%0 Journal Article
%T Molecular Structure of Heterocycles: 6. Solvent Effects on the 17O Nmr Chemical Shifts of 5-Trichloromethylisoxazoles
%A Martins
%A Marcos A. P.
%A Freitag
%A Rog¨¦rio A.
%A Zimmermanna
%A Nilo E. K.
%A Sinhorin
%A Adilson P.
%A C¨²nico
%A Wilson
%A Bastos
%A Giovani P.
%A Zanatta
%A Nilo
%A Bonacorso
%A Helio G.
%J Journal of the Brazilian Chemical Society
%D 2001
%I Sociedade Brasileira de Qu¨ªmica, SBQ
%R 10.1590/S0103-50532001000600019
%X a multilinear-regression analysis using the kamlet-abboud-taft (kat) solvatochromic parameters in order to elucidate and quantify the solvent effects on the 17o chemical shifts of three 5-trichloromethylisoxazoles [(1a) non-, (1b) 3-methyl- and (1c) 4-methyl-substituted] is reported. the chemical shifts of ring oxygen atom, o1, of compounds 1a-c show dependencies (in ppm) on the solvent polarity-polarizability of -4.8p*, -3.2p*, -8.9p*, on the solvent hydrogen-bond-donor (hbd) acidities 0.9a, -0.2a, -2.7a and the solvent hydrogen-bond-acceptor (hba) basicities -0.4b, 1.9b, 0.9b, respectively. the data of net charges of o1 and dipole moment, obtained from mo calculations (am1), are compared with the solvent effect parameters obtained for compounds 1a-c.
%K 17o nmr
%K solvent effects
%K isoxazoles
%K mo calculations.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0103-50532001000600019&lng=en&nrm=iso&tlng=en