Conversion of a hydrido-butenylcarbyne complex to η2-allene- coordinated complexes and metallabenzenes

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	Conversion of a hydrido-butenylcarbyne complex to η2-allene- coordinated complexes and metallabenzenes
	Chen, Jinxiang ; Zhang, Chunhong ; Xie, Tingwan ; Wen, Ting Bin ; Zhang, Hong ; Xia, Haiping ; Wen TB(温庭斌) ; Zhang H(张弘) ; Xia HP(夏海平)
刊名	http://dx.doi.org/10.1021/om400469e
	2013-07-22
关键词	Aromatic compounds Cyanides Density functional theory Hydrocarbons Ligands Nuclear magnetic resonance spectroscopy Osmium Substitution reactions X ray diffraction
英文摘要	Treatment of OsCl2(PPh3)3 with HC≡CCH(OH)Et produces the cyclic complex Os(PPh3) 2Cl2(CHC(PPh3)CH(OH)CH2CH 3) (1), which can undergo dehydration to give the hydrido-alkenylvinylidene complex Os(PPh3)2HCl 2(-C-C(PPh3)CH-CHCH3) (2). Reaction of 2 with HBF4 generates the hydrido-butenylcarbyne complex [OsHCl 2(≡CC(PPh3)-CH(Et))(PPh3) 2]BF4 (3). The complex 3 evolves into the unstable metallabenzene [(PPh3)2(RCN)ClOs(CHC(PPh 3)CHCHCH)]BF4 (4; RCN = benzonitrile, 2-cyanobenzaldehyde, 3-methoxyacrylonitrile, 2-cyanoacetamide) via triple hydrogen eliminations in the presence of excess nitriles in refluxing CHCl3 in an air atmosphere. The ligand substitution reaction of 4 with excess CO affords the stable metallabenzene product [(PPh3)2(CO) ClOs(CHC(PPh3)CHCHCH)]BF4 (5). The key intermediates, η2-allene-coordinated osmium complexes [(PPh3) 2(RCN)ClOs(CH-C(PPh3)CH-C-CH2)]BF4 (6; RCN = benzonitrile, 2-cyanobenzaldehyde, 3-methoxyacrylonitrile, 2-cyanoacetamide) can be captured by performing the conversion at room temperature. Remarkably, in the absence of nitriles, reaction of 3 with excess CO only generates the vinylethenyl complex [(PPh3) 2(CO)2ClOs(CH-C(PPh3)CH-CHCH 3)]BF4 (7). The complexes 1-3, 5, 6a, and 7 have been structurally characterized by single-crystal X-ray diffraction. Detailed mechanisms of the conversions have been investigated with the aid of density functional theory (DFT) calculations. DFT calculations suggest that the high stablility of the carbonyl coordinated complexes in the conversion inhibits the further transformation to metallabenzene product. However, the transformation is both kinetically and thermodynamically favorable in the presence of the relatively weaker nitrile ligand, which is consistent with the experimental conversion of 3 to 5 via unstable metallabenzenes 4 observed for in situ NMR experiments. ? 2013 American Chemical Society.
语种	英语
出版者	American Chemical Society
内容类型	期刊论文
源URL	[http://dspace.xmu.edu.cn/handle/2288/89170]
专题	化学化工－已发表论文
推荐引用方式 GB/T 7714	Chen, Jinxiang,Zhang, Chunhong,Xie, Tingwan,et al. Conversion of a hydrido-butenylcarbyne complex to η2-allene- coordinated complexes and metallabenzenes[J]. http://dx.doi.org/10.1021/om400469e,2013.
APA	Chen, Jinxiang.,Zhang, Chunhong.,Xie, Tingwan.,Wen, Ting Bin.,Zhang, Hong.,...&夏海平.(2013).Conversion of a hydrido-butenylcarbyne complex to η2-allene- coordinated complexes and metallabenzenes.http://dx.doi.org/10.1021/om400469e.
MLA	Chen, Jinxiang,et al."Conversion of a hydrido-butenylcarbyne complex to η2-allene- coordinated complexes and metallabenzenes".http://dx.doi.org/10.1021/om400469e (2013).