309249-49-8Relevant articles and documents
Heterocycle-substituted stable thioaminyl radicals: Isolation, ESR spectra, and magnetic properties
Miura,Tomimura,Teki
, p. 7889 - 7895 (2000)
N-[(2-Benzothiazolyl)thio]- (1), N-[(2-benzoxazolyl)thio]- (2), and N-(2-pyrimidylthio)-2,4,6-trisubstituted-phenylaminyls (3) were generated by oxidation of the corresponding amines. Although 2 and were not sufficiently persistent to be isolated, I was very persistent and could be isolated as radical crystals. The ESR spectra of nondeuterated and partially deuterated 1-3 radicals were measured, and the spin density distributions were estimated from the hyperfine coupling constants. Ab initio molecular orbital calculations were made for 1 to discuss the spin density distribution in more detail. Single-crystal X-ray crystallographic analysis was performed for one radical. Magnetic properties were measured for isolated four radicals with a SQUID. Two radicals showed ferromagnetic interaction, and analyses of (x)T vs T plots with the one-dimensional regular Heisenberg model gave 2J/k(B) =5.8 and8.6K. The remaining two radicals showed antiferromagnetic interaction. Analyses of the (x)T vs T plots with the Curie-Weiss law or dimer model gave Θ = -1.4 K and 2J/k(B) = -1370K. The strong antiferromagnetic interaction could be explained in terms of the X-ray crystallographic results.
