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Volume 49, Issue 5
Displaying 1-17 of 17 articles from this issue
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Yasushi YOKOYAMA, Yukio KURITA1991 Volume 49 Issue 5 Pages 364-372
Published: May 01, 1991
Released on J-STAGE: January 28, 2010
JOURNAL FREE ACCESS“Fulgides” is the name of succinic anhydrides with two substituted methylidene groups, at least one of which is a (substituted) arylmethylidene group. Fulgides show a photochromic property between open (colorless) and closed (colored) forms with no thermal transformation, and are therefore expected to be used as advanced optical photomemory materials. In this review, a brief history of research on fulgides, general synthetic methods with experimental details, general methods of photoreactions both in solutions and in matrices, methods of analysis of photoreactions to obtain quantum yields, and steric and electronic effects of substituents of fulgides on their photochromic properties, are described.View full abstractDownload PDF (1231K) -
Masahiro IRIE1991 Volume 49 Issue 5 Pages 373-382
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSAlthough photochromic compounds have potential ability for use in optical memory media, the compounds still await practical applications. The limitation is due to the lack of suitable compounds which fulfill the requirements for the reversible recording media. Among the requirements, more important ones are thermal stability, fatigue resistant property, and sensitivity at diode laser wavelengths (780-830 nm). The present paper proposes a guiding principle for the molecular design of thermally irreversible and fatigue resistant photochromic diarylethenes having the absorption bands at the diode laser wavelengths. According to the principle, more than 20 diarylethenes with heterocyclic rings were synthesized. Among the compounds, 2- (1, 2-dimethyl-5-methoxy-3-indolyl) -3- (2-cyano-3, 5-dimethyl-4-thienyl) maleic anhydride was found to undergo a thermally irreversible and fatigue resistant photochromic reaction to produce the closed-ring form having an absorption edge extending to 860 nm.View full abstractDownload PDF (1155K) -
Kunihiro ICHIMURA1991 Volume 49 Issue 5 Pages 383-391
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSA new type of photoresponsive liquid crystalline cells has been developed. The cells were constructed by putting a nematic liquid crystal between two glass plates modified with azobenzene monolayers, the photoisomerization of which induces reversible alignment change between the homeotropic and parallel modes. Detailed studies revealed that the factors affecting the photoregulation of the alignment involve the molecular structure and occupied area of the azobenzene unit and the coexistence of long alkyl chain. Derivatives of stilbene and α-hydrazono-β-ketoester were found to be also effective for the photoregulation. This suggests that the reversible structural alteration between the rodlike and L-shaped photochromic units plays an essential role in the photoregulation. Discussion was made on the mechanism of the regulation, based on the relationship between the regulation efficiency and the surface energy change and on the spectroscopic alteration of photochromic units upon the contact with liquid crystalline molecules.View full abstractDownload PDF (1242K) -
Masataka NAKAMURA, Takashi TANIGUCHI1991 Volume 49 Issue 5 Pages 392-402
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSThe recent results concerning the synthesis and characteristic of spiro-oxazine compounds have been summarized.
The absorption bands of usual spiro-oxazine compounds are changed from colorless to colored form by irradiation of ultraviolet ray.
This mechanism is derived from the cleavage of oxazine ring. Such properties are dependent on, its chemical structure and surrounded matrix of spiro-oxazine compounds.
The chemical structure of this compound is similar to the well known spiropyran. But, spiro-oxazine compounds have been noticed recently, because of excellent high light-sensitivity and superior fatigue-resistant property. This compounds are already applied as photochromic lens, clothes and UV light checker.View full abstractDownload PDF (1013K) -
Keisuke TAKUMA, Yoshihiro IRIZATO1991 Volume 49 Issue 5 Pages 403-411
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSDichroic dyes of great practical value for liquid crystal displays (LCD) have been reviewed from the view point of the synthetic design. The function of dichroic guest dyes for LCD is dependent on the structure of substituent group and its position on chromophore. Some examples of the synthesis of anthraquinone, naphthoquinone and azo dyes with positive dichroism are shown. Dyes with negative dichroism are also described. Dyes for polarizing film are classified into two categories, i.e. for polyvinylalcohole matrix and for polyester matrix. Hydrophilic polyazo dyes with sulfonic acid groups are used in the former film, and for polyester matrix, hydrophobic dyes with long rod-like struture have been developed.View full abstractDownload PDF (853K) -
Hironobu YAMAMOTO, Seizo MIYATA1991 Volume 49 Issue 5 Pages 412-417
Published: May 01, 1991
Released on J-STAGE: January 28, 2010
JOURNAL FREE ACCESSFor the efficient second-order optical nonlinearity, the organic molecules must possess a large second-order hyperpolarizability β and also must crystallize into the lack of inversion center. We investigated a new molecular concept for noncentrosymmetric crystal structure. MO calculation by MOPAC AM 1 method demonstrated that the conformations of the methanediamine derivatives became lambda (Λ) -shape. The Λ-shape molecules formed easily noncentrosymmetric crystals because they could easily stack along one direction and thus exhibited Second-Harmonic Generation. The crystal structure analyses demonstrate that the Λ-shape molecules stack along one direction parallel to the crystal axis. This orientation is close to an optimum condition for maximizing crystal phase-matched nonlinearity. We demonstrate that methanediamine derivatives forming Λ-shape conformation are promising as efficient χ (2) materials.View full abstractDownload PDF (677K) -
