The electronic spectrum of the tropone molecule

Yamaguchi, Hiroyuki; Amako, Yoshito; Azumi, Hiroshi

doi:10.1016/0040-4020(68)89028-3

Cited by 19 publications

(3 citation statements)

References 13 publications

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“…Besides this fluorescence, no phosphorescence has been observed from tropolone at 77 K. According to our energy transfer experiments, its lowest triplet state lies at 201 kJ/mol (-48 kcal/mol). This agrees well with the cklculations for tropone (which is tropolone minus the OH group) predicting a value of 184209 kJ/mol (44-50 kcal/mol) (Yamaguchi et al, 1968) and also with the sensitization experiments giving 172 < ET, < 222 kJ/mol (Turro et al, 1969). The triplet state is well below the lowest singlet state (AE, -lo4 cm-l) and this means that it has a n,n* nature.…”

Section: Tropolonesupporting

confidence: 87%

Photophysical Processes in Tropolone, Α‐methoxy‐tropone and Colchicine

Croteau

Leblanc

1978

Photochem & Photobiology

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Abstract— The spectral characteristics of the emission observed from tropolone, α‐methoxy‐tropone and colchicine in EPA at 77 K are reported. Luminescence polarization, lifetime, quantum yield and energy transfer experiments provide evidence that the luminescence observed is S1→ S0 fluorescence and that the lowest excited singlet state is π, π* The two compounds α‐methoxy‐tropone and colchicine have been found to exhibit dual luminescence. No phosphorescence could be detected in these three molecules. The photophysical processes for each molecule are discussed and their respective energy level diagrams are also suggested.

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Section: Tropolonesupporting

confidence: 87%

Photophysical Processes in Tropolone, Α‐methoxy‐tropone and Colchicine

Croteau

Leblanc

1978

Photochem & Photobiology

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“…Im Gegcnsatz dazu haben Untersuchungen von TANIZAKI und Mitarbeitern [14] an gereckten Polyathylenfolien, in welchen Tropon gelost worden war, die von uns vorgeschlagene Zuordnung bestatigt. Die im Anschluss daran durch YAMA-GUCHI, AZUMI, AMAKO und AZUMI [15] durchgefuhrten theoretischen Berechnungen lieferten, analog zu den fruher [l] und in dieser Arbeit erhaltenen Resultaten, eine Erklarung dieses Sachverhaltes, indem die beiden der Iangstwelligen Bande von I entsprechenden ubergange als vom n -+ n*-Typus gedeutet werden. Wie gezeigt, weisen auch die hier angefiihrten Messungen und ihre modellmassige Reschreibung in dieser Richtung2).…”

Section: Vevgleich Der Experimentellen Und Theoretisch Berechneten unclassified

Das Elektronenspektrum eines vinylogen Tropons (Die photochemische darstellung des 2‐Hydroxy‐guaj‐azulens)

Hagen¹,

Heilbronner²,

Straub³

1967

Helvetica Chimica Acta

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Irradiation of guaj‐azulene‐2‐sulfonic acid (VII) in 40 percent aqueous or methanolic sulfuric acid with light of 370 nm wave‐length yields 2‐hydroxy‐guaj‐azulene (V) or 2‐methoxy‐guaj‐azulene (X) respectively. The former compound (V) exhibits a keto‐enol tautomerism V ⇋ VI, the equilibrium constant of which is strongly dependent on solvent. The keto form VI contains the π‐electron system of a vinylogue tropone IV. The theoretical analysis of the electronic spectrum of VI, using a CI‐model of the PARISER‐PARR‐POPLE type, supports the previously proposed assignement of the electronic transitions observed in tropone (I), benzotropone (II) and naphthotropone (III).

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“…With the geometry obtained by the MNDO method [28], we calculated the molecular-orbital energies by using PPP MO method [13]. With an increase of the Coulomb integral of the terminal C-atom of heptafulvene, the two transitions, corresponding to the bands 430 nm (perpendicular) and 280 nm (parallel), first approach each other (in the case of tropone) [7] …”

mentioning

confidence: 99%