Salesians of Don Bosco Ng Siu Mui Secondary

Salesians of Don Bosco Ng Siu Mui Secondary School 天主教慈幼會伍少梅中學 IR Spectroscopy 紅外色譜學 Wu L. M. http: //walk. to/wu

HKAL課程中對紅外色譜學的要求 Syllabus: Instrumentation Analysis An awareness that spectroscopic methods such as infra-red spectroscopy and nuclear magnetic resonance (NMR) can provide information about the structure of a molecule. n

nuclear magnetic resonance (NMR) n NMR spectroscopy typically gives the hydrocarbon fragments

infra-red spectroscopy n the most useful information obtained from an IR spectrum is what functional groups are present within the molecule

Topic: Use of infra-red (IR) spectrum in the identification of functional groups IR spectrum and its use in the identification of the following groups: C-H O-H N-H C=C C≡C C=O and C ≡ N (Instrumentation is not required) n

Suggested Experiments / Activities Inspection of IR spectrum of organic compounds. n

紅外線化學儀器 IR Spectroscopy Instrument 伍少梅紅外線化學分析網頁 http: //hk. geocities. com/tempalbum/

7 IR Characteristic peaks n n n 7 vibrational movement (covalent bond )共價鍵 7個主要官能基 分子的指紋(peak)

官能基 譜峰位置 / cm-1 Alkane, C–H 2850– 2960 Alkene, =C–H 3020– 3100 Alkene, C=C 1650– 1670 Alkyne, ≡C–H 3300 Alkyne, –C≡C– 2100– 2260 Alcohol, O–H 3400– 3640 Alcohol, C–O 1050– 1150 Carboxylic, O–H 2250 -3100 Amine, N–H 3310– 3500 Amine, C–N 1030, 1230 Carbonyl, C=O 1670– 1780 Nitrile, C≡N 2210– 2260

Characteristic Infra-red Absorption Wave number Ranges (Stretching modes) HKAL

IR spectrum

IR Real Spectrum

IR Spectroscopy Experiment 實驗過程短片 香港科技大學

Learning time………. Are you read to examine some IR Spectrum?

Alkane C-H： 2840 -3095

Alkene =C-H： 3020 -3100 C=C： 1610 -1680

Alkynes C ≡ C： 2100 -2260 C-H： 3300 ≡

Alcohol O-H： 3400 -3640

Alkanoic acid O-H： 2250 -3100

Amine N-H： 3310 -3500

Ketone C=O： 1670 -1780

Aldehyde C=O： 1670 -1780

Nitrile CN C≡N： 2200 -2260

Test time………. Are you read to identify one unknown IR Spectrum?

Quick Test Ester C=O： 1670 -1780 C-H： 2840 -3095

自學網頁 n 胡老師網頁 及 其他參考網頁 n n n http: //walk. to/wu http: //hk. geocities. com/tempalbum/ http: //orgchem. colorado. edu/hndbksupport/irtutor/tutorial. html http: //www. hkedcity. net/resources/ires_browse. phtml? res_c at_id=2870 http: //www. chem. ucalgary. ca/courses/351/Carey/Ch 13/ch 13 -ir 1. html http: //www. cofc. edu/~chem/organic/Slides/IR 2 c/sld 019. htm 拜拜！