Spin Distribution and Chemical Reactivity of sigma-Free Radicals

1.本文用ESR方法研究了（4-叔丁基苯硫基）（4-甲氧基苯基-1- ^<13>C）二氮烯、（4-叔丁基苯硫基）（4-氯苯基-1- ^<13>C）二氮烯、（4-叔丁基苯硫基）（1-萘基）二氮烯及其1- ^<13>C，1- ^ C<13>-1- ^<15>N，2，4-d_2-标记化合物和（4-叔丁基苯硫基）（2-萘基）二氮烯的H，^<13>C，N核的hfs常数。在电极氧化下，用亚硝基苯-1- ^ C进行ESR实验<13>，我们观察到一种未知自由基的氮氧自由基。使用更多的稀溶液，实验将继续进行。三重共振ESR技术对4-甲氧基苯二氮烯基的研究因瞬态浓度低而不成功.通过参考9种氯代芳烃（A）和18种二芳基硫醚（E）的化学位移，完成了（芳基）（芳硫基）二氮烯CIDNP光谱中E线（δ-135）和A线（δ-133ppm）的鉴别。CIDNP中4-甲氧基苯基二氮烯的1-C和2-C的His常数符号可能彼此相反，1-C与2-C的相对强度比为-30：1。尝试了氘代四甲基亚硝基苯对4-甲氧基苯基重氮烯的捕获。未确认二氮烯基捕获的氮氧自由基，但检测到较高g值的未知自由基的氮氧自由基与芳基苯基氮氧自由基的比例约为1.5。四比一点五芳基二氮烯基1-C和1-N上的自旋密度可以解释芳基相对于二氮烯基从取代甲苯中夺氢的速率。

1. (4-t-Butylphenylthio)(4-methoxyphenyl-1- ^<13>C)diazene, (4-t-butylphenylthio)(4-chlorophenyl-1- ^<13>C)diazene, (4-t-butylphenylthio)(1-naphthyl)diazene, its 1- ^<13>C, 1- ^<13>C-1- ^<15>N, 2, 4-d_2-labled compounds, and(4-t-butylphenylthio)(2-naphthyl)diazene were studied by the ESR method to determined hfs constants of H, ^<13>C, and N nuclei. In the ESR experiments by using nitrosobenzene-1- ^<13>C under electrode oxidation we observed a nitroxide of unknown free radical. Using more dilute solutions the experiment will be continued.2. TRIPPLE resonance ESR technique was unsuccessful to 4-methoxyphenyldiazenyl because of low concentration of the transients.3. Identification of E lines(delta-135)and A lines(delta-133 ppm)in CIDNP spectra from(aryl)(arylthio)diazenes was completed by reference to chemical shifts of authentic 9 chloroarenes(A)and 18 diaryl sulfides(E).Signes of his constants of 1-C and 2-C of 4-methoxyphenyldiazenyl in CIDNP is probably reversal to each other with relative intensity ratio-30 : 1 for 1-C to 2-C.4. Trapping of 4-methoxyphenyldiazenyl by deuterio-tetramethylnitrosobenzene was attempted. The diazenyl-trapped nitroxide was not confirmed, but a nitroxide of unknown radical of higher g-value was detected together with arylphenylnitroxide in a ratio ca. 4 : 1.5. Spin densities on 1-C and 1-N of aryldiazenyl may explain a rate of H-abstraction by aryl radical relative to diazenyl from substituted toluenes.