that of 1-(arylselanyl)anthraquinones (3 (pd)). Sets of delta(Se) of 1 and 2 must serve as the standard for pl and that of 3 does for pd in solutions. Structures of various ArSeR in solutions are determined from the viewpoint of the orientational effect based on the standard delta(Se) of 1-3. While the structure of 2-methyl-1-(arylselanyl)naphthalenes is concluded to be all pl in solutions, those of 8-chloro-
提出了一组新的delta(Se)参数,作为ArSeR中p-YC(6)H(4)(Ar)的平面(pl)取向效应的标准,采用9-(芳基
硒基)三联烯(1:p -YC(6)H(4)SeTpc)。ArSeR中的Se-C(R)键位于pl中的Ar平面上,并且垂直于pd中的平面。相对于Y = NMe(2),OMe和Me(-22至-6 ppm),观察到较大的上场偏移;对于Y = COOEt,CN和NO(2)(19-37 ppm),观察到较大的下场偏移。 Y = H,卤素具有小的向上场偏移和中等向下场偏移(Y = F为-1 ppm,Y = Cl和Br为4 ppm)。这必须是1(pl)中p(Se)-pi(C(6)H(4))-p(Y)共轭的结果。尽管1(pl)中的delta(Se)的特性与9-(芳基
硒基)
蒽(2(pl))的特性非常相似,但它与1-(芳基
硒基)
蒽醌(3(pd))的特性却非常不同。 )。溶液中的del(