Matches in SemOpenAlex for { <https://semopenalex.org/work/W2007993880> ?p ?o ?g. }
- W2007993880 endingPage "1252" @default.
- W2007993880 startingPage "1243" @default.
- W2007993880 abstract "The local environment around Au (III) in aqueous solutions containing 1 M NaCl was determined as a function of pH and Au concentration using X-ray absorption spectroscopy (XAS) at ambient temperature and pressure. The solution Au concentrations studied were 10− to 10−3 M and the pH ranged between 2 and 9.2. No significant changes of Au speciation were detected with increasing Au concentration; however, major speciation changes were caused by variations in pH. At pH = 2, Au is coordinated by four Cl atoms (mean d [AuCl] = 2.28 –2.29 ± 0.01 Å), whereas at pH 7.5 and 9.2, Au is coordinated by three Cl and one O (or OH) and by two Cl and two O (or OH), respectively (mean d[AuCl] = 2.28 ± 0.02 Å; mean d[AuO or AuOH] = 1.97 ± 0.02 Å), indicating replacement of Cl by O (or OH) with increasing pH. In all solutions studied, the number of first-neighbors around Au(III) is close to four. XANES analysis suggests the presence of a square-planar geometry for AuX4 (X = Cl, O) at all pH values studied. These results are in excellent agreement with those from our previous Raman, resonance Raman, and UV/visible spectroscopy study of gold(III)-chloride solutions (PECK et al., 1991), which found that AuCl4−, AuCl3(OH)−, and AuCl2(OH)2− are the majority species in the pH ranges 2–6, 6–8.5, and 8.5–11, respectively. We did not find evidence for Au(I)Cl2− or Au(I)Cl(OH)− complexes in our pH 7.5 and 9.2 solutions, as was recently suggested by Pan and Wood (1991) for acidic gold chloride solutions at temperatures > 100°C, although we can't rule these complexes out as minority species (<10% of the total Au in solution). Our EXAFS results also provide the first direct evidence for Cl second neighbors around AuCl4− complexes in the most acidic solutions studied (pH = 2 and 4.5). These second-neighbor Cl atoms were also detected at low Au concentrations (10−3 M) and are similar in number and arrangement to those observed in crystalline KAuCL4·2H2O (two Cl at a mean d[Au-Cl(2)] = 4.42 ± 0.03 Å). No evidence was found for second-neighbor Au atoms, which indicates little or no Au polymers or colloidal particles in any of the solutions studied. Our EXAFS results are in broad agreement with earlier predictions of Au speciation based on a variety of chemical measurements. Moreover, they directly confirm that mixed chloro-hydroxo Au (III) complexes are more stable than predicted on the basis of thermodynamically estimated stability constants." @default.
- W2007993880 created "2016-06-24" @default.
- W2007993880 creator A5002171426 @default.
- W2007993880 creator A5047538618 @default.
- W2007993880 creator A5049749229 @default.
- W2007993880 date "1993-03-01" @default.
- W2007993880 modified "2023-10-17" @default.
- W2007993880 title "Local environment around gold (III) in aqueous chloride solutions: An EXAFS spectroscopy study" @default.
- W2007993880 cites W1965524050 @default.
- W2007993880 cites W1966299050 @default.
- W2007993880 cites W1967223759 @default.
- W2007993880 cites W1968779462 @default.
- W2007993880 cites W1971228775 @default.
- W2007993880 cites W1974257295 @default.
- W2007993880 cites W1975861833 @default.
- W2007993880 cites W1984135038 @default.
- W2007993880 cites W2000873955 @default.
- W2007993880 cites W2005758842 @default.
- W2007993880 cites W2006737361 @default.
- W2007993880 cites W2010110408 @default.
- W2007993880 cites W2011961114 @default.
- W2007993880 cites W2013417199 @default.
- W2007993880 cites W2014117423 @default.
- W2007993880 cites W2022664104 @default.