Shuji OKADA, Hiro MATSUDA, Hachiro NAKANISHI1991 Volume 49 Issue 5 Pages 418-421
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSIn order to obtain the materials with large third-order nonlinear optical properties, polydiacetylenes (PDAs) having π-conjugation between polymer backbone and substituents were synthesized by proper crystal engineering. For the monomers for PDAs aromatic rings directly bound to main chain, one of two substituents bonding to the diacetylene (DA) moiety was selected from those of non-polymerizable symmetrical DA monomers. The highest χ (3) and the expected smallest dihedral angle between the polymer backbone and aromatic rings was already realized in one of the derivatives. PDAs with acetylenic and diacetylenic groups directly bound to the main chain were synthesized by polymerization of triyne and tetrayne compounds, respectively. The diacetylenic substituents of the polymers from the latter ones could be polymerized to give di (polydiacetylene) s, where two PDA polymer backbones were conjugated.View full abstractDownload PDF (450K) -
Masaru MATSUOKA1991 Volume 49 Issue 5 Pages 422-431
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSThere is currently extensive interest in the nonlinear optical (NLO) properties of organic compounds. Especially, the large second or third order NLO responses of materials are important in the fields of optical device technology.
This paper reviews the syntheses of organic NLO compounds to correlate the NLO responses with chemical structures. Molecular design by means of MO method and crystal engineering of NLO compounds are described in details. Nitroaniline and cyanostyryl derivatives with intramolecular charge-transfer chromophores have excellent NLO characteristics for second order NLO materials. On the other hand, large π-conjugated compounds, such as phthalocyanines, azo and azomethine dyes as well as π-conjugated polymers such as polydiacetylenes, polyphenylenevinylenes and polythiophenes are expected to have good third order NLO responses for optoelectronics devices.View full abstractDownload PDF (1323K) -
Yuzo ITOH1991 Volume 49 Issue 5 Pages 432-436
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSIn order to design organic nonlinear optical materials, several of theoretical calculations are necessary. Within the oriented gas model approximation, nonlinear susceptibilities of organic crystals can be calculated from hyperpolarizabilities of the molecule and the crystal structure. Molecular hyperpolarizabilities can be calculated very precisely by a molecular orbital method.
Theoretical calculations of hyperpolarizabilities of polymers, which are important as third-order nonlinear materials, were done considering their exciton states although there remained several problems to be solved.
The intermolecular interaction effects on hyperpolarizabilities were analysed by super molecule CPHF calculations of ab initio MO method.View full abstractDownload PDF (617K) -
Mitsuru UEDA, Hiroshi ITO1991 Volume 49 Issue 5 Pages 437-450
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSThe remarkable advancement of the microelectronics technology we have witnessed in the past decade are the direct result of the increase in the number of components per chip, which has been made possible by decreasing the minimum feature size on the chip. The feature size continues to shrink, placing stringent demands on resist materials that are used to fabricate minute integrated circuit devices. Reduction of the feature size to <0.5 μm will require the introduction of new lithographic technologies that employ short wavelength radiations such as deep UV (<300 nm), electron beams and X-rays. However, these high resolution lithographic technologies demand extremely high resist sensitivities for their economical operation. The concept of “chemical amplification” was proposed in 1982 to dramatically boost the sensitivity through incorporation of a gain mechanism in imaging chemistries. In this scheme, photochemically generated acids are used as catalyst to induce a cascade of subsequent chemical reactions in the resist film. The use of photochemical acid generators has not only provided high sensitivities but also offered high contrast and resolution, allowing the design of a whole new family of advanced resist systems, which are reviewed in this paper with emphasis placed on the chemistry responsible for imaging.View full abstractDownload PDF (1661K) -
Kazuhide SAIGO1991 Volume 49 Issue 5 Pages 451-455
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSSi-containing resists for a bi-layer system have been reported in the last decade. The molecular designs of the polymers suitable for the system must take four factors into considerations, such as 1) the polymers have high silicon content, 2) the polymers have a high Tg, 3) the polymers have a suitable radiation sensitive functional group, and 4) the polymers have narrow molecular weight distribution. The synthesis of Si-containing polymers with an allyl group and their applications to photoresists are reported.View full abstractDownload PDF (726K) -
Tadashi ENDO, Masahiko SHIMADA1991 Volume 49 Issue 5 Pages 456-466
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSIntercalation reaction can offer the ability to tailor the novel oraganic-inorganic hybrid materials in a nanometer scale. One of clays, smectite has been proved to be a proper candidate for confining some functional organic materials with a well-relurated conformation into its interlamellar. Optical properties of organic materials are sensitively affected by the surroundings of adsorption sites. Accordingly, the absorption and emisson spectra are observed with some changes of peak position and intensity.
