2.等瓣（等叶片）相似 R.Hoffmann,(Nobel Lecture,1982) "Building Bridges between Inorganic and Organic Chemistry" Angew.Chemie.Vol 21,10(1982)711-724 有机分子片： CH3 CH2 CH 无机分子片： M(CO)s M(CO)4 M(CO)3 有机分子片: CH3 CH2 CH 无机分子片: M(CO)5 M(CO)4 M(CO)3 2. 等瓣(等叶片)相似 R. Hoffmann, (Nobel Lecture, 1982) “Building Bridges between Inorganic and Organic Chemistry” Angew. Chemie. Vol 21, 10(1982)711-724