Kato Takashi, Yamabe Tokio
Fukui Institute for Fundamental Chemistry, Kyoto University, 34-4 Takano-Nishihiraki-cho, Sakyo-ku, Kyoto 606-8103, Japan.
J Chem Phys. 2004 Jul 1;121(1):501-9. doi: 10.1063/1.1755671.
Electron-phonon interactions in the monoanions of B, N-substituted acenes such as B(3)N(3)F(6) (1f) and B(5)N(5)F(8) (2f) are studied, and compared with those in the monoanions of B(3)N(3)H(6) (1h) and B(5)N(5)H(8) (2h), and B(3)N(3)D(6) (1d) and B(5)N(5)D(8) (2d). The low frequency modes around 500 cm(-1) as well as the frequency modes higher than 1000 cm(-1) strongly couple to the lowest unoccupied molecular orbitals (LUMO) in 1f and 2f. The total electron-phonon coupling constants (l(LUMO)) are estimated to be 2.710 and 2.054 eV for 1f and 2f, respectively, and those are estimated to be 0.342 and 0.235 eV for 1d and 2d, respectively, while those were estimated to be 0.340 and 0.237 eV for 1h and 2h, respectively. That is, the l(LUMO) value increases much more significantly by H-F substitution than by H-D substitution in B, N-substituted acenes. The larger displacements of B and N atoms in the vibronic active modes in 1f and 2f than those in 1d and 2d due to larger atomic mass of fluorine than that of deuterium, and the phase patterns difference between the LUMO in 1f and 2f, in which the atomic orbitals between N and its neighboring F atoms form strong sigma-antibonding interactions, and that in 1d and 2d, in which the atomic orbitals between two neighboring B and N atoms form weak pi-bonding and pi-antibonding interactions, are the main reason why the l(LUMO) value increases much more significantly by H-F substitution than by H-D substitution. The reorganization energies between the neutral molecules and the corresponding monoanions are estimated to be 0.122, 0.063, 0.733, and 0.830 eV for 1h, 2h, 1f, and 2f, respectively. Therefore, the estimated reorganization energies between the neutral molecules and the corresponding monoanions for 1f and 2f are much larger than those for 1h and 2h.
研究了硼氮取代并苯单阴离子（如B(3)N(3)F(6) (1f)和B(5)N(5)F(8) (2f)）中的电子 - 声子相互作用，并将其与B(3)N(3)H(6) (1h)和B(5)N(5)H(8) (2h)以及B(3)N(3)D(6) (1d)和B(5)N(5)D(8) (2d)的单阴离子中的相互作用进行了比较。1f和2f中500 cm(-1)左右的低频模式以及高于1000 cm(-1)的频率模式与最低未占据分子轨道（LUMO）强烈耦合。1f和2f的总电子 - 声子耦合常数（l(LUMO)）分别估计为2.710和2.054 eV，1d和2d的分别估计为0.342和0.235 eV，而1h和2h的分别估计为0.340和0.237 eV。也就是说，在硼氮取代并苯中，H - F取代比H - D取代使l(LUMO)值增加得更显著。由于氟的原子质量大于氘，1f和2f中振动活性模式下硼和氮原子的位移比1d和2d中的大，并且1f和2f中LUMO的相位模式不同（其中氮与其相邻氟原子之间的原子轨道形成强σ反键相互作用），而1d和2d中相邻硼和氮原子之间的原子轨道形成弱π键和π反键相互作用，这是H - F取代比H - D取代使l(LUMO)值增加得更显著的主要原因。1h、2h、1f和2f的中性分子与相应单阴离子之间的重组能分别估计为0.122、0.063、0.733和0.830 eV。因此，1f和2f的中性分子与相应单阴离子之间的估计重组能比1h和2h的大得多。
