Semiempirical Scf–lcao–mo Treatment of Thiophene, Furan, and Pyrrole

Solony, N.; Birss, F. W.; Greenshields, J. B.

doi:10.1139/v65-208

Cited by 66 publications

(7 citation statements)

References 20 publications

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“…In terms of electron density and free valence number, the enhanced reactivity of the thienyl substituent over that of phenyl can be viewed, rather naively, as a reflection of the fact that only five atoms are sharing the π-electrons of the aromatic sextet and quantitative yields of reaction are often observed, as in the case of the transformation of 1,2-bis(thiophene-2-yl)ethene into thieno[3,2- e ]benzo[ b ]thiophene …”

Section: Discussionmentioning

confidence: 99%

Synthesis of New Sulfur Heteroaromatics Isoelectronic with Dibenzo[g,p]chrysene by Photocyclization of Thienyl- and Phenyl-Substituted Ethenes

et al. 1996

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A series of new sulfur heteroarenes, isoelectronic with dibenzo[g,p]chrysene, have been prepared by double photocyclization of the corresponding tetraaryl substituted ethenes. The first step proceeds efficiently in each case, and the corresponding intermediate sulfur heteroarenes, isoelectronic with phenanthrene, have been isolated. The second ring closure is only efficient when one of the participating aryl substituents is thienyl, which thus manifests a higher electron density on the carbon atom involved in the excited singlet state reaction. Most of the new compounds are of minimal solubility in common solvents and do not display improved electron donor properties otherwise commonly found among heteroaromatics.

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Section: Discussionmentioning

confidence: 99%

Synthesis of New Sulfur Heteroaromatics Isoelectronic with Dibenzo[g,p]chrysene by Photocyclization of Thienyl- and Phenyl-Substituted Ethenes

et al. 1996

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“…A modified Pople-Pariser-Parr procedure has also been successfully applied to the calculation of the electronic spectra of 2-and 3-nitropyrrole. The first procedure, developed by ( 8 4 ) Brown (81) Lykos (85) Dahl ( 8 6 ) Julg (87) Leroy (88) Solony (89) Chiorboli (80) Evleth (91) Flurry (92) Kunii (93) Adams ( 8 3 ) Bloor (77) Zahradnik (94) DelRe (95) Allinger (96 > Aussems (97) p u j 0 l(98, Hirota ( DelRe, treats the σ-bonds as localized bonds. The first procedure, developed by ( 8 4 ) Brown (81) Lykos (85) Dahl ( 8 6 ) Julg (87) Leroy (88) Solony (89) Chiorboli (80) Evleth (91) Flurry (92) Kunii (93) Adams ( 8 3 ) Bloor (77) Zahradnik (94) DelRe (95) Allinger (96 > Aussems (97) p u j 0 l(98, Hirota ( DelRe, treats the σ-bonds as localized bonds.…”

Section: Scf π-Electron Calculationsmentioning

confidence: 99%

The Structure and Reactivity of Pyrrole

1977

The Chemistry of Pyrroles

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“…29 Semi-empirical calculations have not been able to provide a clear picture of the electronic spectrum. [30][31][32][33][34] While theoretical studies on thiophene molecule reported are based on ab initio quantum chemical approach, [35][36][37] due to its large size, similar studies on PT is difficult using these methods. Restricted configuration interaction (CI) technique is also not useful for solving these interacting systems as we need to extrapolate the results to the polymer limit and restricted CI calculation are not size consistent.…”

Section: Introductionmentioning

confidence: 99%

A density matrix renormalization group study of low-lying excitations of polythiophene within a Pariser-Parr-Pople model

Das

Ramasesha

2006

J Chem Sci

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Symmetrized density-matrix-renormalization-group calculations have been carried out, within Pariser-Parr-Pople Hamiltonian, to explore the nature of the ground and low-lying excited states of long polythiophene oligomers. We have exploited C 2 symmetry and spin parity of the system to obtain excited states of experimental interest, and studied the lowest dipole allowed excited state and lowest dipole forbidden two photon state, for different oligomer sizes. In the long system limit, the dipole allowed excited state always lies below the lowest dipole forbidden two-photon state which implies, by Kasha rule, that polythiophene fluoresces strongly. The lowest triplet state lies below two-photon state as usual in conjugated polymers. We have doped the system with a hole and an electron and obtained the charge excitation gap and the binding energy of the 1 1 B u exciton. We have calculated the charge density of the ground, one-photon and two-photon states for the longer system size of 10 thiophene rings to characterize these states. We have studied bond order in these states to get an idea about the equilibrium excited state geometry of the system. We have also studied the charge density distribution of the singly and doubly doped polarons for longer system size, and observe that polythiophenes do not support bipolarons.

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Semiempirical Scf–lcao–mo Treatment of Thiophene, Furan, and Pyrrole

Cited by 66 publications

References 20 publications

Synthesis of New Sulfur Heteroaromatics Isoelectronic with Dibenzo[g,p]chrysene by Photocyclization of Thienyl- and Phenyl-Substituted Ethenes

Synthesis of New Sulfur Heteroaromatics Isoelectronic with Dibenzo[g,p]chrysene by Photocyclization of Thienyl- and Phenyl-Substituted Ethenes

The Structure and Reactivity of Pyrrole

A density matrix renormalization group study of low-lying excitations of polythiophene within a Pariser-Parr-Pople model

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