THE SYMMETRY AND SPECTRAL PROPERTIES OF HELICAL POLYNUCLEOTIDES

Journal Article · Sun Sep 01 04:00:00 EDT 1963 · Radiation Res.

DOI:https://doi.org/10.2307/3571339· OSTI ID:4694264

Rhodes, W

The results of applying the theory of space groups to a model double- stranded helix were used to describe the electronic states (exciton states) of helical polynucleotides. The role of symmetry in determining the nature of the pi pi /sup */ and n pi /sup */ exciton bands of the helix is considered. Selection rules are given for electric-dipole transition between the ground state and exciton bands and for the mixing of zeroth-order states which results from interactions within the helix. Perturbation theory is used to determine quantitatively the effect of pi pi /sup */ mixing on the intensity of an n yields pi /sup */ transition which presumably is present on the lowenergy side of the 2600-A pi yields pi /sup */ absorption band. Since pi pi /sup */- n pi /sup */ mixing to first order is zero, it is necessary to use third-order perturbation theory. Results show that on formation of the helix such mixing may be sufficient to account for the observed increase in intensity in the region 2800 to 2900 A; however, the stolen intensity should appear as a perpendicularly polarized component. Other kinds of interaction which may account for the observed intensity increase are discussed. (auth)

• Research Organization: Florida State Univ., Tallahassee
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-040846
• OSTI ID: 4694264
• Journal Information: Radiation Res., Journal Name: Radiation Res. Vol. Vol: 20
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
ATOMIC MODELS
CHEMISTRY
CONFIGURATION
CRYSTALS
DIPOLES
ENERGY LEVELS
EXCITATION
EXCITONS
INTERACTIONS
PERTURBATION THEORY
QUANTUM MECHANICS
SPECTRA