Infrared spectroscopy bending motions

In the infrared spectmm of free carbon dioxide, the asymmetric stretching frequency is observed at 2349 cm-1 (gas) and 2342 cm-1 (solid). The infrared absorption belonging to the bending motion of the molecule is found at 667 cm-1 (gas). Symmetric stretching of free CO2 can be detected only by Raman spectroscopy... 

Infrared spectroscopy identifies the kinds of functional groups in a compound. Bonds vibrate with stretching and bending motions. Each stretching and bending vibration occurs with a characteristic frequency. It takes more energy to stretch a bond than to bend it. When a compound is bom-... 

Infrared spectroscopy (IRS) is the study or analysis of how the bonds between atoms of a molecule absorb energy and vibrate or bend (deform) much like springs. The energy necessary to cause motions in these bonds is quite specific and provides the forensic scientist with information about how atoms and combinations of atoms are associated in a molecule. 

Infrared and Raman spectra have long been used to probe the structure and strength of interactions in liquid water. The vibrational density of states, components of which are probed by both these forms of spectroscopy, can be divided into three components. At the lowest frequencies, usually below about 100 cm , the most important vibrations are associated with translational motions in which the molecular centers of mass are moving with respect to each other. Between 100 cm and 1000 cm" the vibrational density of states is dominated by intermolec-ular rotational and librational motions. Near 1600 cm there is a fairly broad band arising from intramolecular HOH bending modes. Then, between 3100 cm" and 3400 cm" the intramolecular vibrations become important. There are quite impor-... 

In the context of the heat capacity, the term "vibrational motions" should be interpreted in the most general manner possible, to encompass all possible modes of motion of atoms or groups of atoms in a macromolecule. Such motions include bond stretching, bond bending and "rocking" motions, torsional oscillations, the "flipping" of a structural unit from one equilibrium position to another, and large-scale cooperative motions. These internal motions of atoms in a material are most directly studied by vibrational (infrared and Raman) spectroscopy [23]. 

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