We developed a new model to study the molecular dynamics of the acetanilide (ACN) crystal by computer simulation. Low-frequency oscillations of the molecules as a whole were considered with high-frequency vibrations of the amidic degrees of freedom involved in hydrogen bonding. The low-temperature power spectrum has two peaks, shifted by 15 cm^-1, in the region of the amide I band: one of them corresponds to the so-called anomalous amide I band in the IR and Raman spectra of ACN. We found that this peak is due to the coupling of the low-frequency motion in the chain of molecules with the motion of the hydrogen-bonded protons, at variance with current suggestions.
On the unconventional amide I band in acetanilide / Tenenbaum, Alexander; Alessandro, Campa; Giansanti, Andrea. - In: PHYSICS LETTERS A. - ISSN 0375-9601. - STAMPA. - 121:(1987), pp. 126-130. [10.1016/0375-9601(87)90405-1]
On the unconventional amide I band in acetanilide
TENENBAUM, Alexander;GIANSANTI, Andrea
1987
Abstract
We developed a new model to study the molecular dynamics of the acetanilide (ACN) crystal by computer simulation. Low-frequency oscillations of the molecules as a whole were considered with high-frequency vibrations of the amidic degrees of freedom involved in hydrogen bonding. The low-temperature power spectrum has two peaks, shifted by 15 cm^-1, in the region of the amide I band: one of them corresponds to the so-called anomalous amide I band in the IR and Raman spectra of ACN. We found that this peak is due to the coupling of the low-frequency motion in the chain of molecules with the motion of the hydrogen-bonded protons, at variance with current suggestions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
