K. Radley et al., DECYL ESTER HYDROCHLORIDE OF ALANINE AS A CHIRAL DOPANT IN THE FORMATION OF AMPHIPHILIC CHOLESTERIC LIQUID-CRYSTALS, JOURNAL OF PHYSICAL CHEMISTRY B, 101(38), 1997, pp. 7404-7407
The decyl ester hydrochloride of the amino acid alanine is accessed as
a chiral dopant in amphiphilic cholesteric liquid crystal formation.
The achiral host detergents are alkylmethylammonium halides. The sense
and magnitude of the induced helix is found to be dependent on the ac
hiral host detergent. In the achiral host detergent tetradecyltrimethy
lammonium bromide (TDTMABr) the sense of the helical twist is found to
be positive, while in the other hosts the sense of the helical twist
is found to be negative. These results were interpreted in terms of th
e trans and cis rotamers associated with the ester linkage. C-13 NMR i
s used to measure the rotamer populations. Each rotamer is thought to
make an opposite but unequal contribution to the total twist.