Enantiomeric visualization using proton-decoupled natural abundance deuterium NMR in poly(γ-benzyl-l-glutamate) liquid crystalline solutions

2H NMR Studies on Two‐Homopolypeptide Lyotropic Enantiodiscriminating Mesophases: Experimental Quantification of Solute–Fiber Affinities

“…For samples of toluene and phenol (9-14), we used the same amount of solute and polypeptide, but about 554 mg of CHCl 3 . For samples of (AE )-phenethyl alcohol (15)(16)(17), we used about 10 mg of solute, about 100 mg of polypeptide, and about 540 mg of CHCl 3 . For samples 1-7 of bza, the polypeptide DPs were 1352 (PBLG) and 1100 (PCBLL).…”

“…Natural-abundance deuterium NMR experiments are advantageous because we can simultaneously examine all nonequivalent 2 H sites in a molecule without any isotopic labeling. [2,3,17] Besides, recording the proton-coupled 13 C spectrum allows the determination of the magnitude of one-bond 13 C-1 H couplings, and also the sign of dipolar couplings, assuming that the 1 J CH > 0. Indeed, as the two-order parameters S CH and S CD can be assumed equal, then the ratio j Dn Q / 1 D CH j lies approximately in the range 10-13.…”

NMR spectroscopy in partially oriented phases. Routine2H NMR of small to medium sized molecules

“…4 With this it is also possible to distinguish diastereomers with remote chiral centers. 6 For this purpose, they used a chiral synthetic polypeptide, poly--benzyl-L-glutamate (PBLG), with a molecular weight range of 120 000-150 000 and an organic solvent such as chloroform, THF or dichloromethane as co-solvent.…”

An Easy and Scalable Method for the Partial Alignment of Organic Molecules for Measuring Residual Dipolar Couplings

“…[9][10][11][12][13] Liquid-crystalline phases, however, have the disadvantage that a minimal concentration is necessary and therefore a minimal alignment of the molecules in a sample is introduced, which strongly limits the applicability of standard methods for the measurement of coupling constants. [12] An alternative is given by strain induced alignment in a gel (SAG), which is independent of the magnetic field and scalable over a wide range.…”