CHEM 343 Study Guide - Quiz Guide: Infrared Spectroscopy, Wavenumber, Chemical Shift
Document Summary
Measures the attenuation of a beam of light (visible or ultraviolet) after it passes through a sample or after reflection from a sample surface. Measures the vibration of the atoms, and based on that, can determine the functional group. Nmr spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of its molecules. Nmr spectroscopy with respect to carbon and allows the identification of carbon atoms in an organic molecule. Vertical: no variable, just size of peak and splittings. Ir spectroscopy is based on the vibrations of molecules, including bending and stretching. In order for ir light to be absorbed, the vibration of the molecule must result in a change in a bond dipole moment: symmetrical molecules do not have a dipole moment and therefore do not absorb ir light. The size of each peak represents the number of equivalent protons in a group.
