Design and synthesis of an achiral ferroelectric smectic liquid crystal

Design and synthesis of a bent-core mesogen possessing the achiral ferroelectric SmAPF phase is reported. The design approach is based upon the discovery of Sadashiva and Reddy, et al. that bent-core mesogens possessing only one tail gave biaxial SmA phases shown to be antiferroelectric (SmAPA). The SmAPA phase shows antiferroelectric layer stacking with synclinic layer interfaces, as expected based upon typical behavior seen in most bent-core mesogens. In order to obtain the target ferroelectric phase, several tails known to allow the formation of anticlinic layer interfaces were incorporated into the basic Sadashiva/Reddy structure. These tails are thought to suppress out of layer fluctuations, thereby removing the strong entropically driven tendency for synclinic layer interfaces, and allowing formation of anticlinic layer stacking driven by a more subtle, and unknown, factor in the free energy of the system. In the event, the tricarbosilane-terminated alkoxy tail proved effective, providing the first known low molar mass SmAPF material.

[1]  Harry J. Coles,et al.  Ferroelectric and antiferroelectric low molar mass organosiloxane liquid crystals , 1998 .

[2]  Optical investigations on the biaxial smectic- A phase of a bent-core compound. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[3]  P. Bos,et al.  The pi-Cell: A Fast Liquid-Crystal Optical-Switching Device , 1984 .

[4]  N. Clark,et al.  A Ferroelectric Liquid Crystal Conglomerate Composed of Racemic Molecules , 2000, Science.

[5]  M. Nakata,et al.  Charge controlled, fixed optic axis analog (“v-shaped”) switching of a bent-core ferroelectric liquid crystal , 2004 .

[6]  C. Tschierske,et al.  Cyclic ureas as novel building blocks for bent-core liquid crystals. , 2007, Chemical communications.

[7]  C. Tschierske,et al.  The carbosilane unit as a stable building block for liquid crystal design: a new class of ferroelectric switching banana-shaped mesogens. , 2004, Chemical communications.

[8]  N. V. Madhusudana,et al.  Biaxial smectic A phase in homologous series of compounds composed of highly polar unsymmetrically substituted bent-core molecules , 2002 .

[9]  N. Clark,et al.  Macroscopic Orientation Patterns in Smectic-CFilms , 1980 .

[10]  N. Clark,et al.  Spontaneous Ferroelectric Order in a Bent-Core Smectic Liquid Crystal of Fluid Orthorhombic Layers , 2011, Science.

[11]  E. Soto-Bustamante,et al.  Ferroelectricity in Achiral Liquid‐Crystal Systems , 2004 .

[12]  N. Clark,et al.  Control of molecular orientation in electrostatically stabilized ferroelectric liquid crystals. , 2003, Physical review letters.

[13]  J. Watanabe,et al.  Distinct ferroelectric smectic liquid crystals consisting of banana shaped achiral molecules , 1996 .

[14]  Clark,et al.  Spontaneous formation of macroscopic chiral domains in a fluid smectic phase of achiral molecules , 1997, Science.

[15]  D. Walba Ferroelectric Liquid Crystal Conglomerates , 2004 .

[16]  N. Clark,et al.  Chiral Isotropic Liquids from Achiral Molecules , 2009, Science.

[17]  G. Pelzl,et al.  Experimental evidence for an achiral orthogonal biaxial smectic phase without in-plane order exhibiting antiferroelectric switching behavior. , 2001, Physical review. E, Statistical, nonlinear, and soft matter physics.

[18]  P. Cladis,et al.  Symmetry and defects in the CM phase of polymeric liquid crystals , 1992 .