Matches in SemOpenAlex for { <https://semopenalex.org/work/W2952364693> ?p ?o ?g. }
Showing items 1 to 74 of
74
with 100 items per page.
- W2952364693 endingPage "1997" @default.
- W2952364693 startingPage "1988" @default.
- W2952364693 abstract "The photochemical ring opening of cis- and trans-3,4-dimethyl-, 1,3,4-trimethyl-, and 1,2,3,4-tetramethylcyclobutene (1, 3, and 4, respectively) has been investigated in hydrocarbon solution with 193 nm and 214 nm light sources. Ring opening is non-stereospecific in all cases at both wavelengths. The ratio of dienes formed by the formally allowed to formally forbidden pathways in the photolysis of these compounds is highest (ca. 2) for the trimethylcyclobutenes, and approximately 1 for both cis and trans isomers of the di- and tetramethylcyclobutenes with 193 nm excitation. The diene distributions from photolysis of all compounds but cis-3 show slight wavelength dependence. Gas- and solution-phase UV absorption spectra are reported for 3 and 4, and indicate that there are at least three singlet excited states accessible in the 185–230 nm region in these molecules. The π,R(3s) state is the lowest energy state in the gas phase in 3 and 4. The results verify that orbital symmetry factors do not play a role (or a consistent one, at least) in controlling the stereochemistry of the reaction, but they do not allow a firm assignment of the excited state(s) responsible for ring opening. Direct photolysis of these compounds also results in fragmentation to yield Z-2-butene (from cis-3 and 4) or E-2-butene (from trans-3 and 4) in addition to propyne or 2-butyne. The 2-butenes are formed with greater than 90% stereospecificity in all cases. The structures of the four 3-methyl-2,4-hexadiene isomers obtained from photolysis of 3 have been assigned on the basis of 1 H NMR spectroscopy and the results of thermolysis of the two cyclobutene isomers. Keywords: cyclobutene, photolysis, Rydberg, orbital symmetry, far-UV, solution phase, UV spectra." @default.
- W2952364693 created "2019-06-27" @default.
- W2952364693 creator A5012744663 @default.
- W2952364693 creator A5037700610 @default.
- W2952364693 creator A5039281567 @default.
- W2952364693 date "1990-11-01" @default.
- W2952364693 modified "2023-09-23" @default.
- W2952364693 title "Cyclobutene photochemistry. Substituent and wavelength effects on the photochemical ring opening of monocyclic alkylcyclobutenes" @default.
- W2952364693 doi "https://doi.org/10.1139/v90-305" @default.
- W2952364693 hasPublicationYear "1990" @default.
- W2952364693 type Work @default.
- W2952364693 sameAs 2952364693 @default.
- W2952364693 citedByCount "6" @default.
- W2952364693 crossrefType "journal-article" @default.
- W2952364693 hasAuthorship W2952364693A5012744663 @default.
- W2952364693 hasAuthorship W2952364693A5037700610 @default.
- W2952364693 hasAuthorship W2952364693A5039281567 @default.
- W2952364693 hasConcept C121332964 @default.
- W2952364693 hasConcept C126661725 @default.
- W2952364693 hasConcept C161790260 @default.
- W2952364693 hasConcept C176788430 @default.
- W2952364693 hasConcept C178790620 @default.
- W2952364693 hasConcept C181500209 @default.
- W2952364693 hasConcept C185544564 @default.
- W2952364693 hasConcept C185592680 @default.
- W2952364693 hasConcept C187921627 @default.
- W2952364693 hasConcept C2776011334 @default.
- W2952364693 hasConcept C2777197226 @default.
- W2952364693 hasConcept C2777811443 @default.
- W2952364693 hasConcept C2778689049 @default.
- W2952364693 hasConcept C2780378348 @default.
- W2952364693 hasConcept C33062035 @default.
- W2952364693 hasConcept C54582936 @default.
- W2952364693 hasConcept C71240020 @default.
- W2952364693 hasConcept C75473681 @default.
- W2952364693 hasConceptScore W2952364693C121332964 @default.
- W2952364693 hasConceptScore W2952364693C126661725 @default.
- W2952364693 hasConceptScore W2952364693C161790260 @default.
- W2952364693 hasConceptScore W2952364693C176788430 @default.
- W2952364693 hasConceptScore W2952364693C178790620 @default.
- W2952364693 hasConceptScore W2952364693C181500209 @default.
- W2952364693 hasConceptScore W2952364693C185544564 @default.
- W2952364693 hasConceptScore W2952364693C185592680 @default.
- W2952364693 hasConceptScore W2952364693C187921627 @default.
- W2952364693 hasConceptScore W2952364693C2776011334 @default.
- W2952364693 hasConceptScore W2952364693C2777197226 @default.
- W2952364693 hasConceptScore W2952364693C2777811443 @default.
- W2952364693 hasConceptScore W2952364693C2778689049 @default.
- W2952364693 hasConceptScore W2952364693C2780378348 @default.
- W2952364693 hasConceptScore W2952364693C33062035 @default.
- W2952364693 hasConceptScore W2952364693C54582936 @default.
- W2952364693 hasConceptScore W2952364693C71240020 @default.
- W2952364693 hasConceptScore W2952364693C75473681 @default.
- W2952364693 hasIssue "11" @default.
- W2952364693 hasLocation W29523646931 @default.
- W2952364693 hasOpenAccess W2952364693 @default.
- W2952364693 hasPrimaryLocation W29523646931 @default.
- W2952364693 hasRelatedWork W2005456805 @default.
- W2952364693 hasRelatedWork W2015814283 @default.
- W2952364693 hasRelatedWork W2039813207 @default.
- W2952364693 hasRelatedWork W2070737839 @default.
- W2952364693 hasRelatedWork W2070884387 @default.
- W2952364693 hasRelatedWork W2073049740 @default.
- W2952364693 hasRelatedWork W2322091405 @default.
- W2952364693 hasRelatedWork W2326355836 @default.
- W2952364693 hasRelatedWork W2952364693 @default.
- W2952364693 hasRelatedWork W4252322913 @default.
- W2952364693 hasVolume "68" @default.
- W2952364693 isParatext "false" @default.
- W2952364693 isRetracted "false" @default.
- W2952364693 magId "2952364693" @default.
- W2952364693 workType "article" @default.