190961-69-4Relevant academic research and scientific papers
Design of photonic liquid crystal materials: Synthesis and evaluation of new chiral thioindigo dopants designed to photomodulate the spontaneous polarization of ferroelectric liquid crystals
Dinescu, Liviu,Maly, Kenneth E.,Lemieux, Robert P.
, p. 1679 - 1686 (2007/10/03)
Irradiation of a ferroelectric S(c)* liquid crystal phase induced by the photochromic dopants (R,R)-6,6'-bis(2-octyloxy)-5,5'-dinitrothioindigo and (R,R)-5,5'-dichloro-6,6'-bis(2-octyloxy)thioindigo at λ=514 and 532 nm, respectively, causes an increase in spontaneous polarization (P(s)) by a factor ranging from 1.4 to 4.0. This increase in P(s) is achieved without concomitant destabilization of the S(c)* phase, and is consistent with an increase in transverse dipole moment of the thioindigo core as a result of trans-cis photoisomerization. The contribution of the thioindigo core towards P(s) is achieved through stereo-polar coupling with the chiral side-chains, which is enhanced by the presence of the nitro and chloro substituents.
Compounds and methods for doping liquid crystal hosts
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, (2008/06/13)
This invention provides chiral thioindigo compounds for doping smectic liquid crystal hosts, wherein the compounds modulate a chiral bulk property of an induced chiral smectic liquid crystal phase upon irradiation at a wavelength in the visible range. Modulation of the chiral bulk property is effected by reversible trans-cis photoisomerization of the compound upon irradiation. The compounds maintain their rod-like shape in both isomeric forms, and hence do not destabilize the chiral smectic liquid crystal phase. Compounds according to the invention are useful in optical devices such as optical switches, displays, and memory.
