Improved Properties of Ferroelectric Liquid Crystals from Palladium β-Diketone Complexes

✍ Scribed by María Jesús Baena; Dr. Pablo Espinet; Dr. María Blanca Ros; Dr. José Luis Serrano; Dr. Amaya Ezcurra

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 347 KB
• Volume: 32
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.199312031

✦ Synopsis

The nonequivalence of the two halves of the dimer caused by the chiral center becomes apparent only at -20 "C in the 'H NMR spectrum: at this temperature the t w o nonequivalent Haatoms give rise to two very close but distinct singlets. Modified complexes of type 4 have been measured. and frequency doubling was observed: J. Zyss, I. Ledoux, J. Martin, J. Buey, P. Espinet, unpublished.

[a];" of the complexes ( c =1, CH,CI,): 4a, -8.8; 4b, -8.0; 4c, -7.7. R. Cano. Bull. Soc. Fr. Mineral. Cristallogr. 1967, 90. 333. Cholesteric mixtures containing about 20 wt% of the chiral additive were placed hetween a flat glass slide and a spherical lens. Both surfaces were rubbed to provide a uniform planar anchoring. The disclination rings in the sample, which correspond to steps ofp/2. were observed using a polarizing microscope. The pitch p was calculated from the diameters of these rings.