A crossed molecular beam and ab initio investigation of the exclusive methyl loss pathway in the gas phase reaction of boron monoxide (BO; X2Σ+) with dimethylacetylene (CH3CCCH3; X1A1g)

摘要: The crossed molecular beam reaction of boron monoxide (11BO; X2Σ+) with dimethylacetylene (CH3CCCH3; X1A1g) was investigated at a collision energy 23.9 ± 1.5 kJ mol−1. scattering dynamics were suggested to be indirect (complex forming reaction) and initiated by the addition 11BO(X2Σ+) radical center located atom π electron density acetylenic carbon–carbon triple bond without entrance barrier leading cis–trans11BOC4H6 doublet intermediates. cis-11BOC4H6 underwent cis–trans isomerization followed unimolecular decomposition via methyl group (CH3) loss 1-propynyl (CH3CC11BO) in an overall exoergic (experimental: −91 22 mol−1; theoretical: −105 9 NIST: −104 12 mol−1) tight exit transition state; trans-11BOC4H6 found lose instantaneously. Neither atomic nor hydrogen pathways detectable. experimental finding exclusive pathway gains full support from our computational study predicting versus branching ratio 99.99% 0.01% 1-methyl-propadienyl (CH3(11BO)CCCH2), respectively.