INCLUSION OF SPIN-LABELED MOLECULES IN THE SOLID PHASE OF CYCLODEXTRINS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们制备了β和伽马环糊精(CD)与几种自旋标记化合物：几种N-羟基硬脂酸、C8和C16脂肪酸的酯/酰胺与Temol/TEMPAMINE的包合物，并用170 GHz和X波段的高频ESR对其进行了研究。Cd晶体水合物的光谱表现出快速近理想的轴向旋转，对于十二烷基硬脂酸是绕Z轴旋转，对于TEMPO衍生物是绕X轴旋转。晶体水合物的脱水停止了羟基硬脂酸的Z-旋转，但对X-旋转化合物的动力学影响较小。这些谱可以在讲座和研讨会上用作ESR中各向异性运动影响的很好的说明性例子，以及高频ESR优异的定向分辨率。在高频，一旦在光谱中可以分辨出运动，就可以分辨出运动发生在哪个轴上。 固体Cd相分子的一个显著特征是在很低的温度下可检测到迁移率。高频ESR表明g张量值的平均值，因此，从20K开始的分子运动。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We prepared inclusion complexes of beta and gamma cyclodextrins (CD) with spin labeled compounds: several n-doxylstearic acids and esters/amides of C8 and C16 fatty acids with TEMPOL/TEMPAMINE and studied them by HF ESR at 170 GHz and X-Band. The spectra in CD crystallohydrate show patterns of fast near-ideal axial rotation, which is about Z-axis for doxylstearic acids and about X-axis for TEMPO derivatives. Dehydration of the crystallohydrate stops Z-rotation of doxystearic acids but has less effect on the dynamics of the X-rotating compounds. The spectra can be used at lectures and workshops as good illustrative examples for the effects of anisotropic motion in ESR and excellent orientation resolution of HF ESR. At HF, once motion is discernable in the spectrum, one can discern about which axis the motion occurs. A striking feature of molecular in the solid CD phase is detectable mobility at very low temperatures. HF ESR indicates averaging of the g-tensor values and, hence, molecular motion starting at 20K.