Artículos de revistas
Intra- and intermolecular hydrogen bonds in alkyl and silyl ethers: Experimental and theoretical analysis
Registro en:
Journal Of Physical Chemistry A. Amer Chemical Soc, v. 112, n. 2, n. 232, n. 237, 2008.
1089-5639
WOS:000252287100011
10.1021/jp709601w
Autor
Dias, LC
Ferreira, MAB
Tormena, CF
Institución
Resumen
We have investigated the electronic impact of the R protecting group (TBS or PMB) in the conformational equilibrium of a-methyl substituted alcohols 1 (R = TBS) and 2 (R = PMB). The conformational analysis and H-1 NMR experiments for alcohols 1 and 2 reflect the tendency for the existence of hydrogen-bonded conformations. The intrinsic low basicity of silyl ethers does not affect the capacity of the oxygen attached to the silicon atom in forming, intramolecular hydrogen bonds. We showed that the extents of the hydrogen bonds in silyl and alkyl ethers are determined by several properties, Such as orbital interactions, lone pair hybridizations, and lone pair energies, and not just by the electronic occupancy of the donor atom. The populational analysis of NBO allowed understanding the intra- and intermolecular hydrogen bonds between the OH group and oxygen bonded to silicon as well as to alkyl ethers, concluding that there are distinct lone pair contributions. 112 2 232 237