The photolysis of cyclobutanone

McGee, T. H.

doi:10.1021/j100851a039

Cited by 12 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mass spectrum of cyclopropanone showed the following major peaks: 56 (19.5%), 42 (7.2%), 28 (100%), 27 (30.5%), 26 (30.5%), in reasonable agreement with other determinations.11,21 Except for a small 70 peak due to cyclobutanone, no peaks at m/e >56 were detected. Absorption maxima in the uv spectra of the vapor were found at 312 (±1) nm, < 17 M-1 cm-1; and at 201 nm, e 1.0 X 103 M_1 cm-1 (see ref 22 for complete spectrum).…”

Section: Methodssupporting

confidence: 83%

Thermal, photochemical, and photophysical processes in cyclopropanone vapor

Rodriguez¹,

Chang²,

Thomas³

1976

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Section: Methodssupporting

confidence: 83%

Thermal, photochemical, and photophysical processes in cyclopropanone vapor

Rodriguez¹,

Chang²,

Thomas³

1976

J. Am. Chem. Soc.

View full text Add to dashboard Cite

“…It is difficult to assess whether or not a ring opening process precedes the production of the internally converted PFCB (So*) as in the photochemistry of cyclobutanone. 2 The following simplified primary mechanism supports our observation: PFCB (S,*) PFCB (Tj*) PFCB (S0) + hvt (8) PFCB (Tt*) (9) PFCB (S"*) (10) c -C3F6 + CO (11) At low excitation energy the ratio of kig/kg is quite small and at high excitation energy some or all of c-CsFg could be coming directly from PFCB (Si*). With this simple mechanism, we can interpret the ratio of (%C2F4)/(c-CgF6) extrapolated to zero pressure to be k\Jkg.…”

Section: Discussionsupporting

confidence: 74%

Direct and triplet-benzene-sensitized photolysis of perfluorocyclobutanone at low pressures

Lewis¹,

Lee²

1975

J. Phys. Chem.

View full text Add to dashboard Cite

Publication costs assisted by the Office of Naval Research Perfluorocyclobutanone (PFCB) has been produced in its triplet state ( ) by the triplet benzene (3Bxu, 84.5 kcal/mol) sensitization method, and the state decomposes mainly to c-CgFe and CO. Investigation of the direct photolysis of PFCB at low pressure (<5 Torr) indicates that at low excitation energies, Sx-' '**-* intersystem crossing predominates and at high energies, Sx -*»'-*• So internal conversion predominates. The internally converted PFCB (So*) decomposes unimolecularly to C2F4 and CF2CO, and the latter product further decomposes to CF2 and CO. The total product quantum yield of the "primary" processes is unity at low pressure. Our new mechanism is similar to the mechanism proposed earlier for cyclobutanone photodecomposition but is not compatible with the singlet mechanism proposed by Phillips based on the photodecomposition study carried out at higher pressures.

show abstract

“…Methyl and fluorinated methyl radicals mainly have been produced by photolysis of ketones. [2][3][4] In this work we used 1,1,1-trifluoroazomethane in an attempt to obtain a better source of these radicals. Our eventual goal is to use this chemical activation system for studies of vibrational energy transfer.…”

Section: Introductionmentioning

confidence: 99%

Nonequilibrium unimolecular reactions and collisional deactivation of chemically activated fluoroethane and 1,1,1-trifluoroethane

Chang¹,

Craig²,

Setser³

1972

J. Phys. Chem.

View full text Add to dashboard Cite

Highly vibrationally excited fluoroethane and 1,1,1-trifluoroethane molecules were generated by combination of CH2F and CF3 radicals with CHS. The radicals were produced by cophotolysis of acetone and 1,3-difluoroacetone and by photolysis of trifluoroazomethane. The nonequilibrium unimolecular rate constant for HF elimination from CH3CH2F* was measured using the acetone mixture as the bath gas. The rate constants for CH3CF3* were measured with C2F6, CH3N2CF3, c-C4F8, C6Fi4, and C8Fi8 as bath gases. RRKM calculations were done using a four-centered activated complex model and currently favored thermochemical values; good agreement was found between the calculated and both thermal and chemical activation rate constants for CH3CH2F. For the high Z>(CH3-CF3) value of ~99 kcal mol-1, the chemical activation data support a high threshold energy, 68 ± 2 kcal mol-1, for HF elimination from CH3CF3. RRKM calculations for the dissociation reactions of CH3CF3* and CH3CH2F* indicate that radical dissociation should compete with HF elimination at energies near 110 kcal mol-1. The low pressure data for CH8CF3* were analyzed according to a cascade stepladder deactivation model to obtain estimates of the average energy lost per collision. An upper limit of 10-12 kcal mol-1 is implied for even the larger bath gas molecules.

show abstract

The photolysis of cyclobutanone

Cited by 12 publications

References 1 publication

Thermal, photochemical, and photophysical processes in cyclopropanone vapor

Thermal, photochemical, and photophysical processes in cyclopropanone vapor

Direct and triplet-benzene-sensitized photolysis of perfluorocyclobutanone at low pressures

Nonequilibrium unimolecular reactions and collisional deactivation of chemically activated fluoroethane and 1,1,1-trifluoroethane

Contact Info

Product

Resources

About