Ab initio study of the vibrational spectra of N sub 9 -H and N sub 7 -H adenine and 9-methyladenine

Journal Article · Wed Jun 20 00:00:00 EDT 1990 · Journal of the American Chemical Society; (USA)

DOI:https://doi.org/10.1021/ja00169a045· OSTI ID:6644320

Wiorkiewicz-Kuczera, J; Karplus, M ^[1]

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1. Harvard Univ., Cambridge, MA (USA)

The structures and vibrational spectra of adenine in two tautomeric forms (N{sub 9}-H and N{sub 7}-H) and 9-methyladenine have been calculated at the Hartree-Fock level with a 4-21G basis set and are in good agreement with experimental structural data. The ab initio normal modes have been used to interpret experimental vibrational data for adenine and 9-methyladenine isolated in an argon matrix, in the crystalline solid and in solution. Experimental band assignments of the spectra in the low-temperature matrix and in the polycrystalline state have been analyzed and several reassignments have been proposed. Overall the agreement between the experimental argon matrix and calculated results is very good; for the scaled ab initio frequencies the deviation from experiment is 3% for the entire frequency range. These results have proved to be helpful in analyzing experimental band assignments in spectra of deuterated adenine derivatives and in verifying the assignments for the undeuterated molecules.

• OSTI ID: 6644320
• Journal Information: Journal of the American Chemical Society; (USA), Journal Name: Journal of the American Chemical Society; (USA) Vol. 112:13; ISSN 0002-7863; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ADENINES
AMINES
ANTIMETABOLITES
AROMATICS
AZAARENES
BIOCHEMISTRY
CALCULATION METHODS
CHEMISTRY
DRUGS
ENERGY LEVELS
EXCITED STATES
HARTREE-FOCK METHOD
HETEROCYCLIC COMPOUNDS
MATHEMATICAL MODELS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PURINES
VIBRATIONAL STATES