Second hyperpolarizability (γ) of singlet diradical system: Dependence of γ on the diradical character

Masayoshi Nakano, Ryohei Kishi, Tomoshige Nitta, Takashi Kubo, Kazuhiro Nakasuji, Kenji Kamada, Koji Ohta, Benoît Champagne, Edith Botek, Kizashi Yamaguchi

Résultats de recherche: Contribution à un journal/une revueArticle

Résumé

The dependence of the second hyperpolarizability (γ) on the diradical character (γ) for singlet diradical systems is investigated using a model compound, the p-quinodimethane (PQM) molecule with different both-end carbon-carbon (C-C) bond lengths, by several ab initio molecular orbital and density functional theory methods. The diradical character based on UHF calculations indicates that at equilibrium geometry PQM is in a singlet ground state and primarily exhibits a quinoid structure, whereas the diradical character increases when increasing both-end C-C bond lengths. At the highest level of approximation, that is, using the UCCSD(T) method with the 6-31G*+diffuse p (ζ = 0.0523) basis set, the longitudinal static γ of PQM presents a maximum value for intermediate diradical character (y ≈ 0.5) while the γ values are larger for intermediate and large diradical character (y ≈ 0.5-0.7) than for small diradical character (y < 0.2). This feature suggests that the γ values of singlet diradical systems in the intermediate and somewhat strong correlation regimes are significantly enhanced as compared to those in the weak correlation regime. These results are substantiated by a complementary study of the variation in γ upon twisted ethylene.

langue originaleAnglais
Pages (de - à)885-891
Nombre de pages7
journalJournal of physical chemistry A
Volume109
Numéro de publication5
Les DOIs
étatPublié - 10 févr. 2005

Empreinte digitale

Carbon
carbon
Bond length
Molecular orbitals
Ground state
Density functional theory
molecular orbitals
ethylene
density functional theory
Molecules
ground state
Geometry
geometry
approximation
molecules

Citer ceci

Nakano, M., Kishi, R., Nitta, T., Kubo, T., Nakasuji, K., Kamada, K., ... Yamaguchi, K. (2005). Second hyperpolarizability (γ) of singlet diradical system: Dependence of γ on the diradical character. Journal of physical chemistry A, 109(5), 885-891. https://doi.org/10.1021/jp046322x
Nakano, Masayoshi ; Kishi, Ryohei ; Nitta, Tomoshige ; Kubo, Takashi ; Nakasuji, Kazuhiro ; Kamada, Kenji ; Ohta, Koji ; Champagne, Benoît ; Botek, Edith ; Yamaguchi, Kizashi. / Second hyperpolarizability (γ) of singlet diradical system : Dependence of γ on the diradical character. Dans: Journal of physical chemistry A. 2005 ; Vol 109, Numéro 5. p. 885-891.
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title = "Second hyperpolarizability (γ) of singlet diradical system: Dependence of γ on the diradical character",
abstract = "The dependence of the second hyperpolarizability (γ) on the diradical character (γ) for singlet diradical systems is investigated using a model compound, the p-quinodimethane (PQM) molecule with different both-end carbon-carbon (C-C) bond lengths, by several ab initio molecular orbital and density functional theory methods. The diradical character based on UHF calculations indicates that at equilibrium geometry PQM is in a singlet ground state and primarily exhibits a quinoid structure, whereas the diradical character increases when increasing both-end C-C bond lengths. At the highest level of approximation, that is, using the UCCSD(T) method with the 6-31G*+diffuse p (ζ = 0.0523) basis set, the longitudinal static γ of PQM presents a maximum value for intermediate diradical character (y ≈ 0.5) while the γ values are larger for intermediate and large diradical character (y ≈ 0.5-0.7) than for small diradical character (y < 0.2). This feature suggests that the γ values of singlet diradical systems in the intermediate and somewhat strong correlation regimes are significantly enhanced as compared to those in the weak correlation regime. These results are substantiated by a complementary study of the variation in γ upon twisted ethylene.",
author = "Masayoshi Nakano and Ryohei Kishi and Tomoshige Nitta and Takashi Kubo and Kazuhiro Nakasuji and Kenji Kamada and Koji Ohta and Beno{\^i}t Champagne and Edith Botek and Kizashi Yamaguchi",
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Nakano, M, Kishi, R, Nitta, T, Kubo, T, Nakasuji, K, Kamada, K, Ohta, K, Champagne, B, Botek, E & Yamaguchi, K 2005, 'Second hyperpolarizability (γ) of singlet diradical system: Dependence of γ on the diradical character', Journal of physical chemistry A, VOL. 109, Numéro 5, p. 885-891. https://doi.org/10.1021/jp046322x

