dc.creator | Freitas, MP | |
dc.creator | Tormena, CF | |
dc.creator | Rittner, R | |
dc.creator | Abraham, RJ | |
dc.date | 2003 | |
dc.date | JAN | |
dc.date | 2014-11-17T13:16:40Z | |
dc.date | 2015-11-26T17:38:16Z | |
dc.date | 2014-11-17T13:16:40Z | |
dc.date | 2015-11-26T17:38:16Z | |
dc.date.accessioned | 2018-03-29T00:19:53Z | |
dc.date.available | 2018-03-29T00:19:53Z | |
dc.identifier | Journal Of Physical Organic Chemistry. John Wiley & Sons Ltd, v. 16, n. 1, n. 27, n. 33, 2003. | |
dc.identifier | 0894-3230 | |
dc.identifier | WOS:000180407000005 | |
dc.identifier | 10.1002/poc.565 | |
dc.identifier | http://www.repositorio.unicamp.br/jspui/handle/REPOSIP/56508 | |
dc.identifier | http://www.repositorio.unicamp.br/handle/REPOSIP/56508 | |
dc.identifier | http://repositorio.unicamp.br/jspui/handle/REPOSIP/56508 | |
dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/1286158 | |
dc.description | The conformational equilibria of trans-1-methoxy-2-chloro- (1), trans-1-methoxy-2-bromo- (2) and trans-1-methoxy-2-iodocyclohexane (3), and their corresponding alcohols (4-6), were studied through a combined method of NMR, theoretical calculations and solvation theory. They can be described in terms of the axial-axial and equatorial-equatorial conformations, taking into account the main rotamers of each of these conformations. From the NMR experiments at 183 K in (CDCl2)-Cl-2-CS2, it was possible to observe proton H-2 in the ax-ax and eq-eq conformers separately for 1 and 2, but not for 3, which gave directly their populations and conformer energies. In the alcohols the proportion of the ax-ax. conformer was too low to be detected by NMR under these conditions. Those HH couplings together with the values at room temperature, in a variety of solvents allowed the determination of the solvent dependence of the conformer energies and hence the vapor state energy difference. The DeltaE (E-ax-E-eq) values in the vapor state for 1, 2 and 3 are -0.05, 0.20 and 0.55 kcal mol(-1), respectively, increasing to 1.10, 1.22 and 1.41 kcal mol(-1) in CD3CN solution (I kcal = 4.184 kJ). For 4-6 the eq-eq conformation is always much more stable in both non-polar and polar solvents, with energy differences ranging from 1.78, 1.94 and 1.86 kcal mol(-1) (in CCl4) to 1.27, 1.49 and 1.54 kcal mol(-1) (in DMSO), respectively. Comparison of the hydroxy and methoxy compounds gives the intramolecular hydrogen bonding energy for the alcohols as 1.40, 1.36 and 1.00 kcal mol(-1) (in CCl4) for 4, 5 and 6, respectively. Copyright (C) 2002 John Wiley Sons, Ltd. | |
dc.description | 16 | |
dc.description | 1 | |
dc.description | 27 | |
dc.description | 33 | |
dc.language | en | |
dc.publisher | John Wiley & Sons Ltd | |
dc.publisher | W Sussex | |
dc.publisher | Inglaterra | |
dc.relation | Journal Of Physical Organic Chemistry | |
dc.relation | J. Phys. Org. Chem. | |
dc.rights | fechado | |
dc.rights | http://olabout.wiley.com/WileyCDA/Section/id-406071.html | |
dc.source | Web of Science | |
dc.subject | trans-1,2-disubstituted cyclohexanes | |
dc.subject | conformational analysis | |
dc.subject | NMR | |
dc.subject | density functional theory | |
dc.subject | Ab-initio | |
dc.subject | Isomerism | |
dc.subject | Cyclohexanes | |
dc.subject | Oh | |
dc.title | Conformational analysis of trans-2-halocyclohexanols and their methyl ethers: a H-1 NMR, theoretical and solvation approach | |
dc.type | Artículos de revistas | |