ORGANIC CHEMISTRY Chapter 4 Energy changes that arise from rotation about the c2-c3 bond of butane CH CH CH3 H 1 H 5 个HH CH3 CH CH CH H H CB◇ H 2 6 CH3 4 3.7 kJ/mol 15.9 kJ/mol 18.8 kJ/mol 120 240 300 360 旋转角度 Department of Chemistry, Xiamen UniversityORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 4 Energy changes that arise from rotation about the C2—C3 bond of butane 60 120 180 240 300 360 E 3.7 kJ/mol 15.9 kJ/mol 18.8 kJ/mol CH3 H H H H CH3 CH3 H H HH CH3 H H H CH3H CH3 H CH3 HH H CH3 H H CH3 H H CH3 CH3 H H H H CH3 1 2 3 4 5 6 CH3 H H HH CH3 1 旋转角度