ORGANIC CHEMISTRY Chapter 4 Potential energy diagram for rotation about the cc bond in ethane 重叠式构象 E 交叉式构象 H H H HCHH HH H H H H H H H 12. 1 kJ/mol 60° 120° 180 240旋转角度 Department of Chemistry, Xiamen UniversityORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 4 Potential energy diagram for rotation about the C—C bond in ethane 60 120 180 240 E H H H H H H H H H HH H 重叠式构象 交叉式构象 H H H H H H H H H HH H 12.1 kJ / mol 旋转角度