Probing the Presence of Multiple Metal鈥揗etal Bonds in Technetium Chlorides by X-ray Absorption Spectroscopy: Implications for Synthetic Chemistry

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• 作者：Frederic Poineau ; Erik V. Johnstone ; Paul M. Forster ; Longzou Ma ; Alfred P. Sattelberger ; Kenneth R. Czerwinski
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：September 3, 2012
• 年：2012
• 卷：51
• 期：17
• 页码：9563-9570
• 全文大小：375K
• 年卷期：v.51,no.17(September 3, 2012)
• ISSN：1520-510X

文摘

The cesium salts of [Tc₂X₈]^{3鈥?/sup> (X = Cl, Br), the reduction product of (n-Bu₄N)[TcOCl₄] with (n-Bu₄N)BH₄ in THF, and the product obtained from reaction of Tc₂(O₂CCH₃)₄Cl₂ with HCl(g) at 300 掳C have been characterized by extended X-ray absorption fine structure (EXAFS) spectroscopy. For the [Tc₂X₈]3鈥?/sup> anions, the Tc鈥揟c separations found by EXAFS spectroscopy (2.12(2) 脜 for both X = Cl and Br) are in excellent agreement with those found by single-crystal X-ray diffraction (SCXRD) measurements (2.117[4] 脜 for X = Cl and 2.1265(1) 脜 for X = Br). The Tc鈥揟c separation found by EXAFS in these anions is slightly shorter than those found in the [Tc₂X₈]2鈥?/sup> anions (2.16(2) 脜 for X = Cl and Br). Spectroscopic and SCXRD characterization of the reduction product of (n-Bu₄N)[TcOCl₄] with (n-Bu₄N)BH₄ are consistent with the presence of dinuclear species that are related to the [Tc₂Cl₈]n鈭?/sup> (n = 2, 3) anions. From these results, a new preparation of (n-Bu₄N)₂[Tc₂Cl₈] was developed. Finally, EXAFS characterization of the product obtained from reaction of Tc₂(O₂CCH₃)₄Cl₂ with HCl(g) at 300 掳C indicates the presence of amorphous 伪-TcCl₃. The Tc鈥揟c separation (i.e., 2.46(2) 脜) measured in this compound is consistent with the presence of Tc鈺怲c double bonds in the [Tc₃]9+ core.}