N-苄叉基-1-氨基-萘及其类似物的构象与分子扭曲的共轭驱动力  

The Conformation of N-(phenylmethylene)-2-Naphthaleneamine-Like Species and the π-Driving Force for Distorting Geometry

作　　者：郭彦伸[1] 虞忠衡[1] 金祥林[2] 

机构地区：[1]中国科学院化学研究所,分子动态与稳态结构国家重点实验室,北京100080 [2]北京大学化学与分子工程学院,分子动态与稳态结构国家重点实验室,北京100871

出　　处：《化学学报》2002年第2期228-233,共6页Acta Chimica Sinica

基　　金：国家自然科学基金 (Nos.2 9872 0 42 ;2 0 0 72 0 41;2 0 0 32 0 10 )资助项目

摘　　要：确定了N [(4 二甲基氨基 ) 苄叉基 ] 2 氨基苯并咪唑 (1) ,N [(4 二甲基氨基 ) -苄叉基 ] 2 氨基苯并噻唑 (2 )和N 苄叉基 1 氨基 -萘 (3)的晶体结构 .利用AM1,RHF ,DFT方法和STO 3G ,4 31G ,6 311G及 6 311G 基组 ,优化每个分子的 2 3个扭曲构象 (θ =0°～ - 89°) .尽管不同方法得到的最优构象的扭角不同 ,分子扭曲的驱动力总是起因于电子作用 .在任一分子、任何电子态中 ,离域的π体系总是失稳定的 ,全平面构象不是π体系最稳定的构象 .π电子的离域是分子扭曲的驱动力之一 ,与经典观点相反 ,非键原子间的核排斥作用是分子扭曲的阻力 ,而不是动力 .The crystal structures of N-{[4-(dimethylamino)phenyl]methylene}-2-benzoimidazoleamine (1), N-{[4-(dimethylamino)phenyl]methylene}-2-benzothiazoleamine (2) and N-(phenylmethylene)-2-naphthaleneamine (3) were determined. Twenty-three rotational geometries (θ=0°～ -89°) of each of the molecules were optimized using AM1, RHF/STO-3G, 4-31G, 6-311G, 6-311G ** and B3LYP/4-31G, 6-311G, 6-311G **. The torsional angles of the preferential geometries of compound 1, 2 and 3 are close to the experimental values (1, θ=- 10.69°; 2, θ= -11.99°; 3, θ= -52.88°) in the case of any optimized method. Although different optimized methods provide a specific molecule with different preferential geometries, the electron interaction always favors a twisted geometry and the nuclear repulsion is, practically, a resistance for distortion of the molecule, which is not an artifact of a specific optimized method. The π system in the geometry with θ=0° is most destabilized no matter whether it is delocalized or not. It appears that the π system always prefers a twisted geometry.

关 键 词：共轭效应 构象扭曲驱动力 N-苄叉基-1-氨基-萘 N-[(4-二甲氨基)-苄叉基]-2-氨基苯并噻唑 N-[(4-二甲基氨基)-苄叉基]-2-氨基苯并唑咪唑 

分 类 号：O626[理学—有机化学] O621.1[理学—化学]