FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1985457540> ?p ?o ?g. }

• W1985457540 endingPage "679" @default.
• W1985457540 startingPage "673" @default.
• W1985457540 abstract "Irradiation of all-trans-1,6-diphenyl-1,3,5-hexatriene (ttt-DPH) in degassed acetonitrile (AN) gives ctt- and tct-DPH, relatively inefficiently, mainly via isomerization in the singlet excited state. The triplet contribution to the photoisomerization is small due to a very low intersystem crossing yield (ϕ is = 0.01). Central bond isomerization is quenched in the presence of air by a factor of 1.4, consistent with the expected quenching of the lowest singlet and triplet excited states by oxygen. However, the presence of air enhances terminal bond photoisomerization by nearly twofold. Triplet-sensitized ttt-DPH photoisomerization favors tct-DPH formation and is quenched by oxygen. It follows that the interaction of singlet-excited ttt-DPH with O 2 suppresses isomerization to tct-DPH but opens a new isomerization pathway to ctt-DPH. The presence of dimethylfuran, a singlet O 2 trap, has no effect on the photoisomerization, eliminating the possible involvement of singlet O 2 in this new reaction. ttt-DPH radical cations are ruled out as intermediates because the presence of fumaronitrile, which leads to their formation, suppresses both central and terminal bond photoisomerizations. In contrast to acetonitrile, ctt-DPH formation is quenched by oxygen in methylcyclohexane, suggesting the requirement of a polar environment. Strikingly different deuterium isotope effects distinguish the direct and O 2 -induced photoisomerization pathways. A comparative study of ttt-DPH-d 0 with ttt-DPH-d 2 and ttt-DPH-d 4 , involving deuteration of one and both terminal double bonds, reveals an inverse kinetic isotope effect (k H ox /k D ox = 0.92) for the O 2 -induced reaction. An attractive mechanism for the new oxygen-induced photoisomerization involves charge transfer from the S 1 state of ttt-DPH to oxygen followed by collapse of the exciplex to either a zwitterionic or a biradicaloid species through bonding at one of the benzylic positions. Rotation about the new single bond in this intermediate followed by reversion to DPH and O 2 gives the observed result. Key words: diphenylhexatrienes, trans-cis photoisomerization, oxygen sensitization." @default.
• W1985457540 created "2016-06-24" @default.
• W1985457540 creator A5001352589 @default.
• W1985457540 creator A5018465488 @default.
• W1985457540 creator A5060725119 @default.
• W1985457540 creator A5085988588 @default.
• W1985457540 creator A5088915129 @default.
• W1985457540 date "2003-06-01" @default.
• W1985457540 modified "2023-10-17" @default.
• W1985457540 title "Stereoselective O₂-induced photoisomerization of all-<i>trans</i>-1,6-diphenyl-1,3,5-hexatriene" @default.
• W1985457540 cites W1964620004 @default.
• W1985457540 cites W1968701949 @default.
• W1985457540 cites W1970095664 @default.
• W1985457540 cites W1976233373 @default.
• W1985457540 cites W1983095875 @default.
• W1985457540 cites W1984205486 @default.
• W1985457540 cites W1985247979 @default.
• W1985457540 cites W1989470850 @default.
• W1985457540 cites W1995199197 @default.
• W1985457540 cites W1997409282 @default.
• W1985457540 cites W1997675250 @default.
• W1985457540 cites W1999090693 @default.
• W1985457540 cites W2010006302 @default.
• W1985457540 cites W2017153549 @default.
• W1985457540 cites W2029782443 @default.
• W1985457540 cites W2031331776 @default.
• W1985457540 cites W2034915383 @default.
• W1985457540 cites W2046822386 @default.
• W1985457540 cites W2048108762 @default.
• W1985457540 cites W2055061321 @default.
• W1985457540 cites W2055533268 @default.
• W1985457540 cites W2057707604 @default.
• W1985457540 cites W2060986534 @default.
• W1985457540 cites W2067344978 @default.
• W1985457540 cites W2067643464 @default.
• W1985457540 cites W2071948257 @default.
• W1985457540 cites W2082425547 @default.
• W1985457540 cites W2093206013 @default.
• W1985457540 cites W2118123167 @default.
• W1985457540 cites W2139204833 @default.
• W1985457540 cites W2141919881 @default.
• W1985457540 cites W2180075714 @default.
• W1985457540 cites W2319338610 @default.
• W1985457540 cites W2325934748 @default.
• W1985457540 cites W2949133573 @default.
• W1985457540 cites W3005250904 @default.
• W1985457540 doi "https://doi.org/10.1139/v03-082" @default.
• W1985457540 hasPublicationYear "2003" @default.
• W1985457540 type Work @default.
• W1985457540 sameAs 1985457540 @default.
• W1985457540 citedByCount "6" @default.
• W1985457540 crossrefType "journal-article" @default.
• W1985457540 hasAuthorship W1985457540A5001352589 @default.
• W1985457540 hasAuthorship W1985457540A5018465488 @default.
• W1985457540 hasAuthorship W1985457540A5060725119 @default.
• W1985457540 hasAuthorship W1985457540A5085988588 @default.
• W1985457540 hasAuthorship W1985457540A5088915129 @default.
• W1985457540 hasConcept C121332964 @default.
• W1985457540 hasConcept C121745418 @default.
• W1985457540 hasConcept C126661725 @default.
• W1985457540 hasConcept C161790260 @default.
• W1985457540 hasConcept C178790620 @default.
• W1985457540 hasConcept C181500209 @default.
• W1985457540 hasConcept C185544564 @default.
• W1985457540 hasConcept C185592680 @default.
• W1985457540 hasConcept C2777516457 @default.
• W1985457540 hasConcept C32909587 @default.
• W1985457540 hasConcept C33062035 @default.
• W1985457540 hasConcept C540031477 @default.
• W1985457540 hasConcept C58364064 @default.
• W1985457540 hasConcept C62520636 @default.
• W1985457540 hasConcept C68381374 @default.
• W1985457540 hasConcept C69928629 @default.
• W1985457540 hasConcept C71240020 @default.
• W1985457540 hasConcept C73978554 @default.
• W1985457540 hasConcept C75079739 @default.
• W1985457540 hasConcept C75473681 @default.
• W1985457540 hasConcept C76766466 @default.
• W1985457540 hasConcept C85311670 @default.
• W1985457540 hasConcept C91881484 @default.
• W1985457540 hasConceptScore W1985457540C121332964 @default.
• W1985457540 hasConceptScore W1985457540C121745418 @default.
• W1985457540 hasConceptScore W1985457540C126661725 @default.
• W1985457540 hasConceptScore W1985457540C161790260 @default.
• W1985457540 hasConceptScore W1985457540C178790620 @default.
• W1985457540 hasConceptScore W1985457540C181500209 @default.
• W1985457540 hasConceptScore W1985457540C185544564 @default.
• W1985457540 hasConceptScore W1985457540C185592680 @default.
• W1985457540 hasConceptScore W1985457540C2777516457 @default.
• W1985457540 hasConceptScore W1985457540C32909587 @default.
• W1985457540 hasConceptScore W1985457540C33062035 @default.
• W1985457540 hasConceptScore W1985457540C540031477 @default.
• W1985457540 hasConceptScore W1985457540C58364064 @default.
• W1985457540 hasConceptScore W1985457540C62520636 @default.
• W1985457540 hasConceptScore W1985457540C68381374 @default.
• W1985457540 hasConceptScore W1985457540C69928629 @default.
• W1985457540 hasConceptScore W1985457540C71240020 @default.
• W1985457540 hasConceptScore W1985457540C73978554 @default.

• next