Structure of a Gold(Ⅲ) Hydroxide and Determination of Its Solubility

Daisuke Kawamoto, Hiroaki Ando, Hironori Ohashi, Yasuhiro Kobayashi, Tetsuo Honma, Tamao Ishida, Makoto Tokunaga, Yoshihiro Okaue, Satoshi Utsunomiya, Takushi Yokoyama

研究成果: ジャーナルへの寄稿学術誌査読


<p>A representative gold(III) complex ion ([AuCl<sub>4</sub>]<sup>−</sup>), successively hydrolyzes to form [AuCl<sub>4−</sub><i><sub>n</sub></i>(OH)<i><sub>n</sub></i>]<sup>−</sup> (<i>n</i> = 0–4) in aqueous solution as the pH increases and, finally, precipitates. It has been referred to as "gold(III) hydroxide" for the past fifty years. However, whether the precipitate is gold(III) hydroxide (Au(OH)<sub>3</sub>) or hydrous gold(III) oxide (Au<sub>2</sub>O<sub>3</sub>·<i>n</i>H<sub>2</sub>O) has remained uncertain. Few studies have been conducted to determine its chemical and physical properties. The aim of this investigation is to identify the precipitate and to determine its solubility. The precipitate was X-ray amorphous. Based on the transmission electron microscopy (TEM) observation, the shape was spherical and the particle diameter was approximately 9 nm. From the results of <sup>197</sup>Au Mössbauer spectroscopy, Au L<sub>3</sub>-edge X-ray absorption (XA) spectroscopy and thermogravimetry/differential thermal analysis (TG/DTA) measurements, the precipitate composition was estimated to be Au(OH)<sub>3</sub>. Based on the composition, its structure was proposed to be a linear polymer. Moreover, its solubility at 298 K was determined to be 0.00120 g/100 g of H<sub>2</sub>O. This chemical and physical properties information of Au(OH)<sub>3</sub> is essential for gold chemistry, for example, for preparing supported gold catalyst.</p>
寄稿の翻訳タイトルStructure of a Gold(III) Hydroxide and Determination of Its Solubility
ジャーナルBulletin of the Chemical Society of Japan
出版ステータス出版済み - 2016


「Structure of a Gold(Ⅲ) Hydroxide and Determination of Its Solubility」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。