pentahydroxy(oxo)iridium(IX) | 176679-38-2

• 分子结构分类: 无机化合物 - 均质非金属化合物 - 均质其他非金属化合物
• 英文名称: pentahydroxy(oxo)iridium(IX)
• CAS: 176679-38-2
• 化学式: H₁₁IrO₆
• 分子量: 299.304
• InChiKey: VMNMDWXWAHLJOB-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  None
• 重原子数：
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• 可旋转键数：
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• 环数：
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• sp3杂化的碳原子比例：
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• 拓扑面积：
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• 氢给体数：
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• 氢受体数：
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反应信息

• 作为产物：
  描述：

  hexa-aquairidium(III) 以 水 为溶剂， 生成 pentahydroxy(oxo)iridium(IX)
  参考文献：
  名称：

  The Slowest Water Exchange at a Homoleptic Mononuclear Metal Center:  Variable-Temperature and Variable-Pressure ¹⁷O NMR Study on [Ir(H₂O)₆]³⁺

  摘要：

  The rate constants and activation parameters for water exchange on hexaaqua and monohydroxy pentaaqua iridium(III) have been determined by O-17 NMR spectroscopy as a function of temperature (358-406 K) and pressure (0.1-210 MPa) at several acidities (0.5-5.0 m). Noncoordinating trifluoromethanesulfonate (CF3SO3-) was used as the counterion. The observed rate constant was of the form k = k(1) + k(2)/[H+], where the subscripts 1 and 2 refer to the exchange pathways on [Ir(H2O)(6)](3+) and [Ir(H2O)(5)(OH)](2+), respectively. The kinetic parameters obtained are summarized as follows: k(1)(298) = (1.1 +/- 0.1) X 10(-10) s(-1), Delta H-1(double dagger) = 130.5 +/- 0.6 kJ mol(-1), Delta S-1(double dagger) = +2.1 +/- 1.7 J K-1 mol(-1), and Delta V-1(double dagger) = -5.7 +/- 0.5 cm(3) mol(-1); k(2)(298) = (1.4 +/- 0.6) X 10(-11) m s(-1), Delta H-2(double dagger) = 138.5 +/- 4.5 W mol(-1), Delta S-2(double dagger) = +11.5 +/- 11.6 J K-1 mol(-1), and Delta V-2(double dagger) = -0.2 +/- 0.8 cm(3) mol(-1). The value obtained for k(1)(298) corresponds to a residence time of ca. 300 years. The pK(a)(298) and the volume change Delta V-a(0) associated with the first hydrolysis of [Ir(H2O)(6)](3+) were determined by potentiometric and high-pressure spectrophotometric methods to be 4.45 +/- 0.03 and -1.5 +/- 0.3 cm(3) mol(-1), respectively. Utilizing the relation k(2) = k(OH)K(a1), values for the first-order rate constant and the corresponding activation volume for [Ir(H2O)(5)(OH)](2+) were estimated to be k(OH)(298) = 5.6 x 10(-7) s(-1) and Delta V-OH(double dagger) = +1.3 cm(3) mol(-1), respectively. These data are supportive of an associative interchange (I-a) mechanism for water exchange on [Ir(H2O)(6)](3+), but of an interchange (I) mechanism on the deprotonated species [Ir(H2O)(5)(OH)](2+). These mechanistic results have also been compared to those reported for other trivalent metal ions.

  DOI：

  10.1021/ja954071n