Two new mesogenic homologous series of liquid crystalline naphthalene derivatives with different central linkages: 2- Naphthyl-4-n-alkoxybenzoates (I) and trans-2-Naphthyl -4-n -alkoxycinnamates(II), have been synthesized and characterized by a combination of elemental analysis and standard spectroscopic methods. Twelve compounds have been synthesized in both the series I and II. In series I, methoxy to n-pentyloxy derivatives are non mesogenic, n-hexyloxy to n-hexadecyloxy derivatives exhibit monotropic nematic mesophase. Smectic A mesophase commences from n-decyloxy derivatives as a monotropy and persist up to the last member synthesized. All the 12 compounds of series II exhibit mesomorphism. Methoxy to n-propyloxy derivatives exhibit monotropic nematic mesophse, and n-butyloxy to n-tetradecyloxy derivatives exhibit enantiotropic nematic mesophase. n-Hexayloxy to n-hexadecyloxy derivatives also exhibit enantiotropic smectic A mesophase. The mesomorphic properties of present series were compared with each other and with a structurally related mesogenic homologous series to evaluate the effects of central linkage on mesomorphism.
Indium(III) chloride as a new, highly efficient, and versatile catalyst for acylation of phenols, thiols, alcohols, and amines
作者:Asit K. Chakraborti、Rajesh Gulhane
DOI:10.1016/s0040-4039(03)01641-1
日期:2003.8
Indium(III) chloride efficiently catalyses the acylation of structurally diverse phenols, alcohols, thiols, and amines undersolventfree conditions. Acid sensitive alcohols are smoothly acylated without competitive side reactions. Acylation of 2-hydroxynaphthalene is carried out with carboxylic acids adopting the mixed anhydride protocol using trifluoroacetic anhydride.
Novel photostabilizers, UV absorbers, and methods, of photostabilizing compositions
申请人:Bonda A. Craig
公开号:US20060257338A1
公开(公告)日:2006-11-16
Polymers containing one or more novel photoactive moieties, sunscreen compositions including a mixture of a photoactive compound and a polymer containing one or more photoactive moieties are described herein. Also disclosed are methods for stabilizing a sunscreen composition, methods of filtering out ultra-violet light from a substrate by the addition of one or more of the foregoing polymers, methods accepting the triplet excited state energy with one or more of the foregoing polymer, and methods of increasing the UV-A Protective Value are described herein.
NOVEL PHOTOSTABILIZERS, UV ABSORBERS, AND METHODS OF PHOTOSTABILIZING COMPOSITIONS
申请人:Bonda Craig A.
公开号:US20110033396A1
公开(公告)日:2011-02-10
Polymers containing one or more novel photoactive moieties, sunscreen compositions including a mixture of a photoactive compound and a polymer containing one or more photoactive moieties are described herein. Also disclosed are methods for stabilizing a sunscreen composition, methods of filtering out ultra-violet light from a substrate by the addition of one or more of the foregoing polymers, methods accepting the triplet excited state energy with one or more of the foregoing polymer, and methods of increasing the UV-A Protective Value are described herein.