Spin Trapping by Use of Nitroso-Compounds. VII. β-Fluorine Splitting Constants in Nitroxides
スポンサーリンク
概要
- 論文の詳細を見る
Hyperfine splitting constants of β-fluorine atoms in aryl perfluoroalkyl nitroxides, ArN(R<SUB>f</SUB>)O·, where Ar= 2,4,6-tri-<I>t</I>-butylphenyl, phenyl, pentafluorophenyl, and 2,3,5,6-tetramethylphenyl and R<SUB>f</SUB>=trifluoromethyl, pentafluoroethyl, and heptafluoroisopropyl were explored. The temperature dependence of hyperfine splitting constants was studied in the cases of 2,4,6-tri-<I>t</I>-butylphenyl and pentafluorophenyl nitroxides. In the former nitroxides the conformation of β-fluorine atoms are rigid and dihedral angles between the C<SUB>β</SUB>–F bonds and p<I><SUB>z</SUB></I> orbitals are 30 and 0° when perfluoroalkyl groups are ethyl and isopropyl, respectively. The conformational dependence of β-fluorine splitting constants are discussed, and it is concluded that the cos<SUP>2</SUP>θ law, <I>a</I><SUB>β</SUB><SUP>F</SUP>=(<I>B</I><SUB>0</SUB>+<I>B</I>cos<SUP>2</SUP>θ)ρ<SUP>π</SUP>, is also applicable to β-fluorine splitting constants in a series of nitroxides. The values of <I>B</I><SUB>0</SUB> and <I>B</I> seem significantly dependent on the compound.
著者
-
Konaka Ryusei
Shionogi Research Laboratory, Shionogi & Co., Ltd.
-
Terabe Shigeru
Shionogi Research Laboratory, Shionogi & Co., Ltd.