Molecular structure, conformation, and large amplitude motion of barbituric acid as studied by gas-phase electron diffraction and quantum chemical calculations

Autor:	Ilya I. Marochkin, Olga V. Dorofeeva, Heinz Oberhammer, Igor F. Shishkov, Nikolai M. Karasev
Rok vydání:	2011
Předmět:	Barbituric acid Condensed Matter Physics Ring (chemistry) Molecular physics Bond length chemistry.chemical_compound Crystallography Amplitude Planar chemistry Electron diffraction Molecule Physics::Chemical Physics Physical and Theoretical Chemistry Envelope (waves)
Zdroj:	Structural Chemistry. 22:419-425
ISSN:	1572-9001 1040-0400
Popis:	B3LYP and MP2(Full) calculations with large basis sets predict the planar equilibrium structure of barbituric acid and reveal large amplitude ring puckering motion which is associated with envelope conformation. The potential function for this motion has only one minimum. This function was used in the analysis of the gas-phase electron diffraction (GED) data in terms of a dynamic model. The least-squares refinements applying dynamic model agree well with the GED data, whereas the agreement is not satisfactory for a planar static model. There is a good agreement between the experimental structural parameters and those from B3LYP/cc-pVTZ calculation. The MP2(Full)/cc-pVTZ values of C–C and C–N bond lengths are 0.02–0.03 A less than the experimental ones. The structure of the molecule is compared with the structures of several related molecules.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::8e990cc65f4c67946eec43f8f9968b16 https://doi.org/10.1007/s11224-011-9743-x Zobrazit plný text záznamu Full text from SpringerLink