Molecular Motion Probes Radicals in Zeolites

The X-band ESR spectrum of EtsN at 300 K consists of an intense and sharp hyperfine (hf) septet of 2.0 mT splitting with two weak additional lines at each wing which have almost the same splitting as the septet (Fig. 6.8(a)). The intense septet corresponds to the mi = 0 band of the central N(7 = 1) atom and is attributed to the isotropic /t/splittings due to six equivalent /3-hydrogens of N(o()—[C( )H2— C(y)H3]3. The weak wing lines have a spectral feature characteristic of /t/anisotropy 

The ESR spectrum of EtBN at 77 K corresponds to a rigid-limit (Eig. 6.8(b)). The spectmm consists of a broad hf sextet whose two outer-most lines have a 4.4 mT splitting, but the central quartet has a splitting of 3.6 mT. The quartet is attributed to three equivalent hydrogens, one from each /3-methylene group, and the weak 

---