Accession Number:

ADA172347

Title:

On the Pyrazine and Pyrazine-Pyrimidine Dimers.

Descriptive Note:

Technical rept.,

Corporate Author:

COLORADO STATE UNIV FORT COLLINS DEPT OF CHEMISTRY

Personal Author(s):

• Wanna,J.
• Bernstein,E. R.

Report Date:

1986-06-01

Pagination or Media Count:

33.0

Abstract:

Spectra of the pyrazine-d sub 4, pyrazine-h sub 4-pyrazine-d sub 4-pyrimidine dimer are obtained and analyzed with the help of Lennard-Jones-hydrogen-bonding LJ-HB potential energy calculations. The pyrazine isotopic hetero- and homo-dimers possess nearly identical spectra with the exception that the perpendicular dimer features are displaced to the red by approx. 11 cm. Exchange or exciton interactions in this system are vanishingly small less than 1cm. The geometrics suggested by the isotopically substituted pyrazine dimer spectra are the same as those found for the pyrazine-h sub 4 homo-dimer a parallel planar hydrogen bonded and a perpendicular dimer. The pyrazine-h sub 4 and pyrazine-h sub 4-pyrimidine dimer spectra are quite complicated. These spectra can be assigned as rising from one parallel stacked head-to-tail displaced dimer, one parallel planar dimer, and 3 perpendicular dimers based on comparisons with spectra of the pyrazine and pyrimidine dimers.

Descriptors:

• *MASS SPECTROSCOPY
• *DIMERS
• *PYRIMIDINES
• HYDROGEN BONDS
• COMPUTATIONS
• MOLECULAR VIBRATION
• INTERACTIONS
• HYDROGEN
• VERTICAL ORIENTATION
• PLANAR STRUCTURES
• ISOTOPES
• GEOMETRY
• MOLECULE MOLECULE INTERACTIONS
• PARALLEL ORIENTATION
• POTENTIAL ENERGY
• EXCITONS

Subject Categories:

• Polymer Chemistry
• Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE