J. Am. Chem. Soc. 1999, 121, 8229-8236
8229
Ferroelectric Liquid Crystals Induced by Atropisomeric Dopants: Dependence of the Polarization Power on the Core Structure of the Smectic C Host Despina Vizitiu, Carmen Lazar, Brian J. Halden, and Robert P. Lemieux* Contribution from the Department of Chemistry, Queen’s UniVersity, Kingston, Ontario, Canada K7L 3N6 ReceiVed March 24, 1999. ReVised Manuscript ReceiVed July 1, 1999
Abstract: A series of 11 chiral dopants with an atropisomeric core derived from 4,4′-dihydroxy-2,2′,6,6′tetramethyl-3,3′-dinitrobiphenyl were synthesized in optically pure form. These compounds were doped into five different smectic C (SC) liquid crystal hosts to induce a ferroelectric SC* liquid crystal phase, and the reduced polarization Po was measured as a function of the dopant mole fraction xd over the range 0.005 < xd e 0.05. The polarization power δp was found to strongly depend on the core structure of the SC host. For example, the dopant (+)-2,2′,6,6′-tetramethyl-3,3′-dinitro-4,4′-bis[(4-octyloxybenzoyl)oxy]biphenyl gave δp values of
