1. Design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. Heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder

New liquid crystals have been synthesized and their transition phases have been studied. It was found that a family of (-)-2-methyl 2R,3S-epithio-4'-alkoxybiphenyl pentanoates are liquid crystals but a similar system of ( + )-2-methyl 2S,3R-epoxy-4'-alkoxybiphenyl pentanoates are not. Of t...

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Main Author: Wang, Xin
Language:English
Published: University of British Columbia 2010
Subjects:
Online Access:http://hdl.handle.net/2429/28353
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spelling ndltd-UBC-oai-circle.library.ubc.ca-2429-283532018-01-05T17:44:36Z 1. Design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. Heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder Wang, Xin Liquid crystals New liquid crystals have been synthesized and their transition phases have been studied. It was found that a family of (-)-2-methyl 2R,3S-epithio-4'-alkoxybiphenyl pentanoates are liquid crystals but a similar system of ( + )-2-methyl 2S,3R-epoxy-4'-alkoxybiphenyl pentanoates are not. Of the liquid crystals, MEAOBP-S-7 exhibits smectic A and B phases; MEAOBP-S-8 and MEAOBP-S-9 show only the smectic B phases; MEAOBP-S-10 shows a monotropic chiral smectic C phase. This distinction is in agreement with the argument that the internal dipolar interaction of the molecule plays an important role in determining liquid crystalline behaviour of this ester system. The reaction rate of the racemization of optically active binaphthyl can be moderately increased in the presence of finely divided titanium dioxide (anatase) powder. This first order catalyzed reaction has a proportional relationship with the concentrations of both the catalyst and the binaphthyl. The catalyzed reaction can be poisoned permanently by the addition of polynuclear aromatic compounds and the poisoning efficiency is dependent of the number of the aromatic rings the poison posesses. By comparison with the catalyzed racemizations of binaphthyl by platinum, nickel and carbon and from the kinetic and mechanistic studies on the titanium dioxide catalyzed racemization, we conclude that (1) this catalytic phenomenon is common among heterogeneous inorganic solids and can be extended to other simple reactions, and that (2) the mechanism of the catalysis probably involves a radical anion intermediate. Science, Faculty of Chemistry, Department of Graduate 2010-09-09T21:09:31Z 2010-09-09T21:09:31Z 1987 Text Thesis/Dissertation http://hdl.handle.net/2429/28353 eng For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use. University of British Columbia
collection NDLTD
language English
sources NDLTD
topic Liquid crystals
spellingShingle Liquid crystals
Wang, Xin
1. Design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. Heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder
description New liquid crystals have been synthesized and their transition phases have been studied. It was found that a family of (-)-2-methyl 2R,3S-epithio-4'-alkoxybiphenyl pentanoates are liquid crystals but a similar system of ( + )-2-methyl 2S,3R-epoxy-4'-alkoxybiphenyl pentanoates are not. Of the liquid crystals, MEAOBP-S-7 exhibits smectic A and B phases; MEAOBP-S-8 and MEAOBP-S-9 show only the smectic B phases; MEAOBP-S-10 shows a monotropic chiral smectic C phase. This distinction is in agreement with the argument that the internal dipolar interaction of the molecule plays an important role in determining liquid crystalline behaviour of this ester system. The reaction rate of the racemization of optically active binaphthyl can be moderately increased in the presence of finely divided titanium dioxide (anatase) powder. This first order catalyzed reaction has a proportional relationship with the concentrations of both the catalyst and the binaphthyl. The catalyzed reaction can be poisoned permanently by the addition of polynuclear aromatic compounds and the poisoning efficiency is dependent of the number of the aromatic rings the poison posesses. By comparison with the catalyzed racemizations of binaphthyl by platinum, nickel and carbon and from the kinetic and mechanistic studies on the titanium dioxide catalyzed racemization, we conclude that (1) this catalytic phenomenon is common among heterogeneous inorganic solids and can be extended to other simple reactions, and that (2) the mechanism of the catalysis probably involves a radical anion intermediate. === Science, Faculty of === Chemistry, Department of === Graduate
author Wang, Xin
author_facet Wang, Xin
author_sort Wang, Xin
title 1. Design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. Heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder
title_short 1. Design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. Heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder
title_full 1. Design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. Heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder
title_fullStr 1. Design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. Heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder
title_full_unstemmed 1. Design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. Heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder
title_sort 1. design and synthesis of new chiral units for potentially ferroelectric liquid crystals : liquid crystals containing a thiiran unit. 2. heterogeneous catalysis of the racemization of 1,1'-binaphthyl by titanium dioxide powder
publisher University of British Columbia
publishDate 2010
url http://hdl.handle.net/2429/28353
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