Determination of molecular orientation distribution of a stable paramagnetic probe in oriented 4-cyano-4’-n-pentylbiphenyl

Understanding the effects of targeted modifications on the 1 : 2 Choline And GEranate structure

“…The simulations for TEMPO in BTMAAOC used the same g - and A -values as for CAOC, with a small, homogeneous shift to the g -vector (+0.0002). 59 Similar to CAOC, in BTMAAOC the rotation of TEMPO appears less restricted than that of 4-hydroxy-TEMPO (Fig. 11), both in the liquid crystalline (for the polar populations, τ c = 0.45 ns for TEMPO versus τ c = 1.3 for 4-hydroxy-TEMPO) and isotropic phases ( τ c = 0.04 ns for TEMPO versus 0.29 ns for 4-hydroxy-TEMPO).…”

Simulation of Rigid-Limit and Slow-Motion EPR Spectra for Extraction of Quantitative Dynamic and Orientational Information

“…In the present chapter, we describe the model-free method of determining of orientation distribution function [70][71][72][73][74][75][76]. The method is based on the expansion of the determined function in a series of orthonormal functions with variable coefficients.…”

“…The application of the suggested method is demonstrated below on the examples of spin probes in liquid crystals, polymer matrices, and supercooled glasses [73][74][75][76][77].…”

“…In Figure 16(a), one can see some EPR spectra of the standard spin probe TEMPOL ( Figure 3) in nematic liquid crystal 5CB (4-n-amyl-4-cyanobiphenyl) aligned by the magnetic field of the EPR spectrometer [73,74]. The spectra were recorded at T = 77K (in liquid nitrogen) at various angles between the symmetry axis of the sample and the magnetic field of the EPR spectrometer.…”

Molecular Orientational Order of Nitroxide Radicals in Liquid Crystalline Media

“…On the other hand, it is known that compact piperidine spin probes (TEMPONE, TEMPOL, etc.) also demonstrate considerable orientational ordering in LC media in spite of an almost circular, nonelongated molecular shape. − Therefore, the shape of the dopant molecules is not the only factor that governs molecular orientation of the probes doped into liquid crystals. Thus, it is necessary to ascertain real orientation axis of the guest molecule, i.e., the molecular axis that is ordered in the aligned liquid crystal to the maximum extent.…”