Showing papers by "Bing Xu published in 1993"

Rigid bowlic liquid crystals based on tungsten-oxo calix[4]arenes: host-guest effects and head-to-tail organization

Abstract: New methodologies for the creation of noncentrosymmetric structures in molecular solids and liquids are critical to the development of new materials with ferroelectric and second order nonlinear optical (NLO) Liquid crystalline methods are particularly attractive since liquid crystalline materials are easily deposited for device construction and are readily aligned.2 Bowl-shaped (bowlic) liquid crystals3 are natural noncentrosymmetric building blocks since a head-to-tail organization maximizes the interactions between bowlic cores. Columnar phases are also conductive to polar order since their symmetry does not readily accommodate antiferroelectric arrangement^.^^ We present herein a new type of columnar liquid crystal with a rigid bowlic core based on tungsten-oxo calix[4]arene complexes. These complexes display mesophases of unusually high stability and novel host-guest effects, which suggests that head-to-tail organization occurs in the mesomorphic state. Calix[4]arenes are a well-known class of bowlic compounds which have been of interest due to their ease of preparation and propensity to exhibit host-guest comple~es.~ We have synthesized

Calixarene-based transition metal complexes and photonic devices comprising the same

Abstract: Calixarene-based, noncentrosymmetric transition metal complexes that exhibit large second order nonlinear optical and related electro-optical properties are provided, as are materials and devices comprising the same.