Dinse Klaus-Peter, Kato Tatsuhisa, Hasegawa Shota, Hashikawa Yoshifumi, Murata Yasujiro, Bittl Robert
Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany.
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Magn Reson (Gott). 2020 Sep 10;1(2):197-207. doi: 10.5194/mr-1-197-2020. eCollection 2020.
Using pulsed electron paramagnetic resonance (EPR) techniques, the low-temperature magnetic properties of the NO radical being confined in two different modified open -derived cages are determined. It is found that the smallest principal value , being assigned to the axis of the radical, deviates strongly from the free electron value. This behaviour results from partial compensation of the spin and orbital contributions to the value. The measured values in the range of 0.7 yield information about the deviation of the locking potential for the encaged NO from axial symmetry. The estimated 17 meV asymmetry is quite small compared to the situation found for the same radical in polycrystalline or amorphous matrices ranging from 300 to 500 meV. The analysis of the temperature dependence of spin relaxation times resulted in an activation temperature of about 3 K, assigned to temperature-activated motion of the NO within the modified open -derived cages with coupled rotational and translational degrees of freedom in a complicated three-dimensional locking potential.
利用脉冲电子顺磁共振（EPR）技术，测定了限制在两种不同修饰的开放式衍生笼中的NO自由基的低温磁性。结果发现，分配给自由基轴的最小主值与自由电子值有很大偏差。这种行为是由于自旋和轨道对值的贡献部分补偿所致。在0.7范围内测得的值提供了有关笼中NO锁定势偏离轴对称的信息。与在多晶或非晶基质中发现的相同自由基的情况（300至500 meV）相比，估计的17 meV不对称性相当小。对自旋弛豫时间的温度依赖性分析得出约3 K的活化温度，这归因于NO在具有复杂三维锁定势的修饰开放式衍生笼内的温度激活运动，该运动具有耦合的旋转和平移自由度。
