Fluorescent and photo-optical properties of hydrogen-bonded polymer liquid-crystalline composites based on derivatives of stilbazole and crown ethers

New hydrogen-bonded photochromic stilbazole- and crown-ether-containing polymer LC composites are prepared and characterized. A smectic homopolymer with p-oxybenzoic groups, a nematic homopolymer carrying phenylmethoxy benzoate groups, and a nematic copolymer containing p-oxybenzoic and phenylmethoxy benzoate groups are synthesized and used as polymer matrices for these composites. The phase behavior and photo-optical properties of LC composites of various compositions are studied. A marked difference is observed in the fluorescence spectra for hydrogen-stabilized LC mixtures and model mixtures not forming hydrogen bonds. This effect is explained by the reversible transfer of proton of carboxyl groups involved in hydrogen bonding. It is shown that the complexation of crown-ether-containing groups of LC composites with potassium ions leads to a dramatic reduction in the intensity of fluorescence. This phenomenon may be used for creation of a new generation of sensors for metal ions.