Experimental and theoretical vibrational spectroscopic evaluation of arsenate coordination in aqueous solutions, solids, and at mineral-water interfaces

Journal Article · Thu Oct 01 04:00:00 EDT 1998 · Geochimica et Cosmochimica Acta

DOI:https://doi.org/10.1016/S0016-7037(98)00222-1· OSTI ID:338613

Myneni, S C.B.; Traina, S J; Logan, T J ^[1]; Waychunas, G A ^[2]

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1. Ohio State Univ., Columbus, OH (United States). School of Natural Resources
2. Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

Arsenate (AsO{sub 4}{sup 3{minus}}) is a common species in oxidizing aquatic systems and hydrothermal fluids, and its solubility and partitioning into different mineral phases are determined by the nature of AsO{sub 4}{sup 3{minus}} coordination, solution pH, type of soluble cations, and H{sub 2}O structure at the mineral-fluid interfaces. While the vibrational spectroscopy has been widely used in examining the AsO{sub 4}{sup 3{minus}} coordination chemistry, insufficient knowledge on the correlation of AsO{sub 4}{sup 3{minus}} molecular structure and its vibrational spectra impeded the complete spectral interpretation. In this paper, the authors evaluated the vibrational spectroscopy of AsO{sub 4}{sup 3{minus}} in solutions, crystals, and sorbed on mineral surfaces using theoretical (semiempirical, for aqueous species) and experimental studies, with emphasis on the protonation, hydration, and metal complexation influence on the As-O symmetric stretching vibrations. Theoretical predictions are in excellent agreement with the experimental studies, and helped in the evaluation of vibrational modes of several arsenate-complexes and in the interpretation of experimental spectra.

• Sponsoring Organization: Geological Survey, Reston, VA (United States); USDOE, Washington, DC (United States); Ohio State Univ., Columbus, OH (United States)
• OSTI ID: 338613
• Journal Information: Geochimica et Cosmochimica Acta, Journal Name: Geochimica et Cosmochimica Acta Journal Issue: 19-20 Vol. 62; ISSN GCACAK; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AQUATIC ECOSYSTEMS
ARSENATES
INFRARED SPECTRA
MOLECULAR STRUCTURE
RAMAN SPECTROSCOPY
ROCK-FLUID INTERACTIONS
SOLUBILITY
VIBRATIONAL STATES