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

doi:10.1246/bcsj.20160228

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

Translated title of the contribution: 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

Research output: Contribution to journal › Article › peer-review

Abstract

A representative gold(III) complex ion ([AuCl4]−), successively hydrolyzes to form [AuCl4−n(OH)n]− (n = 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)3) or hydrous gold(III) oxide (Au2O3·nH2O) 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 197Au Mössbauer spectroscopy, Au L3-edge X-ray absorption (XA) spectroscopy and thermogravimetry/differential thermal analysis (TG/DTA) measurements, the precipitate composition was estimated to be Au(OH)3. 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 H2O. This chemical and physical properties information of Au(OH)3 is essential for gold chemistry, for example, for preparing supported gold catalyst.

Translated title of the contribution	Structure of a Gold(III) Hydroxide and Determination of Its Solubility
Original language	Japanese
Pages (from-to)	1385-1390
Number of pages	6
Journal	Bulletin of the Chemical Society of Japan
Volume	89
Issue number	11
DOIs	https://doi.org/10.1246/bcsj.20160228
Publication status	Published - 2016

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@article{f78bf2fea31b45cb9db845fb0b3ffe1d,

title = "Structure of a Gold(Ⅲ) Hydroxide and Determination of Its Solubility",

abstract = "A representative gold(III) complex ion ([AuCl4]−), successively hydrolyzes to form [AuCl4−n(OH)n]− (n = 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)3) or hydrous gold(III) oxide (Au2O3·nH2O) 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 197Au M{\"o}ssbauer spectroscopy, Au L3-edge X-ray absorption (XA) spectroscopy and thermogravimetry/differential thermal analysis (TG/DTA) measurements, the precipitate composition was estimated to be Au(OH)3. 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 H2O. This chemical and physical properties information of Au(OH)3 is essential for gold chemistry, for example, for preparing supported gold catalyst.",

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

year = "2016",

doi = "10.1246/bcsj.20160228",

language = "日本語",

volume = "89",

pages = "1385--1390",

journal = "Bulletin of the Chemical Society of Japan",

issn = "0009-2673",

publisher = "The Chemical Society of Japan",

number = "11",

}

TY - JOUR

T1 - Structure of a Gold(Ⅲ) Hydroxide and Determination of Its Solubility

AU - Kawamoto, Daisuke

AU - Ando, Hiroaki

AU - Ohashi, Hironori

AU - Kobayashi, Yasuhiro

AU - Honma, Tetsuo

AU - Ishida, Tamao

AU - Tokunaga, Makoto

AU - Okaue, Yoshihiro

AU - Utsunomiya, Satoshi

AU - Yokoyama, Takushi

PY - 2016

Y1 - 2016

N2 - A representative gold(III) complex ion ([AuCl4]−), successively hydrolyzes to form [AuCl4−n(OH)n]− (n = 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)3) or hydrous gold(III) oxide (Au2O3·nH2O) 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 197Au Mössbauer spectroscopy, Au L3-edge X-ray absorption (XA) spectroscopy and thermogravimetry/differential thermal analysis (TG/DTA) measurements, the precipitate composition was estimated to be Au(OH)3. 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 H2O. This chemical and physical properties information of Au(OH)3 is essential for gold chemistry, for example, for preparing supported gold catalyst.

AB - A representative gold(III) complex ion ([AuCl4]−), successively hydrolyzes to form [AuCl4−n(OH)n]− (n = 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)3) or hydrous gold(III) oxide (Au2O3·nH2O) 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 197Au Mössbauer spectroscopy, Au L3-edge X-ray absorption (XA) spectroscopy and thermogravimetry/differential thermal analysis (TG/DTA) measurements, the precipitate composition was estimated to be Au(OH)3. 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 H2O. This chemical and physical properties information of Au(OH)3 is essential for gold chemistry, for example, for preparing supported gold catalyst.

U2 - 10.1246/bcsj.20160228

DO - 10.1246/bcsj.20160228

M3 - 学術誌

SN - 0009-2673

VL - 89

SP - 1385

EP - 1390

JO - Bulletin of the Chemical Society of Japan

JF - Bulletin of the Chemical Society of Japan

IS - 11

ER -

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

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