High sensitivity of electron paramagnetic resonance spectra of spiro-fused dinitroxide probe to dynamical and structural characteristics of the matrix was experimentally demonstrated. Geometrical parameters describing the relative position and orientation of nitroxide fragments of the biradical, as well as characteristics of dipolar and exchange interaction between the nitroxide moieties were determined from experimental spectra. Orientation order parameters of biradical dissolved in aligned smectic and supercooled smectic media determined by numerical simulation of the angular dependence of electron paramagnetic resonance spectrum show very high degree of orientation of the probe in the liquid-crystalline matrix.

实验证明了螺旋二硝基氧探针的电子顺磁共振谱对基体的动力学和结构特征具有很高的敏感性。从实验光谱确定描述双自由基的氮氧化物片段的相对位置和取向的几何参数，以及氮氧化物部分之间的偶极和交换相互作用的特征。通过电子顺磁共振波谱的角度依赖性的数值模拟确定的溶解在对准的近晶和过冷近晶介质中的双自由基的取向顺序参数表明，探针在液晶基质中的取向度非常高。