Methylidyne Complexes Prepared by Reactions of Laser-Ablated Os Atoms with Methane, Methyl Halides, and Ethane: Observation of the CH and OsH Stretching Absorptions

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• 作者：Han-Gook Cho ; Lester Andrews
• 刊名：Organometallics
• 出版年：2008
• 出版时间：April 28, 2008
• 年：2008
• 卷：27
• 期：8
• 页码：1786 - 1796
• 全文大小：455K
• 年卷期：v.27,no.8(April 28, 2008)
• ISSN：1520-6041

文摘

Simple Os carbyne complexes (HCrc="http://pubs.acs.org/images/entities/tbd1.gif">OsH₃, HCrc="http://pubs.acs.org/images/entities/tbd1.gif">OsH₂F, HCrc="http://pubs.acs.org/images/entities/tbd1.gif">OsH₂Cl, HCrc="http://pubs.acs.org/images/entities/tbd1.gif">OsH₂Br, and CH₃Crc="http://pubs.acs.org/images/entities/tbd1.gif">OsH₃) are produced in reactions of laser-ablated Os atoms with small alkanes and methyl halides via oxidative C−H insertion and α-hydrogen migration. The diagnostic methylidyne Crc="http://pubs.acs.org/images/entities/sbd_2.gif">H stretching absorptions of HCrc="http://pubs.acs.org/images/entities/tbd1.gif">OsH₃ and its halide derivatives are observed about 200 cm⁻¹ above the precursor Crc="http://pubs.acs.org/images/entities/sbd_2.gif">H stretching bands, and the frequencies are consistent with s character in hybridization in the Crc="http://pubs.acs.org/images/entities/sbd_2.gif">H bond. The methylidyne complexes all have computed C_s structures, and particularly the HCrc="http://pubs.acs.org/images/entities/tbd1.gif">OsH₃ and CH₃Crc="http://pubs.acs.org/images/entities/tbd1.gif">OsH₃ complexes have two equivalent shorter and one longer Osrc="http://pubs.acs.org/images/entities/sbd_2.gif">H bonds, parallel to the case of Re in similar complexes. The strong unique Osrc="http://pubs.acs.org/images/entities/sbd_2.gif">H stretching absorption at an exceptionally low frequency is traced to the stretching mode of the long Osrc="http://pubs.acs.org/images/entities/sbd_2.gif">H bond and antibonding character in the doubly occupied HOMO.