, respectively. 4-Carboxyanilinium dihydrogen phosphate (4-CAH2PO4) crystalizes in space group monoclinic, P21/n, Z = 4 and the asymmetric unit contains one 4-carboxyanilinium cation and one dihydrogen phosphate anion [8]. In the crystal structure, each p-carboxyanilinium cation is connected to five dihydrogen monophosphate anions via hydrogen bonds.…”

Vibrational study and thermal behavior of dihydrogenotriphosphate trihydrate of 4-aminobenzoic acid and its anhydrous new form fertilizer type NP

“…The active sites of several biological systems have kind of hydrogen bonding in hybrid compound 2 . Indeed, the crystal structures of 4-carboxyphenylammonium dihydrogen phosphate and 4-carboxyanilinium hydrogen sulphate compounds have been recently studied 3,4 . Furtherer, the p-carboxyphenylammonium dihydrogen-monophosphate monohydrate compound was found to consist of H2PO4anions, water molecules and p-HOOC-C6H4-NH3 + cations 5 .…”