Theoretical study of the valence π→π* excited states of polyacenes: Benzene and naphthalene

Multireference perturbation theory with complete active space self‐consistent field (CASSCF) reference functions was applied to the study of the valence π→π* excited states of benzene and naphthalene. The eigenvectors and eigenvalues of CASSCF with valence π active orbitals satisfy pairing properties for the alternant hydrocarbons to a good approximation. The excited states of polyacenes are classified into the covalent minus states and ionic plus states with the use of the alternancy symmetry. The present theory satisfactorily describes the ordering of low‐lying valence π→π* excited states. The overall accuracy of the present approach is surprisingly high. We were able to predict the valence excitation energies with an accuracy of 0.27 eV for singlet u states and of 0.52 eV or better for singlet g states of naphthalene. Our predicted triplet states spectrum provides a consistent assignment of the triplet–triplet absorption spectrum of naphthalene. For benzene we were able to predict the valence excitatio...

[1]  B. Dick,et al.  Two‐photon spectroscopy of dipole‐forbidden transitions. II. Calculation of two‐photon cross sections by the CNDO–CI method , 1979 .

[2]  E. Hückel,et al.  Quanstentheoretische Beiträge zum Benzolproblem , 1931 .

[3]  G. C. Morris,et al.  Interference effects in the optical spectrum of large molecules , 1969 .

[4]  J. Pople,et al.  Electron interaction in unsaturated hydrocarbons , 1953 .

[5]  H. B. Klevens,et al.  Spectral Resemblances of Cata‐Condensed Hydrocarbons , 1949 .

[6]  J. P. Doering,et al.  Low‐Energy Electron‐Impact Study of the First, Second, and Third Triplet States of Benzene , 1969 .

[7]  A. Bree,et al.  The crystal spectrum of naphthalene in the region 3200 Å to 2200 Å , 1962 .

[8]  J. Hollas,et al.  Band contour analyses of the spectra of asymmetric rotor molecules: Part III. The 3200-Å absorption of napthalene , 1965 .

[9]  S. M. Cameron,et al.  Characterization of excited electronic states of naphthalene by resonance Raman and hyper‐Raman scattering , 1992 .

[10]  H. Nakano,et al.  Multireference Møller-Plesset perturbation treatment for valence and Rydberg excited states of benzene , 1995 .

[11]  B. Mangum,et al.  PARAMAGNETIC RESONANCE ABSORPTION IN NAPHTHALENE IN ITS PHOSPHORESCENT STATE , 1958 .

[12]  B. Roos,et al.  A complete active space SCF method (CASSCF) using a density matrix formulated super-CI approach , 1980 .

[13]  B. Roos,et al.  Towards an accurate molecular orbital theory for excited states: the benzene molecule , 1992 .

[14]  Nobuaki Nakashima,et al.  Laser flash photolysis of benzene. III. Sn←S1 absorption of gaseous benzene , 1980 .

[15]  M. Allan.  Study of triplet states and short-lived negative ions by means of electron impact spectroscopy , 1989 .

[16]  E. Koch,et al.  The vacuum ultraviolet spectrum of naphthalene vapour for photon energies from 5 to 30 eV , 1972 .

[17]  R. Astier,et al.  Triplet‐Triplet Spectroscopy of Polyacenes , 1972 .

[18]  Collective Oscillations in Pure Liquid Benzene , 1969 .

[19]  G. Fischer,et al.  Triplet-triplet spectra of aromatic molecules in mixed crystals , 1967 .

[20]  Haruyuki Nakano,et al.  Quasidegenerate perturbation theory with multiconfigurational self‐consistent‐field reference functions , 1993 .

[21]  H. Hunziker.  Gas‐Phase Absorption Spectrum of Triplet Naphthalene in the 220–300‐nm and 410–620‐nm Wavelength Regions , 1972 .

[22]  T. Pavlopoulos.  Search for the First 3A1g− ← 3B2u+ Transition in Naphthalene , 1970 .

[23]  S. J. Strickler,et al.  A priori calculations on vibronic coupling in the 1B2u 1Ag (3200 Å) and higher transitions of naphthalene , 1977 .

