Polarization of Aromatic Carbonyl Spectra

Shimada, Ryoichi; Goodman, Lionel

doi:10.1063/1.1697070

Cited by 105 publications

(26 citation statements)

References 30 publications

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“…The present calculations are in good agreement with experiment in terms of energy, intensity and polarization [23] (table 1). Indeed, the agreement between the first six experimental band energies and the first six calculated ~r -->lTr * transition energies is good, but we do not wish to suggest that all these experimental bands arise from 7r-electron transitions.…”

Section: (B) Benzaldehydesupporting

confidence: 91%

A study of the transferability of one and two-centre parameter values in the application of Pariser-Parr-Pople type methods to conjugated carbonyl compounds

Edwards

Grinter

1968

Molecular Physics

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The energies and intensities of the n~ ~r* and ~r~ ~r* transitions of eight conjugated carbonyl compounds, ranging from formaldehyde to 9 : 1 0 -anthraquinone, have been calculated by the Pariser-Parr-Pople method using a set of parameter values which has been used to calculate the n and n-electron ionization potentials of the same molecules. The results for the 7r~ ~r* transitions generally agree well with experiment although the agreement for the larger molecules is better than that for the smaller. Reasons for this are suggested. Calculated singlet-triplet splittings for the n~ rr* transitions agree well with experiment but the calculated absolute energies of then--* l~r* transitions are uniformly 1-2 ev too small. This difference can be removed by giving the lone-pair orbital a new energy basis, and the origin of the discrepancy appears to lie in the approximations of Koopmans's theorem.

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Section: (B) Benzaldehydesupporting

confidence: 91%

A study of the transferability of one and two-centre parameter values in the application of Pariser-Parr-Pople type methods to conjugated carbonyl compounds

Edwards

Grinter

1968

Molecular Physics

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“…The short-lived emitting state is indicative of an mr* triplet; a ' 11' ' 11' * triplet would have a lifetime two to three orders of magnitude longer than the result above. 4 In lO-methylene anthrone the n'll'* absorption region extended to energies lower than 2S 000 em-I. The 0-0 band in the phosphorescence spectrum of this compound was found to be near 25000 em-I.…”

Section: A Polarization Of the Phosphorescence Transition Momentmentioning

confidence: 93%

“…For a "through-space"8 type of interaction involving the direct 9 overlap of the two Py orbitals described by a Hamiltonian H for the two equivalent orbitals, the energies for the combinations given above are (4) where Hij= (Pi 1 HI P j ) and Sij= (Pi 1 Pj). If Iln is taken as the zero of energy, the splitting between the two orbitals <1 is given by…”

Section: A Polarization Of the Phosphorescence Transition Momentmentioning

confidence: 99%

Polarizations of Low Energy Sn← S Transitions in Phthalaldehyde and 10-Methylene Anthrone

Smith

Dearman

1972

The Journal of Chemical Physics

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Articles you may be interested inCharacterization of the minimum energy path for the reaction of singlet methylene with N2: The role of singlet methylene in prompt NOThe polarizations of the transitions to the lowest n1f* and the two lowest 1f1f* transitions of phthalaldehyde have been measured relative to the phosphorescence by the method of photoselection. The polarization of transitions to the lowest lO-methylene anthrone n1f* state and the 1 La and 1 Lv 1f1f* states, which are split by exciton interaction, has also been determined. Molecular orbital calculations, spin-orbit coupling, and considerations of the experimental results indicate that the T1-SO transition of lO-methylene anthrone is polarized along the carbonyl carbon-oxygen bond (Z axis). Application of Platt's spectroscopic moment theory to the lO-methylene anthrone system, considered as two weakly interacting benzene units perturbed by formyl and vinyl substituents, does not account for the observed polarization in the 1f1f* region for a Z-polarized phosphorescence transition moment. The polarization curve in the 1f1f* region is explained on the basis of perturbed 1 La and 1 L" benzene states split by inter-ring exciton interaction. The n1f* transition is believed to be polarized in the molecular plane and perpendicular to the carbonyl axis; that is, along the Y axis. An alternation in polarization in the n1f* region is observed. Indirect evidence is presented which indicates that the T1-SO transition in phthalaldehyde is primarily polarized along the Z axis. If this transition is localized in the formyl groups, a small out-of-plane component of the transition moment may be present since the formyl groups are not expected to be in the molecular plane. The higher 1f1f* transition in phthalaldehyde is polarized parallel to that of the phosphorescence and is assigned to the 1 La~A benzene analog transition. The lower 1f1f* transition is perpendicular and is assigned to the 1 Lv~A transition on the basis of Platt's spectroscopic moment theory. The polarization in the phthalaldehyde n1f* region is uncertain but appears to be polarized in the molecular plane and approximately parallel to the carbonyl carbon-oxygen bond; that is, along the Z axis. The lifetime of the phthalaldehyde phosphorescence was found to be 3 msec.

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“…[9] Several substituted benzophenones display phosphorescence. [10][11][12] Classic syntheses of benzophenones are based on reactions of aryllithium or magnesium reagents with aldehydes and subsequent oxidation and on Friedel-Crafts acylations. [7b,13] For the synthesis of functionalized benzophenones (e.g., containing hydroxy, halide or ester groups), these methods often give unsatisfactory results, due to competing side reactions.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 2′,4‐Diarylbenzophenones through Site‐Selective Suzuki–Miyaura Reactions of Bis(triflates) of 2′,4‐Dihydroxybenzophenones

et al. 2011

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Polarization of Aromatic Carbonyl Spectra

Abstract: Articles you may be interested inOn the magnetic circular dichroism of aromatic carbonyl compounds

Cited by 105 publications

References 30 publications

A study of the transferability of one and two-centre parameter values in the application of Pariser-Parr-Pople type methods to conjugated carbonyl compounds

A study of the transferability of one and two-centre parameter values in the application of Pariser-Parr-Pople type methods to conjugated carbonyl compounds

Polarizations of Low Energy Sn← S Transitions in Phthalaldehyde and 10-Methylene Anthrone

Synthesis of 2′,4‐Diarylbenzophenones through Site‐Selective Suzuki–Miyaura Reactions of Bis(triflates) of 2′,4‐Dihydroxybenzophenones

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