一、引言1931年Pauling提出原子轨道杂化理论时,为了说明乙烯的cc双键的本性,还提出弯键的概念。他认为乙烯的碳原子轨道是sp~3杂化的,两个碳原子各以两个sp~3杂化轨道相互重叠组成两支弯键。另一方面,Coulson则认为乙烯的碳原子轨道是sp~2杂化的,两个碳原子各以一个杂化轨道重叠组成一支σ键;各以一个未杂化的P轨 I. INTRODUCTION Pauling proposed the atomic orbital hybridization theory in 1931, in order to illustrate the nature of the ethylene double bond cc, but also put forward the concept of curved key. He believes that carbon orbitals of ethylene are sp ~ 3 hybridized, two carbon atoms each with two sp ~ 3 hybrid orbital overlap to form two curved bonds. Coulson, on the other hand, believes that the carbon orbital of ethylene is sp ~ 2 hybridized with two carbon atoms each forming a σ bond by a hybrid orbital overlap; each with an unhybridized P rail