- W2007993880 cites W2023511998 @default.
- W2007993880 cites W2025742271 @default.
- W2007993880 cites W2029273362 @default.
- W2007993880 cites W2035198059 @default.
- W2007993880 cites W2036959539 @default.
- W2007993880 cites W2042488345 @default.
- W2007993880 cites W2044238202 @default.
- W2007993880 cites W2046546586 @default.
- W2007993880 cites W2048419852 @default.
- W2007993880 cites W2059609107 @default.
- W2007993880 cites W2059709865 @default.
- W2007993880 cites W2066676707 @default.
- W2007993880 cites W2067326287 @default.
- W2007993880 cites W2068401177 @default.
- W2007993880 cites W2071550235 @default.
- W2007993880 cites W2076966029 @default.
- W2007993880 cites W2077917573 @default.
- W2007993880 cites W2078588057 @default.
- W2007993880 cites W2081936026 @default.
- W2007993880 cites W2084674052 @default.
- W2007993880 cites W2085944512 @default.
- W2007993880 cites W2089073967 @default.
- W2007993880 cites W2093647057 @default.
- W2007993880 cites W2094118649 @default.
- W2007993880 cites W2095111473 @default.
- W2007993880 cites W2098347203 @default.
- W2007993880 cites W2119361134 @default.
- W2007993880 cites W2167233505 @default.
- W2007993880 cites W2172299527 @default.
- W2007993880 cites W2312443981 @default.
- W2007993880 cites W2557127207 @default.
- W2007993880 cites W2571934832 @default.
- W2007993880 cites W2621734302 @default.
- W2007993880 doi "https://doi.org/10.1016/0016-7037(93)90061-z" @default.
- W2007993880 hasPublicationYear "1993" @default.
- W2007993880 type Work @default.
- W2007993880 sameAs 2007993880 @default.
- W2007993880 citedByCount "101" @default.
- W2007993880 countsByYear W20079938802012 @default.
- W2007993880 countsByYear W20079938802013 @default.
- W2007993880 countsByYear W20079938802014 @default.
- W2007993880 countsByYear W20079938802015 @default.
- W2007993880 countsByYear W20079938802016 @default.
- W2007993880 countsByYear W20079938802017 @default.
- W2007993880 countsByYear W20079938802018 @default.
- W2007993880 countsByYear W20079938802019 @default.
- W2007993880 countsByYear W20079938802020 @default.
- W2007993880 countsByYear W20079938802021 @default.
- W2007993880 countsByYear W20079938802022 @default.
- W2007993880 countsByYear W20079938802023 @default.
- W2007993880 crossrefType "journal-article" @default.
- W2007993880 hasAuthorship W2007993880A5002171426 @default.
- W2007993880 hasAuthorship W2007993880A5047538618 @default.
- W2007993880 hasAuthorship W2007993880A5049749229 @default.
- W2007993880 hasConcept C107861141 @default.
- W2007993880 hasConcept C110715899 @default.
- W2007993880 hasConcept C113196181 @default.
- W2007993880 hasConcept C119824511 @default.
- W2007993880 hasConcept C120665830 @default.
- W2007993880 hasConcept C121332964 @default.
- W2007993880 hasConcept C125287762 @default.
- W2007993880 hasConcept C147789679 @default.
- W2007993880 hasConcept C159985019 @default.
- W2007993880 hasConcept C178790620 @default.
- W2007993880 hasConcept C179104552 @default.
- W2007993880 hasConcept C184651966 @default.
- W2007993880 hasConcept C185592680 @default.
- W2007993880 hasConcept C192562407 @default.
- W2007993880 hasConcept C2778695967 @default.
- W2007993880 hasConcept C32891209 @default.
- W2007993880 hasConcept C40003534 @default.
- W2007993880 hasConcept C43617362 @default.
- W2007993880 hasConcept C62284982 @default.
- W2007993880 hasConcept C62520636 @default.