서지주요정보
키랄성을 갖는 대칭구조의 액정에 관한 연구 = Chiral siamese twin liquid crystals
서명 / 저자 키랄성을 갖는 대칭구조의 액정에 관한 연구 = Chiral siamese twin liquid crystals / 최승엽.
발행사항 [서울 : 한국과학기술원, 1986].
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4104036

소장위치/청구기호

학술문화관(문화관) 보존서고

MAC 8627

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초록정보

The commonly accepted structural requirement for liquid crystals is possession of a rigid central core with flexible (usually alkyl or alkoxy) or polar tails. Recently known is that the reversed structural arrangement, that is, two rigid mesogenic biphenyl terminal groups connected by a flexible alkoxy or alkyl chains, also exhibit liquid crystal properties. These new type of liquid crystal structures are known as "Siamese Twins". To investigate the influence of the chiral center in the central flexible chain upon the liquid crystal properties of the Siamese twins, we synthesized 1,6-bis(4,4'-cyanobiphenyloxy)-3-methylhexane. We also synthesized 1,6-bis(4,4'-cyanobiphenyl)hexane and 1,6-bis(4,4'-acetylbiphenyl)hexane for the purpose of comparison. 1,6-Bis(4,4'-cyanobiphenyloxy)-3-methylhexane was prepared from 4-Hydroxy-4'-cyanobiphenyl and 3-methyl-1,6-hexanedibromide in 70% yield, and purified by recrystallization from ethyl acetate. 1,6-Bis(4,4'-cyanobiphenyl)hexane was prepared from 1,6-bis(4,4'-bromobiphenyl) hexane and cuprous cyanide in dry DMF. The product was isolated by column chromatography in 30% yield. 1,6-Bis(4,4'-acetylbiphenyl)hexane was prepared from 1,6-bis(biphenyl)hexane and acetic anhydride by Friedel-Craft acylation in dry carbon disulfide at 12℃. Column chromatography of the reaction mixture gave 20% yield of the titled compound. Examination of these materials on the hot stage of polarizing microscope and DSC data revealed that 1,6-bis(4,4'-cyanobiphenyloxy)-3-methylhexane produced smectic. A phase rather than nematic phase of cholesteric phase. 1,6-Bis(4,4'-cyanobiphenyl)hexane and 1,6-bis(4,4'-acetylbiphenyl)hexane did not exhibit any liquid crystalline properties.

서지기타정보

서지기타정보
청구기호 {MAC 8627
형태사항 [iii], 44 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Seung-Yeob Choi
지도교수의 한글표기 : 조의환
지도교수의 영문표기 : I-Whan Cho
학위논문 학위논문(석사) - 한국과학기술원 : 화학과,
서지주기 참고문헌 : p. 42-44
주제 Chirality.
Siamese twins.
액정. --과학기술용어시소러스
카이랄 대칭성. --과학기술용어시소러스
편광 현미경. --과학기술용어시소러스
Liquid crystals.
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