ORGANIC CHEMISTRY Chapter 2 wavelength〔 leans) 25 1213茸4116μ - N-H CN,O C一Cc-0,C—N e●●e 5·画3]恐5卫召恐蜇1奶111 frequency v) Department of Chemistry, Xiamen UniversityORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 2