Proton-Pumping by Purple Membrane in Combined Multilayers with a Phthalocyanine Derivative

Ogawa, Kimiya; Kinoshita, Sho-ichi; Nakahara, Hiroyuki; Fukuda, Kiyoshige

doi:10.1246/cl.1990.2025

Cited by 4 publications

(1 citation statement)

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“…By application to photofunctional materials, such morphological changes in lamellar solid films can be induced by the photochemical transformations of the incorporated guest molecules . The photofunctional properties of such solid films are significant when considering their potential to the development of photonic devices such as nonlinear optical systems − and photon-mode memory storage systems − and in applications using the magnetic susceptibility effect. − In previous work, we reported the [2 + 2] photocyclodimerization of cinnamic acid incorporated in solid films of dioctadecyldimethylammonium bromide (DODAB) and focused on the effects of the phase transition on the cyclodimerization efficiency . The photochemistry was found to change dramatically with the change from cyclodimerization to E − Z photoisomerization with heat treatment above 52 °C, which is the phase-transition temperature of the DODAB films before and during photolysis.…”

Section: Introductionmentioning

confidence: 99%

Self-Assembled Thin Solid Films of Dioctadecyldimethylammonium Cinnamate Lamella Units That Control the Photostationary State of E−Z Photoisomerizations

et al. 2002

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UV illumination of dioctadecyldimethylammonium cinnamates (C18 trans-cin and C18 cis-cin) was found to result in the E-Z photoisomerization of the cinnamate moieties in self-assembling multilamella films. In the present case, a common photostationary state (pss), which can usually be observed in solution, was not seen in the photolysis of the self-assembled material films of C18 trans-cin and C18 cis-cin having a bimolecular (bilayer)-unit lamellar structure. Both the E-and Z-isomers are difficult to isomerize and exhibit different E/Z ratios, 73:27 and 10:90, respectively, even under prolonged UV irradiation. However, the same E/Z ratio (15:85) could be attained at the pss from either isomer in a monolayer-unit structure. The E/Z ratios were found to change abruptly upon heat treatment at around 55 °C before photoisomerization, implying a thermal structural change in the films. Analysis of X-ray diffraction, differential scanning calorimetry, and polarized IR and UV-vis spectroscopic investigations have indicated that the solid films have a characteristic multilamellar structure consisting of bilayer units when they are cast on the silica glass without heat treatment above 55 °C. Moreover, the solid films preheated to 80 °C were composed of an interdigitated monolayer unit having a loose packing structure. This result is in contrast to the bilayer-unit structure of the solid films where E-Z photoisomerization of both isomers is suppressed.

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