Matches in SemOpenAlex for { <https://semopenalex.org/work/W2007264108> ?p ?o ?g. }
Showing items 1 to 98 of
98
with 100 items per page.
- W2007264108 endingPage "4988" @default.
- W2007264108 startingPage "4980" @default.
- W2007264108 abstract "The rate of bond inversion at the nitrogen atom in aziridine (dimethylene-imine) was measured in the gas phase for a range of pressures and temperatures. 1H NMR spectra were recorded of samples at 5–1100 Torr, and from 298 to 388 K. Rate constants for inversion were derived by complete line shape analysis of the NMR spectra. Their temperature dependence at the high pressure limit (1100 Torr) gave Ea =15.8±0.4 kcal mol−1; ΔH‡ =15.2±0.4 kcal mol−1; ΔS‡=−5.5±3 eu; and ΔG‡298=16.8±0.5 kcal mol−1. These values are in excellent agreement with previously reported mangitudes obtained for solutions and in the gas phase at high pressures. However, at all temperatures we found no dependence of the first order rate constants on pressure down to 5 Torr, in sharp contrast to the fall-off curves calculated with standard RRKM codes, which indicated that for pressures below 100 Torr this system should be in the bimolecular regime. A less extended set of measurements was made with 2-methyl-aziridine which does show a small but clear fall off in kuni. These results can be rationalized in terms of the regional phase space model, previously proposed for methylnitrite. In systems such as aziridine, where the density of states at the barrier height is sparse (≈10/cm−1) the rate of inversion is limited by the relaxation time for intramolecular vibrational energy redistribution. Our results indicate that many nanoseconds are required to attain relaxation rather than picoseconds, estimated from the Marcus formula for k23(E)=N‡(E+)/hρ(E). In the methyl-substituted analog the barrier height is approximately 3 kcal mol−1 higher, and the density of states at this barrier is higher than in aziridine. Relaxation data for conformational changes in C6H12, H3CONO, SF4, and C5H10O were reanalyzed in terms of the regional phase-space model. At low pressures these also show departures from RRKM predictions." @default.
- W2007264108 created "2016-06-24" @default.
- W2007264108 creator A5027818503 @default.
- W2007264108 creator A5051085021 @default.
- W2007264108 date "1986-11-01" @default.
- W2007264108 modified "2023-09-26" @default.
- W2007264108 title "Intramolecular conversions over low barriers. VII. The aziridine inversion—Intrinsically non‐RRKM" @default.
- W2007264108 cites W1573664144 @default.
- W2007264108 cites W1965069710 @default.
- W2007264108 cites W1968400799 @default.
- W2007264108 cites W1978643301 @default.
- W2007264108 cites W1987941895 @default.
- W2007264108 cites W1996960719 @default.
- W2007264108 cites W1998096276 @default.
- W2007264108 cites W1999275936 @default.
- W2007264108 cites W2000174596 @default.
- W2007264108 cites W2008480228 @default.
- W2007264108 cites W2012631382 @default.
- W2007264108 cites W2015051801 @default.
- W2007264108 cites W2033455666 @default.
- W2007264108 cites W2040410660 @default.
- W2007264108 cites W2043778106 @default.
- W2007264108 cites W2047938482 @default.
- W2007264108 cites W2051670997 @default.
- W2007264108 cites W2053825703 @default.
- W2007264108 cites W2074830462 @default.
- W2007264108 cites W2078099150 @default.
- W2007264108 cites W2083397857 @default.
- W2007264108 cites W2087586295 @default.
- W2007264108 cites W2090376389 @default.
- W2007264108 cites W2092854440 @default.
- W2007264108 cites W2321915310 @default.
- W2007264108 cites W2331063400 @default.
- W2007264108 cites W2335283616 @default.
- W2007264108 cites W2951287438 @default.
- W2007264108 cites W2992011072 @default.
- W2007264108 doi "https://doi.org/10.1063/1.451712" @default.
- W2007264108 hasPublicationYear "1986" @default.
- W2007264108 type Work @default.
- W2007264108 sameAs 2007264108 @default.
- W2007264108 citedByCount "51" @default.
- W2007264108 countsByYear W20072641082013 @default.
- W2007264108 countsByYear W20072641082015 @default.
- W2007264108 countsByYear W20072641082020 @default.
- W2007264108 crossrefType "journal-article" @default.
- W2007264108 hasAuthorship W2007264108A5027818503 @default.
- W2007264108 hasAuthorship W2007264108A5051085021 @default.
- W2007264108 hasConcept C121332964 @default.
- W2007264108 hasConcept C1276947 @default.
- W2007264108 hasConcept C147789679 @default.
- W2007264108 hasConcept C148898269 @default.
- W2007264108 hasConcept C178790620 @default.
- W2007264108 hasConcept C185592680 @default.
- W2007264108 hasConcept C2778544067 @default.
- W2007264108 hasConcept C2780378348 @default.
- W2007264108 hasConcept C30646810 @default.
- W2007264108 hasConcept C4839761 @default.
- W2007264108 hasConcept C62520636 @default.
- W2007264108 hasConcept C71240020 @default.
- W2007264108 hasConcept C75079739 @default.
- W2007264108 hasConcept C93391505 @default.
- W2007264108 hasConcept C97355855 @default.
- W2007264108 hasConceptScore W2007264108C121332964 @default.
- W2007264108 hasConceptScore W2007264108C1276947 @default.
- W2007264108 hasConceptScore W2007264108C147789679 @default.
- W2007264108 hasConceptScore W2007264108C148898269 @default.
- W2007264108 hasConceptScore W2007264108C178790620 @default.
- W2007264108 hasConceptScore W2007264108C185592680 @default.
- W2007264108 hasConceptScore W2007264108C2778544067 @default.
- W2007264108 hasConceptScore W2007264108C2780378348 @default.
- W2007264108 hasConceptScore W2007264108C30646810 @default.
- W2007264108 hasConceptScore W2007264108C4839761 @default.
- W2007264108 hasConceptScore W2007264108C62520636 @default.
- W2007264108 hasConceptScore W2007264108C71240020 @default.
- W2007264108 hasConceptScore W2007264108C75079739 @default.
- W2007264108 hasConceptScore W2007264108C93391505 @default.
- W2007264108 hasConceptScore W2007264108C97355855 @default.
- W2007264108 hasIssue "9" @default.
- W2007264108 hasLocation W20072641081 @default.
- W2007264108 hasOpenAccess W2007264108 @default.
- W2007264108 hasPrimaryLocation W20072641081 @default.
- W2007264108 hasRelatedWork W1986122429 @default.
- W2007264108 hasRelatedWork W2009211328 @default.
- W2007264108 hasRelatedWork W2022470147 @default.
- W2007264108 hasRelatedWork W2057549993 @default.
- W2007264108 hasRelatedWork W2072856767 @default.
- W2007264108 hasRelatedWork W2080078138 @default.
- W2007264108 hasRelatedWork W2082234425 @default.
- W2007264108 hasRelatedWork W2098059307 @default.
- W2007264108 hasRelatedWork W2128858940 @default.
- W2007264108 hasRelatedWork W2160580913 @default.
- W2007264108 hasVolume "85" @default.
- W2007264108 isParatext "false" @default.
- W2007264108 isRetracted "false" @default.
- W2007264108 magId "2007264108" @default.
- W2007264108 workType "article" @default.