Cho Han-Gook, Andrews Lester
Department of Chemistry, Incheon National University , 119 Academy-ro, Yeonsu-gu, Incheon 22012, South Korea.
Department of Chemistry, University of Virginia , P.O. Box 400319, Charlottesville, Virginia 22904-4319, United States.
J Phys Chem A. 2017 Nov 16;121(45):8583-8595. doi: 10.1021/acs.jpca.7b06785. Epub 2017 Nov 1.
CHCH-MH and (CH)-MH were identified in the matrix IR spectra from reactions of laser-ablated group 3 metal atoms with ethane, and they were characterized via theoretical investigations. The observed products are the most stable in the proposed reaction path. Because of the small number of valence electrons, the group 3 metal high oxidation-state complexes are less stable. The C-C insertion product [(CH)M], which was predicted to be more stable than the observed ones, was not observed probably because of the high energy barrier and a likely slower rate for insertion into one C-C bond than one of six C-H bonds. The C-C bond of the metallacyclopropanes is the shortest among the early transition-metal analogues, and its stretching frequencies are the highest, revealing the weakest interaction between the metal dihydride and ethylidene groups. The undetected ethylidene is not agostic, parallel to the previously examined methylidene.
在激光烧蚀的第3族金属原子与乙烷反应的基质红外光谱中鉴定出了CHCH-MH和(CH)-MH，并通过理论研究对它们进行了表征。在所提出的反应路径中，观察到的产物是最稳定的。由于价电子数量较少，第3族金属高氧化态配合物不太稳定。预测比观察到的产物更稳定的C-C插入产物[(CH)M]未被观察到，可能是因为能垒高，且插入一个C-C键的速率可能比插入六个C-H键之一的速率慢。金属环丙烷的C-C键在早期过渡金属类似物中是最短的，其伸缩频率最高，这表明金属二氢化物与亚乙基之间的相互作用最弱。未检测到的亚乙基不像之前研究的亚甲基那样存在邻位相互作用。