Here, optical functions of hybrid materials, e.g. photochromic and photochemical reaction, metachromasy etc. are focused;and these issues are reviewed. Such information is much available for understanding the interfacial problems between organic and inorganic materials The design of optical function should be performed by controlling the discentralization and conformation of organic molecules in the gallery of smectite. Future prospects for new opto-hybrid materials are also discussed.View full abstractDownload PDF (1245K) -
Hiroyuki NOHIRA1991 Volume 49 Issue 5 Pages 467-474
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSIn order to prepare new types of ferroelectric liquid crystals (FLC) with a large spontaneous polarization and a short response time toward electric field, optically active compounds possessing a fluorinated asymmetric frame were synthesized utilizing optically active 2-fluoroalkanols prepared from R- (+) -1, 2-epoxyalkanes, or 1, 1, 1-trifluoro-2-octanol and 3-trifluoromethylalkanoic acids prepared by the optical resolution of their racemates.
The liquid crystals prepared from the above mentioned fluorinated compounds exhibited such remarkable FLC characteristics as a wide temperature range of the S*c phase, a large spontaneous polarization, and a short response time.
We now wish to describe the synthetic procedures and the mesomorphic properties of these new types of FLC.View full abstractDownload PDF (867K) -
Tetsuo KUSUMOTO, Tamejiro HIYAMA, Sadao TAKEHARA, Tadao SHOJI1991 Volume 49 Issue 5 Pages 475-485
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSNew chiral dopants having a chiral center directly connected to the core aromatic ring were designed and synthesized. Those discussed here are 1-arylethyl alkyl ethers, 2-arylpropanoates, O-acyl and O-alkylcyanohydrins, 2-arylalkanenitriles, aryl alkyl sulfoxides, α-aryl-γ-alkyl-γ-lactones, and 1-aryl-2-alkyl-1-cyanocyclopropanes. Ferroelectric liquid crystal mixtures doped with one of the compounds exhibited high spontaneous polarization (Ps). The sign of Ps was found to well correlate to the absolute configuration of the chiral center of the dopant.View full abstractDownload PDF (1040K) -
Kazuchika OHTA, Iwao YAMAMOTO1991 Volume 49 Issue 5 Pages 486-496
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSWe discuss recent advances of the molecular shapes of discotic liquid crystals and classification of the discophase structures. Then, we deals with “thermotropic discotic liquid crystals of organic transition metal complexes”. The new field of thermotropic liquid crystals of organic transition metal complexes was opened up independently by four pioneers in the latter half of the nineteen-seventies. Up to date, there are only seven types of discotic liquid crystals of organic metal complexes. These molecular structures and properties are reviewed.View full abstractDownload PDF (1257K) -
Naoyuki KOIDE1991 Volume 49 Issue 5 Pages 497-505
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSThis review includes recent advances of thermotropic liquid crystalline polymers (LCP). LCPs are classified into categories in function of their molecular structure such as main chain type, side chain type and combined type LCPs. Synthesis of main chain, side chain and combined type polymers are described. Main chain type LCPs are focused on the rigid polyesters owing to their application of high performance materials. The structure of rigid polyesters and the method of depression of transition temperature are given. Various kinds of side chain type LCPs are presented and discussed their functional properties.View full abstractDownload PDF (960K) -
Toyohiko ABE, Hiroyoshi FUKURO1991 Volume 49 Issue 5 Pages 506-513
Published: May 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSLiquid-crystal display (LCD) is a device utilizing the electrooptic property of aligned liquid-crystal (LC), and LC molecules are aligned homogeneously by the alignment film. The most of alignment film now in use industrially is polyimide (PI) thin film which should be rubbed. The required properties for alignment film vary with the types of LCD, however the most important is to give LC molecules planer alignment and suitable pretilt angle. The planer alignment property is supported to be related with the strain of thin film surface by rubbing, and pretilt angle is supported to be related with the physical and chemical properties of thin film surface. The control of surface tension and moleculer structure of thin film surface can be achieved by several moleculer designs of PI, and, by use of these PI for alignment film, the control of pretilt angle can be achieved. This method is very important for the commercial production of STN-mode LCD.View full abstractDownload PDF (960K)
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