Heterocycle-Substituted Stable Thioaminyl Radicals: Isolation, ESR Spectra, and Magnetic Properties<sup>1</sup>
作者:Yozo Miura、Tatsuya Tomimura、Yoshio Teki
DOI:10.1021/jo000901q
日期:2000.11.1
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 3 were not sufficiently persistent to be isolated, 1 was very persistent and could be isolated as radical crystals. The ESR spectra of nondeuterated and partially deuterated 1-3 radicals were measured,
N-[(2-苄基噻唑基)硫基]-(1),N-[(2-苯并恶唑基)硫基]-(2)和N-(2-嘧啶基硫基)-2,4,6-三取代-苯基氨基(3 )是由相应的胺氧化生成的。尽管2和3不够持久,无法分离,但1却非常持久,可以分离为自由基晶体。测量了未氘代和部分氘代的1-3个自由基的ESR光谱,并根据超精细偶合常数估算了自旋密度分布。进行了从头算的分子轨道计算,以更详细地讨论自旋密度分布。对一个自由基进行了单晶X射线晶体学分析。用SQUID测量了分离出的四个自由基的磁性能。两个自由基显示出铁磁相互作用,并用一维规则Heisenberg模型分析chiT与T曲线,得出2J / k(B)= 5.8和8.6K。其余两个自由基显示出反铁磁相互作用。使用居里-魏斯定律或二聚体模型对chiT vs T图进行分析得出theta = -1.4 K和2J / k(B)= -1370K。强反铁磁相互作用可以用X射线晶体学结果来解释。