- Synthesis of diphenyl-diacetylene-based nematic liquid crystals and their high birefringence properties
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We synthesized two series of diphenyl-diacetylene (DPDA)-based materials with alkoxy and alkyl tails of length m (DPDA-OCm and DPDA-Cm, respectively), and measured their nematic-phase birefringence (Δn) as a function of wavelength and temperature. We found that Δn decreases with an increase in m, possibly by a dilution effect of the low-Δn alkyl tail. Further, of the two series, Δn was found to be relatively higher in the DPDA-OCm materials, with the highest value of 0.4 obtained for DPDA-OC1 at 550 nm at 10 °C below the isotropic-to-nematic transition temperature. Further, we observed the temperature dependence for Δn, which is proportional to the order parameter (s). From extrapolation to s = 1 (the perfect orientation state), it is speculated that the DPDA-O moiety has the potential to afford a very large Δn of 0.9. The Royal Society of Chemistry 2012.
- Arakawa, Yuki,Nakajima, Shunpei,Ishige, Ryohei,Uchimura, Makoto,Kang, Sungmin,Konishi, Gen-Ichi,Watanabe, Junji
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supporting information; experimental part
p. 8394 - 8398
(2012/07/28)
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- Optically active compound and photosensitive resin composition
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A photoactive compound is used in combination with a photosensitizer, represented by the following formula (1): A?[(J)m?(X-Pro)]n ??(1) wherein A represents a hydrophobic unit comprising at least one kind of hydrophobic groups selected from a hydrocarbon group and a heterocyclic group, J represents a connecting group, X-Pro represents a hydrophilic group protected by a protective group Pro which is removable by light exposure, m represents 0 or 1, and n represents an integer of not less than 1. The protective group Pro may be removable by light exposure in association with the photosensitizer (especially, a photo acid generator), or may be a hydrophobic protective group. The hydrophilic group may be a hydroxyl group or a carboxyl group. The photoactive compound has high sensitivity to a light source of short wavelength beams, for resist application, therefore, the photoactive compound is advantageously used for forming a pattern with high resolution.
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