Spectroscopy uses radiation (in this case, infrared light) to excite a molecule to learn about its properties. Photons at a precise wavelength will be absorbed by certain functional groups, causing a vibration in the molecule through stretching, compressing, or bending a bond or group of bonds. These motions must be polarthey must change the dipole of the moleculeto be visible in IR. Most spectra have a fingerprint region at low energy with many overlapping signals that usually requires a computer to process. This lecture includes the IR spectrums of an alkane (pentane), an alkeen (1-Pentene), an alkyne (1-pentyne), an aromatic compound (methylbenzene), substituted aromatic compounds (1,2-, 1,3-, and 1,4-dimethylbenzene), an alcohol (1-pentanol), amines (1-butanamine, diethylamine, and triethylamine), a ketone (2-butanone), an aldehyde (pentanal), an ester (butyl propanoate), and a carboxylic acid (butanoic acid). It also provides a correlation chart for further IR problems with several standard IR peaks as well as several example problems.
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.