Jian Xianhui, Xin Ke, Hu Jin, Zhang Luning, Wang Xuefeng, Wang Guanjun
School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, 1239 Siping Road, Shanghai 200092, China.
Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, 2005 Songhu Road, Shanghai 200438, China.
J Phys Chem A. 2021 Jun 17;125(23):5054-5060. doi: 10.1021/acs.jpca.1c03185. Epub 2021 Jun 4.
The solvent effect of the TaO reaction with water molecules in the gas phase is examined. Stoichiometric TaO(HO) cations are generated by the laser vaporization of a tantalum metal target in the pulsed supersonic expansion of HO/He mixed gas. The infrared photodissociation spectra of TaO(HO) cations are measured using the argon-tagging technology in the 2800-3850 cm region. Density functional theory calculations are carried out to identify the observed infrared bands and elucidate the reaction mechanism. In the TaO reaction with one HO molecule, both the hydrated adduct HO-TaO and dihydroxide TaO(OH) are generated. The coexistence of tetrahydroxide Ta(OH) and hydrated dihydroxide HO-TaO(OH) is seen when the second HO molecule is involved. However, only the hydrated HO-Ta(OH) product is obtained in the TaO reaction with three HO molecules. Theoretical calculations indicate that in the reaction, the formation of a six-membered cyclic transition state through the hydrogen bond lowers the energy barrier significantly, which promotes the transfer of the hydrogen of hydrated adducts to generate di- and tetrahydroxides.
研究了气相中TaO与水分子的溶剂效应。通过在HO/He混合气体的脉冲超声速膨胀中对钽金属靶进行激光汽化，生成化学计量比的TaO(HO)阳离子。利用氩标记技术在2800 - 3850 cm区域测量TaO(HO)阳离子的红外光解离光谱。进行密度泛函理论计算以识别观察到的红外波段并阐明反应机理。在TaO与一个HO分子的反应中，生成了水合加合物HO - TaO和二氢氧化物TaO(OH)。当涉及第二个HO分子时，可以看到四氢氧化物Ta(OH)和水合二氢氧化物HO - TaO(OH)共存。然而，在TaO与三个HO分子的反应中，仅得到水合HO - Ta(OH)产物。理论计算表明，在该反应中，通过氢键形成六元环状过渡态显著降低了能垒，促进了水合加合物中氢的转移以生成二氢氧化物和四氢氧化物。
