The dynamics of reaction of Cl atoms with tetramethylsilane.
Rotational state distributions and state-selected CM-frame angular distributions were measured for HCl (v' = 0, j') products from the reaction of Cl-atoms with tetramethylsilane (TMS) under single collision conditions at a collision energy, E(coll), of 8.2 +/- 2.0 kcal mol(-1). The internal excitation of these products was very low with only 2% of the total energy available partitioned into HCl rotation. A transition state with a quasi-linear C-H-Cl moiety structure was computed and used to explain this finding. A backward peaking differential cross section was also reported together with a product translational energy (T') distribution with a maximum at T' approximately E(coll). This scattering behaviour is accounted for by reactions proceeding through a tight transition state on a highly skewed potential energy surface, which favours collisions at low impact parameters with a strong kinematic constraint on the internal excitation of the products. The large Arrhenius pre-exponential factor previously reported for this reaction is reconciled with the tight differential scattering observed in our study by considering the large size of the TMS molecule.
Retail
Bertrand
B
School of Chemistry, University of Bristol, Cantock's Close, Bristol, UK BS8 1TS.
Rose
Rebecca A
RA
Pearce
Julie K
JK
Greaves
Stuart J
SJ
Orr-Ewing
Andrew J
AJ
D000465:Algorithms; D016880:Anisotropy; D002713:Chlorine / Q000737:chemistry* / Q000528:radiation effects; D004980:Ethane / Q000737:chemistry; D006851:Hydrochloric Acid / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods; D008958:Models, Molecular; D010782:Photolysis; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
D014297:Trimethylsilyl Compounds; C073196:tetramethylsilane; D002713:Chlorine; D004980:Ethane; D006851:Hydrochloric Acid