Infrared spectroscopy absorption table. From OChemOnline. Jump to: navigation, search. The following table lists infrared spectroscopy absorptions by frequency regions. The complexity of this spectrum is typical of most infrared spectra, and illustrates their use in identifying substances. The gap in the spectrum between 700 & 800 cm-1 is due to solvent (CCl4) absorption. The following table provides a collection of such data for the most common functional groups. Following the color scheme of the chart, stretching absorptions are listed in the blue-shaded section and bending absorptions in the green shaded part. Transitions between vibrational energy states may be induced by absorption of infrared radiation, having photons of the appropriate energy. Other X-H stretching frequencies are shown in the table to the left, the trends observed being due chiefly to differences in the force constants.
Infrared Absorption Frequencies. Numbers separated by dashes are ranges; when two numbers are separated by a comma, both absorptions are expected. Individual numbers not components of a range should be considered 5 cm-1. The chemical shift of an alkane CH depends on the other groups bonded to carbon. The following table lists typical chemical shifts for methyl hydrogens, that is, for XCH3 groups. (The table has been adapted from a reserve text: Pretsch et al. Functional Group, Molecular Motion, Wavenumber (cm-1). alkanes. CnH2n+2. C-H stretch, 2950-2800. CH2 bend, 1465. CH3 bend, 1375. CH2 bend (4 or more), 720. alkenes. CnH2n. CH stretch, 3100-3010.
Answer to First image is IR absorption table, second is the question.