Activation of Methane by Zinc: Gas-Phase Synthesis, Structure, and Bonding of HZnCH3
Activation of Methane by Zinc: Gas-Phase Synthesis, Structure, and Bonding of HZnCH3
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DOI：
10.1021/ja106121v
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发表时间：
2010-12-08
影响因子：
15
通讯作者：
Ziurys, Lucy M.
中科院分区：
文献类型：
--
作者：
Flory, Michael A.;Apponi, Aldo J.;Ziurys, Lucy M.
甲基氢化锌分子，HZnCH 3，已被观察到在气相中的单体形式的第一次使用高分辨率光谱技术。该分子通过两种方法合成：二甲基锌与氢气和甲烷在交流放电中的反应以及在Broida型烘箱中产生的锌蒸气与甲烷在直流放电中的反应。HZnCH 3是根据其纯旋转光谱确定的，该光谱分别在332-516 GHz和18-41 GHz的频率范围内使用毫米/亚毫米直接吸收和傅里叶变换微波技术记录。在七个同位素变体中测量了该分子的多个旋转跃迁。在所有的光谱中明显存在K-梯状结构，表明分子具有C-3v对称性和（1）A（1）基态电子态。对于（HZnCH 3）-Zn-67物种，观察到由Zn-67核产生的广泛的四极超精细结构，表明与锌原子共价键合。从多个同位素取代，HZnCH 3的精确结构已被确定。轴向氢原子的影响使甲基稍微变形，但使Zn-C键稳定。该研究表明，在一定条件下，锌与甲烷在气相中氧化加成可以生成HZnCH 3。HZnCH 3是第一个被结构表征的金属-甲烷插入配合物。
The methylzinc hydride molecule, HZnCH3, has been observed in the gas phase for the first time in the monomeric form using high-resolution spectroscopic techniques. The molecule was synthesized by two methods: the reaction of dimethylzinc with hydrogen gas and methane in an AC discharge and the reaction of zinc vapor produced in a Broida-type oven with methane in a DC discharge. HZnCH3 was identified on the basis of its pure rotational spectrum, which was recorded using millimeter/submillimeter direct-absorption and Fourier transform microwave techniques over the frequency ranges 332-516 GHz and 18-41 GHz, respectively. Multiple rotational transitions were measured for this molecule in seven isotopic variants. K-ladder structure was clearly present in all of the spectra, indicating a molecule with C-3v symmetry and a (1)A(1) ground electronic state. Extensive quadrupole hyperfine structure arising from the Zn-67 nucleus was observed for the (HZnCH3)-Zn-67 species, suggesting covalent bonding to the zinc atom. From the multiple isotopic substitutions, a precise structure for HZnCH3 has been determined. The influence of the axial hydrogen atom slightly distorts the methyl group but stabilizes the Zn-C bond. This study suggests that HZnCH3 can be formed through the oxidative addition of zinc to methane in the gas phase under certain conditions. HZnCH3 is the first metal-methane insertion complex to be structurally characterized.