Second hyperpolarizability (γ) of singlet diradical system : Dependence of γ on the diradical character. / Nakano, Masayoshi; Kishi, Ryohei; Nitta, Tomoshige; Kubo, Takashi; Nakasuji, Kazuhiro; Kamada, Kenji; Ohta, Koji; Champagne, Benoît; Botek, Edith; Yamaguchi, Kizashi.

Dans: Journal of physical chemistry A, Vol 109, Numéro 5, 10.02.2005, p. 885-891.

Résultats de recherche: Contribution à un journal/une revueArticle

TY - JOUR

T1 - Second hyperpolarizability (γ) of singlet diradical system

T2 - Dependence of γ on the diradical character

AU - Nakano, Masayoshi

AU - Kishi, Ryohei

AU - Nitta, Tomoshige

AU - Kubo, Takashi

AU - Nakasuji, Kazuhiro

AU - Kamada, Kenji

AU - Ohta, Koji

AU - Champagne, Benoît

AU - Botek, Edith

AU - Yamaguchi, Kizashi

PY - 2005/2/10

Y1 - 2005/2/10

N2 - The dependence of the second hyperpolarizability (γ) on the diradical character (γ) for singlet diradical systems is investigated using a model compound, the p-quinodimethane (PQM) molecule with different both-end carbon-carbon (C-C) bond lengths, by several ab initio molecular orbital and density functional theory methods. The diradical character based on UHF calculations indicates that at equilibrium geometry PQM is in a singlet ground state and primarily exhibits a quinoid structure, whereas the diradical character increases when increasing both-end C-C bond lengths. At the highest level of approximation, that is, using the UCCSD(T) method with the 6-31G*+diffuse p (ζ = 0.0523) basis set, the longitudinal static γ of PQM presents a maximum value for intermediate diradical character (y ≈ 0.5) while the γ values are larger for intermediate and large diradical character (y ≈ 0.5-0.7) than for small diradical character (y < 0.2). This feature suggests that the γ values of singlet diradical systems in the intermediate and somewhat strong correlation regimes are significantly enhanced as compared to those in the weak correlation regime. These results are substantiated by a complementary study of the variation in γ upon twisted ethylene.

AB - The dependence of the second hyperpolarizability (γ) on the diradical character (γ) for singlet diradical systems is investigated using a model compound, the p-quinodimethane (PQM) molecule with different both-end carbon-carbon (C-C) bond lengths, by several ab initio molecular orbital and density functional theory methods. The diradical character based on UHF calculations indicates that at equilibrium geometry PQM is in a singlet ground state and primarily exhibits a quinoid structure, whereas the diradical character increases when increasing both-end C-C bond lengths. At the highest level of approximation, that is, using the UCCSD(T) method with the 6-31G*+diffuse p (ζ = 0.0523) basis set, the longitudinal static γ of PQM presents a maximum value for intermediate diradical character (y ≈ 0.5) while the γ values are larger for intermediate and large diradical character (y ≈ 0.5-0.7) than for small diradical character (y < 0.2). This feature suggests that the γ values of singlet diradical systems in the intermediate and somewhat strong correlation regimes are significantly enhanced as compared to those in the weak correlation regime. These results are substantiated by a complementary study of the variation in γ upon twisted ethylene.

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U2 - 10.1021/jp046322x

DO - 10.1021/jp046322x

M3 - Article

AN - SCOPUS:13444292427

VL - 109

SP - 885

EP - 891

JO - The journal of physical chemistry. A

JF - The journal of physical chemistry. A

SN - 1089-5639

IS - 5

ER -