Enantiodiscrimination of Inherently Chiral Thiacalixarenes by Residual Dipolar Couplings.

Inherently chiral compounds, such as calixarenes, are chiral due to a nonplanar three-dimensional (3D) structure. Determining their conformation is essential to understand their properties, with nuclear magnetic resonance (NMR) spectroscopy being one applicable method. Using alignment media to measure residual dipolar couplings (RDCs) to obtain structural information is advantageous when classical NMR parameters like the nuclear Overhauser effect (NOE) or -couplings fail.

Poly-γ-p-Biphenylmethyl-Glutamate as Enantiodifferentiating Alignment Medium for NMR Spectroscopy with Temperature-Tunable Properties.

The use of anisotropic NMR parameters-especially residual dipolar couplings (RDCs)-offers access to additional structural information and, therefore, alignment media required for this approach are under a continuous development. Here, we present poly-γ-p-biphenylmethyl-glutamate (PBPMG) as a new versatile enantiodifferentiating alignment medium. The thermoresponsive properties of this polymer allowed for RDC measurements of more than one orientation within the same sample at different temperatures.