ISSN:
1089-7690
Quelle:
AIP Digital Archive
Thema:
Physik
,
Chemie und Pharmazie
Notizen:
We have observed a noncoincidence splitting of 1–2 cm−1 for the 1505 cm−1 adenine base vibration in poly(rA), poly(dA), 5rAMP, and 5dAMP. In double stranded polynucleotides, the noncoincidence splitting is smaller than 0.3 cm−1. Noncoincidence splitting is usually associated with a transition dipole–transition dipole coupling between identical vibrational modes on different molecules of the same species, but any angular dependent intermolecular coupling mechanism may cause this effect. It is argued that resonant vibrational coupling of 1505 cm−1 vibrations on different adenine bases cannot be the source of the noncoincidence splitting. As the 1505 cm−1 base vibration does not have a large infrared absorption, it cannot be caused by transition dipole–transition dipole coupling. We propose that a coupling via hydrogen bonding of the 1505 cm−1 adenine base vibration to water vibrations yields the angular dependent intermolecular coupling potential. © 1997 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.473966
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