On the formation of ethynylbiphenyl (C14D5H5; C6D5C6H4CCH) isomers in the reaction of D5-phenyl radicals (C6D5; X2A1) with phenylacetylene (C6H5C2H; X1A1) under single collision conditions
نویسندگان
چکیده
Article history: Received 18 December 2013 In final form 6 February 2014 Available online 14 February 2014 Reaction dynamics of the D5-phenyl radical with phenylacetylene were investigated in crossed molecular beams at a collision energy of 120.7 kJ mol 1 supported by ab initio calculations. The reaction displays indirect, complex forming scattering dynamics, and adduct formation, with D5-phenyl attacking the phenyl ring of phenylacetylene at the ortho, meta and para positions over small entrance barriers. The adduct (C6D5C8H6) undergoes hydrogen emission through tight exit transition states of 34–47 kJ mol 1 above the separated products. The phenyl addition–hydrogen elimination mechanism produces various ethynylbiphenyls exoergically by 25–38 kJ mol . No phenanthrene was formed under our experimental conditions. 2014 Elsevier B.V. All rights reserved.
منابع مشابه
Indene formation under single-collision conditions from the reaction of phenyl radicals with allene and methylacetylene--a crossed molecular beam and ab initio study.
Polycyclic aromatic hydrocarbons (PAHs) are regarded as key intermediates in the molecular growth process that forms soot from incomplete fossil fuel combustion. Although heavily researched, the reaction mechanisms for PAH formation have only been investigated through bulk experiments; therefore, current models remain conjectural. We report the first observation of a directed synthesis of a PAH...
متن کاملReaction dynamics of phenyl radicals (C6H5, X2A') with methylacetylene (CH3CCH(X1A1)), allene (H2CCCH2(X1A1)), and their D4-isotopomers.
Crossed molecular beam experiments were utilized to untangle the reaction dynamics to form 1-phenylmethylacetylene [CH(3)CCC(6)H(5)] and 1-phenylallene [C(6)H(5)HCCCH(2)] in the reactions of phenyl radicals with methylacetylene and allene, respectively, over a range of collision energies from 91.4 to 161.1 kJ mol(-1). Both reactions proceed via indirect scattering dynamics and are initiated by ...
متن کاملFormation of the diphenyl molecule in the crossed beam reaction of phenyl radicals with benzene.
The chemical dynamics to form the D5-diphenyl molecule, C6H5C6D5, via the neutral-neutral reaction of phenyl radicals (C6H5) with D6-benzene (C6D6), was investigated in a crossed molecular beams experiment at a collision energy of 185 kJ mol(-1). The laboratory angular distribution and time-of-flight spectra of the C6H5C6D5 product were recorded at mass to charge mz of 159. Forward-convolution ...
متن کاملOn the formation of phenyldiacetylene (C6H5CCCCH) and D5-phenyldiacetylene (C6D5CCCCH) studied under single collision conditions.
The crossed molecular beam reactions of the phenyl and D5-phenyl radical with diacetylene (C(4)H(2)) was studied under single collision conditions at a collision energy of 46 kJ mol(-1). The chemical dynamics were found to be indirect and initiated by an addition of the phenyl/D5-phenyl radical with its radical center to the C1-carbon atom of the diacetylene reactant. This process involved an e...
متن کاملCrossed-molecular-beam study on the formation of phenylacetylene from phenyl radicals and acetylene.
During the last decades, polycyclic aromatic hydrocarbons (PAHs) and other related aromatic compounds, such as ionized PAHs, have received considerable attention from astronomers, astrobiologists, environmentalists, and the combustion community. In the interstellar medium, PAHlike species account for up to 10% of the cosmic carbon budget, have been suggested as carriers of both the unidentified...
متن کامل