[24]  H. Nakatsuji,et al.  Cluster expansion of the wavefunction: Ionizations and some low-energy excitations of naphthalene , 1987 .

[25]  J. Cizek,et al.  Correlation effects in the low–lying excited states of the PPP models of alternant hydrocarbons. I. Qualitative rules for the effect of limited configuration interaction , 1974 .

[26]  R. Astier,et al.  First allowed triplet-triplet transition in benzene , 1969 .

[27]  C. Kuyatt,et al.  Electron energy-loss spectroscopy of naphthalene vapor☆ , 1972 .

[28]  A. Hiraya,et al.  Direct absorption spectra of jet-cooled benzene in 130-260 nm , 1991 .

[29]  K. Man,et al.  Excitation of naphthalene by electron impact , 1992 .

[30]  Rudolph Pariser,et al.  Theory of the Electronic Spectra and Structure of the Polyacenes and of Alternant Hydrocarbons , 1956 .

[31]  A. Sklar,et al.  Calculations of the Lower Excited Levels of Benzene , 1938 .

[32]  C. A. Coulson,et al.  Note on the method of molecular orbitals , 1940, Mathematical Proceedings of the Cambridge Philosophical Society.

[33]  M. El-Sayed,et al.  Polarization of the Triplet—Triplet Absorption Spectrum of Some Polyacenes by the Method of Photoselection , 1963 .

[34]  E. N. Lassettre,et al.  HIGH-RESOLUTION STUDY OF ELECTRON-IMPACT SPECTRA AT KINETIC ENERGIES BETWEEN 33 AND 100 eV AND SCATTERING ANGLES TO 16--. , 1968 .

[35]  S. Rice,et al.  Interference Effects in the Rydberg Spectra of Naphthalene and Benzene , 1972 .

[36]  Kimihiko Hirao,et al.  Multireference Møller–Plesset perturbation treatment of potential energy curve of N2 , 1992 .

[37]  C. Coulson.  Excited Electronic Levels in Conjugated Molecules: I. Long Wavelength Ultra-Violet Absorption of Naphthalene, Anthracene and Homologs , 1948 .

[38]  H. Hunziker.  Formation of triplet naphthalene by energy transfer from Hg(63P0 atoms, observed by a modulation technique , 1969 .

[39]  Taiji Kitagawa.  Absorption spectra and photoionization of polycyclic aromatics in vacuum ultraviolet region , 1968 .

[40]  J. Koutecký.  Contribution to the Theory of Alternant Systems , 1966 .

[41]  M. Palmer,et al.  The electronic states of benzene and the azines. I. The parent compound benzene. Correlation of vacuum UV and electron scattering data with ab initio CI studies , 1989 .

[42]  B. Dick,et al.  TWO-PHOTON SPECTROSCOPY OF THE LOW-LYING SINGLET STATES OF NAPHTHALENE AND ACENAPHTHENE , 1981 .

[43]  P. Swiderek,et al.  Electron energy loss spectroscopy of solid naphthalene and acenaphthene: search for the low-lying triplet states , 1990 .

[44]  H. Nakatsuji,et al.  Cluster expansion of the wave function. Valence and Rydberg excitations and ionizations of benzene , 1984 .

[45]  Hans-Joachim Werner,et al.  A quadratically convergent multiconfiguration–self‐consistent field method with simultaneous optimization of orbitals and CI coefficients , 1980 .

[46]  G. C. Morris,et al.  The intensity of absorption of naphthalene from 30 000 cm−1 to 53 000 cm−1 , 1968 .

[47]  K. Hirao,et al.  Study of low‐lying electronic states of ozone by multireference Mo/ller–Plesset perturbation method , 1995 .

[48]  N. Mikami,et al.  Two-photon excitation spectra of naphthalene and naphthalene-d8 , 1975 .

[49]  T. H. Dunning.  Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen , 1989 .

[50]  G. W. Robinson,et al.  Exciton Structure in Two Triplet States of Crystalline Naphthalene , 1965 .