Vibration scissor mode

Next are the vibrations in which the bond angle varies periodically but the bond length remains constant. This is called a scissor-mode vibration, because it looks like the action of a pair of scissors, as depicted in Figure 9.22(b). 

Figure 9.22 Simple vibration modes for carbon dioxide, 0=C=0 (a) a symmetric stretching mode and (b) a scissor mode vibration...

Fig. 6.15 The increase in the Si-O-Si vibrational modes (980-1200 cm"1) upon storage of a high porosity (75%) micro PS layer formed on a p-type substrate (0.2 Q cm) in ambient air. The Si—H2 scissors mode (905 cm"1) shows little time dependence. After [Th7],...

The vibrational spectrum of LiC2H4 presents some striking similarities to that of ethylene bonded to other metals . The C—C stretching and in-phase CH2 scissoring modes were found to be very strongly IR-activated. The other symmetrical vibrations, CH2 wagging and Li—C stretching motions, were detected at about 700 and 300 cm 48,50 ... 

Fundamental vibrations involve no change in the center of gravity of the molecule. The three fundamental vibrations of the nonlinear, triatomic water molecule are depicted in the top portion of Figure 2.1. Note the very close spacing of the interacting or coupled asymmetric and symmetric stretching compared with the far-removed scissoring mode. 

Fig. 2.3. Combination and difference band progressions involving the ring puckering vibration and a CH2 scissoring mode in the mid-infrared spectrum of cyclobutane.

Fig. 1 Confirmation of Si-C grafting reaction by HF treatment. Fourier transform infrared (FTIR) speetmm of a porous Si sample modified with a dodeeyl functionality by thermal hydrosilylation of 1-dodecene (Eq. 19) and then treated with an aqueous HF/ethanol solution. The hydrosilylation reaction replaces some of the Si-H bonds at the surface with Si-C bonds, which are not attacked by HF. If the Si-C grafting reaction is successful, vibrational bands associated with the organic group (primarily the C-H stretching and CH2 wag, or scissors, modes from the grafted species) should be observed even after the sample has been thoroughly rinsed with the HF solution...

FIG. 9 Diagram illustrating the three vibrational modes (31V— 6) of water in the gas phase. (A) The first mode is called bending, in which the water molecule moves in a scissors-like manner. (B) The second is the symmetric stretch, where the hydrogen atoms move away from (or toward) the central oxygen atom simultaneously—i.e., in-phase motion. (C) The third is the asymmetric stretch, in which one hydrogen atom approaches the central oxygen atom, while the other moves away—i.e., out-of-phase motion. 

Fig. 5.3. The three vibrational modes of H2S. (A) Represents the scissoring motion, (B) is the symmetrical stretch and (C) is the asymmetrical stretch.

Figure 4.3 Vibrational modes of a nonlinear triatomic molecule such as H20. Arrows indicate motion in the plane of the paper, + is towards and - away from the observer, (a) symmetric stretching, (b) asymmetric stretching, (c) out-of-plane wagging, (d) out-of-plane twisting, (e) in-plane scissoring, (f) in-plane rocking.

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