2-置換フルオレンの炭素-13核磁気共鳴スペクトルにおける置換基効果

The carbon-13 NMR chemical shifts for thirteen 2-substituted fluorenes have been measured in chloroform-d at 100MHz. The substituent induced chemical shifts (SCS) for C_<11>, showed an inversed trend where as SCS for C_7 exhibited normal trend in the sense of the substituent electronic effect. These phenomena are as good as those observed for the SCS of the corresponding carbons of the 4-substituted biphenyls. The π electrons of the remote benzene ring were polarized by the charge of the substituted phenyl moiety.