Hydrogen-out-of-plane

In 2-substituted thiophenes these bands are found in the ranges 1537-1509, 1444-1402, 1365-1339 and 1258-1220 cm-1, along with hydrogen in-plane absorption at 1086-1077 and 1053-1031 cm "1, and hydrogen out-of-plane absorption at 938-905 and 863-841 cm-1 as well as a ring breathing mode at 839-790 cm-1 (59JCS3500). 

It has also been reported that an aromatic carbon-hydrogen out of plane deformation band at 759 cm"1 was sensitive to sequence distribution in styrene-maleic anhydride copolymers (2). A shoulder was noted at this frequency in the infrared spectra of the block copolymer, but it was not possible to demonstrate differences in the spectra of the alternating and block copolymers with the instrumentation available. 

FIGURE 6.4 (a) Energy variation (in kcal/mol) and hcc for carbon and hydrogen atoms as a function of the hydrogen out-of-plane angle in methyl radical. PBEO/EPR-II computations, (b) Decomposition of the total hcc in its direct and spin polarization contribution. 

Ohkita YJ, Sasaki J, Maeda A, et al. Changes in structure of the chromophore in the photochemical process of bovine rhodopsin as revealed by FTIR spectroscopy for hydrogen out-of-plane vibrations. Biophys Chem 1995 56 71-78. 

Figure 10. Spectra showing the aromatic hydrogen out-of-plane bending vibrations in different coals and semicokes—25 times accumulation. Key top row, Pittsburgh No, 8 middle row, Lower Kittanning and bottom row, Illinois No. 6.

Table 39. Carbon-Hydrogen Out-of-plane Bending Bands of Benzenium Ions in IR Spectra of A + HCl GaClj Systems... 

We then investigated the excited-state dynamics by analyzing deuterium substitution effects for hydrogen atoms bonded to Cll and C12 of the retinal chromophore. The substitution effects do not appear significantly in the excited-state dynamics until about 60 fs, but they appear after 60 fs. The mode of isomerization at C11-C12 double bond would couple with the mode of hydrogen-out-of-plane and, therefore, isomerization would start at about 60 fs after photon absorption of rhodopsin. 

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