13464-58-9Relevant academic research and scientific papers
Structural and electronic evolution of the As(OH)3 molecule in high temperature aqueous solutions: An x-ray absorption investigation
Testemale, Denis,Hazemann, Jean-Louis,Pokrovski, Gleb S.,Joly, Yves,Roux, Jacques,Argoud, Roger,Geaymond, Olivier
, p. 8973 - 8982 (2004)
The geometrical and electronic structure of the arsenious acid molecule As(OH)3 in aqueous solutions has been investigated by x-ray absorption spectroscopy (XAS) within extended x-ray absorption spectroscopy (EXAFS) and x-ray absorption near edge structure (XANES), using realistic first-principle calculations in the latter case. This investigation was performed on aqueous solutions of arsenious acid from ambient to supercritical conditions (P = 250 and 600 bars, T ≤500°C) using a new optical cell. The analysis of the XAS spectra is consistent with (1) a constant As-O distance, (2) an opening of the O-As-O angles within the C3V pyramidal structure in the range 30-200°C. This structural evolution comes along with a small decrease of the partial charges of the atoms in the As(OH)3 molecule. The explanation invoked for both structural and electronic modifications observed is the weakening of the interactions, through hydrogen bonds, between the As(OH)3 complex and water molecules. This is a fingerprint of the similar weakening of hydrogen bonding interactions in the solvent itself.
Kinetic Studies of the Oxidation Reaction of Arsenic(III) to Arsenic(V) by Peroxodisulphate Ion in Aqueous Alkaline Media
Nishida, Suzuko,Kimura, Masaru
, p. 357 - 360 (1989)
The arsenic(III) ion was oxidized to arsenic(V) by the peroxodisulphate ion in aqueous alkaline solutions of various pH (>8.6) at 20-40 deg C.The only reactive species at pH 8.6-11.6 was the deprotonated species H2AsO3(1-); the mechanisms (i) and the rate law (iii) are proposed to (i) (ii) (iii) account for the results obtained.The first acid dissociation constant Ka of H3AsO3 and the rate constant k for the reaction between the S2O8(2-) and H2AsO3(1-) ions were determined under various conditions.The activation enthalpy and entropy, ΔH and ΔS, for the reaction of H2AsO3(1-) with S2O8(2-) were 47.6 kJ mol-1 and -130.4 J K-1 mol-1, respectively, whereas ΔHa and ΔSa for the acid dissociation of H3AsO3 were 2.8 kJ mol-1 and -117.4 J K-1 mol-1, respectively.The addition of acrylamide and acrylonitrile as radical scavengers produced no polymer and did not affect the reaction rate.The radicals SO4.(1-) and As(IV), the expected reaction intermediates, could not be detected by the addition of acrylamide and acrylonitrile monomers, and thus, the reaction between S2O8(2-) and As(III) is considered to be a two-electron transfer reaction.In strong basic medium (pH12.0), the HAsO3(2-) ion as well as H2AsO3(1-) reacted with the peroxodisulphate ion with the rate constant (1.6+/-0.3)*10-2 dm3 mol-1 s-1 at an ionic strenght of 0.1 mol dm-3, at 30 deg C.
Synthesis and crystal structure of a solvate of arsenic 4,6-dimethyl-8-quinolinethiolate
Silina,Belyakov,Ashaks,Pech,Zaruma
, p. 1544 - 1550 (2012)
A crystallosolvate of arsenic 4,6-dimethyl-8-quinolinethiolate, As[4,6-Me2C9H4NS]3·CHCl3 has been synthesized. The molecular and crystalline structures of the compound have been determined by X-ray structural analysis. The influence of the composition and structure of the ligand on the geometry of the coordination environment of the central arsenic atom in the investigated crystal structures of intracomplex compounds of 8-quinolinethiols is discussed. Grant: The authors are grateful to the Latvian Council of Science for financial support of the investigation.
Influence of pressure in the 0.1-100 MPa interval on the first dissociation constant of arsenous acid in water solutions at 298.15 K
Shikina,Zotov,Tagirov
, p. 1076 - 1078 (2010)
The influence of pressure on the dissociation of arsenous acid H 3AsO3 was studied at 298.15 K by the potentiometric method. In the pressure interval from 0.1 to 100 MPa the values of log K 1 = -9.32 + 0.00246P.
Chemical reactions in electric pulse dispersion of iron in aqueous solutions
Danilenko,Savel'ev,Yavorovskii,Yurmazova
, p. 803 - 809 (2008/09/21)
IR spectroscopy, X-ray phase, chemical, kinetic, and thermodynamic analyses were used to determine the nature of chemical reactions occurring in electric pulse dispersion of a metal (Fe) in aqueous solutions of inorganic substances (MnSO4, NaH2AsO4, H3AsO3, K2Cr2O7).
Oxidation of Arsine by a Heteropolyacid in the Presence of Halide Ions
Dorfman, Ya. A.,Aleshkova, M. M.,Doroshkevich, D. M.,Kel'man, I. V.
, p. 1805 - 1807 (2007/10/02)
The kinetics and mechanism of the oxidation of arsine by a heteropolyacid have been investigated in the presence of halide ions as the catalyst.It has been established that thenrate-limiting stage in the proposed mechanism is the inner-sphere oxidation of arsine in the intermediate vanadium(V) complex with AsH3 and the halide ion.A quantuum-chemical calculation of the electronic structure of the intermediate complexes has been carried out and the results support the proposed mechanism.A method for the theoretical estimation of the activation energy is put forward.
