Departmental Bulletin Paper ベンゾエートアニオンの気相安定性に及ぼす置換基効果の二面角依存性

中田, 和秀  ,  藤尾, 瑞枝

Relative gas-phase stabilities of ring-substituted benzoate anions, of which the dihedral angle φ between the benzene ring and the COO – planes was fixed, were computationally determined utilizing isodesmic reactions. The energies of respective species involved in the reactions were calculated by B3LYP/6-311+G(2d,p) level of theory. The φ was varied from 0˚ to 90˚ by steps of 10˚. Obtained 10 kinds of substituent effects were analyzed by an extended Yukawa-Tsuno equation: –Δ E X =ρ (σ 0 + r − Δσ R − + s Δσ S Resultant r – value increased from -0.03 (φ=0˚) to 0.38 (φ=90˚) with the increase of the φ. To reveal the mechanism of the through-resonance in benzoate anions, NBO analyses were performed. It has become apparent that the donation of electrons from the lone pairs on the O atoms to the benzene π-electron system is crucial to the through-resonance in twisted benzoate anions. Keywords : Substituent Effect, Benzoate Anion, Extended Yukawa-Tsuno Equation, DFT calculation, NBO Analysis

Number of accesses :  

Other information