Abstract Many Chinese organic chemistry textbooks classify conjugation into π-π conjugation,p-π conjugation,and hyperconjugation.Based on the IUPAC definitions of these concepts,this paper claims that hyperconjugation is not a type of conjugation,and should not be listed in parallel to π-π and p-π conjugations.We also suggest that the related Chinese textbooks might pay attention to the questions discussed herein,clarify the relations between hyperconjugation and conjugation,and pinpoint their similarities and differences.
