Advanced search
Start date
Betweenand
Conteúdos relacionados
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Conformational analysis of 2-halocyclopentanones by NMR and IR spectroscopies and theoretical calculations

Full text
Author(s):
Martins, Carina R. [1] ; Ducati, Lucas C. [1] ; Tormena, Claudio F. [1] ; Rittner, Roberto [1]
Total Authors: 4
Affiliation:
[1] State Univ Campinus, Inst Chem, Phys Organ Chem Lab, BR-13084971 Campinas, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY; v. 72, n. 5, p. 1089-1096, JUN 2009.
Web of Science Citations: 5
Abstract

The conformational isomerism of 2-chlorocyclopentanone and 2-bromocyclopentanone has been determined through the solvent dependence of the (1)H NMR (3)J(HH) coupling constants, theoretical calculations and infrared data, using the solvation theory for the treatment of NMR data. In 2-chlorocyclopentanone, the energy difference (E(psi-r) - E(psi-a)), in the isolated molecule at B3LYP level of theory, between the pseudo-equatorial (psi-e) and pseudo-axial (psi-a) conformers is 0.42 kcal mol(-1), which decreases ill CCl(4) and in acetonitrile Solutions. in good agreement with infrared data (vc=o), despite the uncertainties of the latter method. The conformational equilibrium for 2-bromocyclopentanone is also between the psi-e and psi-a conformations, with an energy difference (E(psi-p) - E(psi-a)), in the isolated molecule at B3LYP level of theory, is 0.85 kcal mol(-1) which decreases in CCl(4) and in acetonitrile Solutions, also in good agreement with infrared data. (C) 2009 Elsevier B,V. All rights reserved. (AU)

FAPESP's process: 05/59649-0 - Conformational equilibria studies by nuclear magnetic resonance spectroscopy, infrared spectroscopy and theoretical calculations
Grantee:Roberto Rittner Neto
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 06/02783-9 - Desenvolvimento de funções de base para cálculo teórico de acoplamentos J(P,P), J(P,C) e J(P,H)
Grantee:Lucas Colucci Ducati
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 06/03980-2 - Interacoes de orbitais e seus efeitos nas constantes de acoplamento escalar em rmn: estudo experimental e teorico.
Grantee:Claudio Francisco Tormena
Support Opportunities: Regular Research Grants