Photoelectron and ultraviolet spectra of small-ring fused aromatic molecules as probes of aromatic ring distortions

Santiago, Cielo; Gandour, Ruth Wells; Houk, K. N.; Nutakul, Wutichai; CRAVEY, W. E.; Thummel, Randolph P.

doi:10.1021/ja00480a013

Cited by 39 publications

(10 citation statements)

References 9 publications

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“…Thus 43, biscyclobuta[a,c]benzene and prehnitene (1,2,3,4-tetramethylbenzene) have very similar absorption maxima. This dichotomy of behavior has been rationalized (121) for the biscyclobutabenzenes and results from the hyperconjugative abilities of the fused rings and changes in the configurational composition of the lowest excited singlet state. The infrared spectra of the cycloproparenes are simple and reflect the symmetry of the molecules.…”

Section: -Oxocycloproparenesmentioning

confidence: 97%

The Cycloproparenes

Halton¹

1980

Ind. Eng. Chem. Prod. Res. Dev.

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Section: -Oxocycloproparenesmentioning

confidence: 97%

The Cycloproparenes

Halton¹

1980

Ind. Eng. Chem. Prod. Res. Dev.

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“…For indan, the theory predicts 8.15 (π) and 8.49 (π) eV and the experimental values are 8.46 and 9.04 eV. 28 Therefore, the theoretical formalism employed here suffers from an underestimation of the top phenyl π S,A E i 's, whereas it reproduces the n and π CO E i 's more satisfactorily. To settle the specific assignments of 1-6, the theoretical E i 's associated with the uppermost phenyl π S,A MOs were, therefore, raised by an average shift of 0.27 eV (i.e., the difference quoted for benzene).…”

Section: Resultsmentioning

confidence: 79%

“…For benzaldehyde, the theory predicts 9.28 (π), 9.38 (π), 9.84 (n), 12.16 (σ), 12.37 (π CO ), and 12.61 (σ) eV, and the experiment yields E i 's of 9.4 (π), 9.57 (n), 9.75 (π), 12.17 (σ), 12.47 (π CO ), and 12.82 (σ) eV. For indan, the theory predicts 8.15 (π) and 8.49 (π) eV and the experimental values are 8.46 and 9.04 eV . Therefore, the theoretical formalism employed here suffers from an underestimation of the top phenyl π S,A E i 's, whereas it reproduces the n and π CO E i 's more satisfactorily.…”

Section: Resultsmentioning

confidence: 88%

On the Molecular and Electronic Structure of Spiroketones and Half-Molecule Models

Galasso¹,

Bogdanov²,

Maslak³

et al. 2002

J. Phys. Chem. A

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The equilibrium structures of three polyketones based on the 2,2‘-spirobiindan skeleton (1,1‘-dione, 1,3,1‘-trione, and 1,3,1‘,3‘-tetraone), their “half-molecule” fragments (1-indanone and 2,2-dimethylindan-1,3-dione), and the indandione dimer (2,2‘-dimethyl-[2,2‘]-biindenyl-1,3,1‘,3‘-tetraone) were investigated using the density functional theory model B3LYP/6-31G(d,p). The results matched the X-ray experimental data that are available for one of the spiroketones. The electronic structure of these ketones was investigated by means of their spectroscopic properties. The NMR 13C chemical shifts, calculated by the continuous-set-of-gauge-transformations formalism with the B3LYP/6-311+G(2d,p) method, were fairly consistent with NMR observations, in particular for the carbonyl, spiro, and quaternary carbons. The He(I) photoelectron spectra were measured and interpreted by means of ab initio outer-valence-Green's-function calculations. The theoretical results consistently reproduced the energies and splittings of the uppermost bands. These bands were associated with the phenyl π orbitals and the n(CO) lone-pair orbitals of the keto groups. Electron transmission spectroscopy, with the support of calculated π* virtual orbital energies, was employed to characterize the empty levels. Strong mixing between the phenyl and carbonyl π* fragment orbitals gave rise to stable anion states. Temporary anion states with mainly carbonyl character were observed in the 1.5−2.5 eV energy range. In the spiroketones, their energy splittings increase with the number of carbonyl groups present in the molecules and indicate the occurrence of through-space interactions between the two perpendicular indan halves.

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“…These phenomena are compatible with the abilities of the alicyclic rings to be involved in hyperconjugation and with changes in the configurational composition of the lowest excited state. 4,5,177 The UV spectra of the colored alkylidenecycloproparenes 149-153 show long-wavelength absorption maxima, the positions of which are solvent dependent in accord with the observed polarities.139,141 Some of the compounds exhibit strong fluorescence as has been noted in section IV.B. The infrared spectra of the cycloproparenes and their alkylidene derivatives are comparatively simple and reflect the symmetry of the systems.…”

Section: Table IV Heats Of Formation and Strain Energies Ofmentioning

confidence: 77%

Developments in cycloproparene chemistry

Halton¹

1989

Chem. Rev.

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Photoelectron and ultraviolet spectra of small-ring fused aromatic molecules as probes of aromatic ring distortions

Cited by 39 publications

References 9 publications

The Cycloproparenes

The Cycloproparenes

On the Molecular and Electronic Structure of Spiroketones and Half-Molecule Models

Developments in cycloproparene chemistry

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