关键词: ¹³C化学位移, 开链烷烃, 逐步回归, 电子效应, 空间效应

Abstract: The ¹³C chemical shifts in acyclic aliphatic hydrocarbon molecules were correlated to the electron populations at the neibouring atoms and to the local steric energies of the considered ¹³C atoms.
Data of 72 ¹³C atoms included in 14 typical molecules have been treated by the step regression method. The final obtained regression equation and the values of all relevant statistic quantities show an evident linear relation between the ¹³C chemical shift and the other mentioned factors. The ovarall root-mean-square deviation of the predicted ¹³C chemical shift values is 0.835ppm and the maximun deviation is 2.232ppm.

Key words: ¹³C Chemical shifts, Acyclic aliphatic hydrocarbon, Step regression, Electronic effect, Steric effect