TRANS AND CIS ROTAMERIZATION IN AMPHIPHILIC CHOLESTERIC LIQUID-CRYSTALS WHERE THE CHIRAL DOPANT IS THE HYDROCHLORIDE OF DECYL-L-PROLINE

Data from a previous study, where a reversal in the sense of the helic al twist in an amphiphilic cholesteric liquid crystal (ACLC) is induce d by the chiral dopant the hydrochloride of decyl-L-proline, is taken and its interpretation extended. The interpretation involves trans and cis conformers resulting from hindered rotation. The C-13 NMR data is used to determine the rotamer populations, which facilitates the calc ulation of the twisting powers for the individual rotamers. The twisti ng powers of the trans and cis rotamers are found to be 3900 +/- 900 c m(-1) and -650 +/- 150 cm(-1) respectively.