Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Ab initio and kinetic calculations for the reactions of H with SiH(4-n)Fn (n=1-3)
Autore:
Zhang, QZ; Wang, SK; Wang, CS; Gu, YS;
Indirizzi:
Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China Shandong Univ Jinan Peoples R China 250100 Jinan 250100, Peoples R China
Titolo Testata:
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
fascicolo: 19, volume: 3, anno: 2001,
pagine: 4280 - 4285
SICI:
1463-9076(2001)3:19<4280:AIAKCF>2.0.ZU;2-W
Fonte:
ISI
Lingua:
ENG
Soggetto:
TRANSITION-STATE THEORY; POTENTIAL-ENERGY SURFACE; DIRECT DYNAMICS METHOD; RATE CONSTANTS; HYDROGEN; SILANES; ATOMS; PATHS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
26
Recensione:
Indirizzi per estratti:
Indirizzo: Gu, YS Shandong Univ, Sch Chem & Chem Engn, Jinan 250100, Peoples R China Shandong Univ Jinan Peoples R China 250100 50100, Peoples R China
Citazione:
Q.Z. Zhang et al., "Ab initio and kinetic calculations for the reactions of H with SiH(4-n)Fn (n=1-3)", PHYS CHEM P, 3(19), 2001, pp. 4280-4285

Abstract

The reactions of H with SiH3F, SiH2F2 and SiHF3 and have been studied systematically using the direct dynamics method for the first time. A direct hydrogen abstraction mechanism has been revealed. The geometries of reactants, products and transition states have been optimized at the UMP2 level. Single-point calculations have been carried out at the G2MP2 level of theory. Based on the ab initio data, the rate constants have been calculated using the canonical variational transition state theory with the small-curvature tunneling correction method (CVT/SCT) over a wide temperature range of 200-3000 K. The CVT/SCT rate constants exhibit typical non-Arrhenius behavior. Three-parameter rate-temperature formulas are fitted as follows : k(1) (T) = (1.81 x 10(-19))T-2.85 exp(-694.74 T) for the reaction of H with SiH3F, k(2)(T) = (1.43 x 10(-20))T-3.19 exp(-1102.60/T) for the reaction of H with SiH2F2, k(3)(T) = (2.34 x 10(-20))T-2.87 exp(-2002.20/T) for the reaction of H with SiHF3, in units of cm(3) molecule(-1) s(-1). The theoretical results are in good agreement with the available experimental data. The fluorinesubstitution decreases the reactivity of the Si-H bond.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/10/20 alle ore 23:26:09