Synthesis and structure of tetraphenylphosphonium carboxylates [Ph4P][OC(O)C6H3(OH)2-2,6], [Ph4P][OC(O)Ch2Ch2C(O)OH]

Tetraphenylantimony 2,6-dihydroxybenzoate benzene solvate (1) and hydrogen succinate (2) were obtained by the interaction between pentaphenylphosphorus (0.5 mol benzene solvate) with dihydroxybenzoic and succinic acids at room temperature in benzene solution. The compounds have been characterized by IR-spectroscopy and X-ray analysis. The absorption bands of the carbonyl groups are present in the IR-spectra, recorded on a Shimadzu IRAffinity-1SIR-Fourier spectrometer in the 4000-400 cm-1 area in KBr pellets, at the 1637 cm-1 frequency. According to the X-ray analysis, carried out on a D8 QUEST Bruker diffractometer, the compound unit cell parameters are: triclinic syngony, P 1 (1 ) , P212121 (2) symmetry group; а 10.914(6) (1), 7.762(6) (2), b 13.701(9) (1), 13.986(9) (2), c 19.661(12) (1), 22.046(14) (2) Å, α 99.53(3)° (1), 90.00° (2), β 105.226(16)° (1), 90.00° (2), γ 91.70(2)° (1), 90.00° (2), V 2789(3) (1), 2393(3) (2) Å3. The crystals of tetraphenylphosphonium carboxylates consist of the tetrahedral tetraphenylphosphonium cations and single-charged carboxylate anions. The valence angles in tetraphenylphosphonium cations equal 107.75(10)-112.88(10)°, 106.30(10)-113.77(10)° (1) and 107.72(17)-110.65(17)° (2). The P-C distances equal 1.783(2)-1.799(2) Å (1) and 1.793(4)-1.799(4) Å (2). The structural organization of the crystals is due to the weak interionic СPh-Н···О-type hydrogen bonds with the involvement of the carboxylate groups. In the case of tetraphenylphosphonium 2,6-dihydroxybenzoate benzene solvate the СPh-Н···О hydrogen bonds with the involvement of the hydrogen atom of the benzene solvating molecule are also observed.