Near‐Resonant Nonlinear OpticalProperties of Pseudoisocyanine J‐Aggregates in Langmuir‐BlodgettLayers

Feller, K.‐H.; Gadonas, R.; Moebius, D.

doi:10.1155/1997/95890

Cited by 6 publications

(5 citation statements)

References 22 publications

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“…J -aggregates absorbing at 578 nm were observed in hydrophobic Langmuir-Blodgett films [46]. Energy of absorbed light is influenced by the effects of the electrostatic interaction of PIC cations with counterions [47], which can be different in hydrated environments or at the interface.…”

Section: Absorption Spectroscopymentioning

confidence: 99%

Spectral properties and structure of the J-aggregates of pseudoisocyanine dye in layered silicate films

Bujdák

Iyi

2008

Journal of Colloid and Interface Science

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Section: Absorption Spectroscopymentioning

confidence: 99%

Spectral properties and structure of the J-aggregates of pseudoisocyanine dye in layered silicate films

Bujdák

Iyi

2008

Journal of Colloid and Interface Science

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“…Molecular aggregates of dyes have attracted much attention due not only to their relevance to the light-harvesting and primary charge separation steps in photosynthesis but also to their interesting properties and great potential in technological applications. In particular, the structures and optical properties of J-aggregates of dyes have been extensively investigated under various conditions − from the viewpoint of applications to the materials for spectral sensitization, optical storage, , and nonlinear optics. − Molecules in J-aggregates are arranged one-dimensionally or as in a brick−stone work. When chromophores form J-aggregates and a delocalized excitonic state is formed, a new and sharp optical absorption band (J-band) appears, which is positioned at longer wavelengths with respect to the absorption band of the monomer.…”

Section: Introductionmentioning

confidence: 99%

“…In particular, the structures and optical properties of J-aggregates of dyes have been extensively investigated under various conditions [1][2][3][4][5][6] from the viewpoint of applications to the materials for spectral sensitization, 7 optical storage, 8,9 and nonlinear optics. [10][11][12] Molecules in J-aggregates are arranged one-dimensionally or as in a brick-stone work. When chromophores form J-aggregates and a delocalized excitonic state is formed, a new and sharp optical absorption band (J-band) appears, which is positioned at longer wavelengths with respect to the absorption band of the monomer.…”

Section: Introductionmentioning

confidence: 99%

Brewster Angle Microscopic Observations of the Langmuir Films of Amphiphilic Spiropyran during Compression and under UV Illumination

et al. 2004

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The structure of the Langmuir film of an amphiphilic spiropyran, 1',3'-dihydro-3',3'-dimethyl-6-nitro-l'-octadecyl-8-(docosanoyloxyme thyl)spiro[2H-1-benzopyran-2,2'-(2H)-indole] (SP), is investigated using Brewster angle microscopy (BAM). The BAM observations show that the Langmuir film of SP can be roughly categorized into three regimes: a low-temperature regime at 7-13 degrees C; a medium-temperature regime at 23-30 degrees C; a high-temperature regime at 40 degrees C. The low-temperature regime is characterized both by the domains that are formed just after the spreading and by the onset of the surface pressure when the domains are merged together to form continuous trilayers. In the medium-temperature regime, a continuous monolayer film is formed after the solvent evaporation, followed by the growth of "embryos" with compression. Around the phase transition point, the "embryos" serve as the "nucleation sites" of the circular trilayer domains. The characteristic features of the high-temperature regime are similar to the ones of the medium-temperature regime except for the absence of a steep rise in surface pressure after the plateau region and the absence of the circular trilayer domains. UV illumination of the Langmuir films leads to the isomerization of SP into merocyanine (MC). However, J-aggregates of MC are formed only when the circular trilayer domains are present. On the basis of the above results, we present a phase diagram of the Langmuir film of SP. The structure and photoreaction depend strongly on the phase of the Langmuir film, indicating that the area/molecule is not the only decisive parameter.

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“…J-aggregates of dye molecules have been extensively investigated under various conditions − from the viewpoint of the application to the spectral sensitization, optical storage, , and nonlinear optics. − J-aggregates in Langmuir and Langmuir−Blodgett (LB) films are of considerable interest because the films have well-defined structures with low-dimensional nature. ,,,− When chromophores form J-aggregates and the delocalized excitonic state is formed, the absorption band is red-shifted and very narrow with a small Stokes shift compared to the case in which chromophores are in a monomeric state.…”

Section: Introductionmentioning

confidence: 99%

Light-Induced J-Aggregation of Merocyanine in Langmuir and Langmuir−Blodgett Films

et al. 2002

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The structures and photoreactions of the Langmuir and LB films of an amphiphilic spiropyran, 1′,3′-dihydro-3′,3′-dimethyl-6-nitro-1′-octadecyl-8-(docosanoyloxymethyl)spiro[2H-1-benzopyran-2,2′-(2H)-indole] (SP) are investigated. A chloroform solution of SP at a concentration of 0.1 mM is spread on the water surface. When the Langmuir film of SP is compressed on a subphase at 30°C and a phase transition takes place, the monolayer changes into a mosaic structure where bilayer domains are buried in the monolayer. When the Langmuir films are illuminated with UV light, SP is isomerized to merocyanine (MC). J-aggregates of MC are formed at high temperatures and at high surface pressures where the bilayer domains are formed. The Langmuir films of SP are transferred as LB films onto solid substrates at 30°C. The LB films consist of the bilayer domains with a diameter of 10 to 20 µm and a height of 4 to 5 nm. Three-dimensional structures are present in almost all the bilayer domains. Room-temperature illumination of the LB films with UV light produces the J-aggregation of MC with the development of dendritic structures starting from the three-dimensional structures in the domains. These dendrites consist of the J-aggregates. Molecules are aligned radially in the dendrites. When the LB film is illuminated at 7°C, the J-aggregation of MC does not proceed. All these results indicate that the criteria of the J-aggregation of MC in the Langmuir and LB films are the presence of the bilayer domains and the nucleation sites with the mobility of the molecules large enough for the morphological change necessary for the J-aggregation.

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Near‐Resonant Nonlinear OpticalProperties of Pseudoisocyanine J‐Aggregates in Langmuir‐BlodgettLayers

Cited by 6 publications

References 22 publications

Spectral properties and structure of the J-aggregates of pseudoisocyanine dye in layered silicate films

Spectral properties and structure of the J-aggregates of pseudoisocyanine dye in layered silicate films

Brewster Angle Microscopic Observations of the Langmuir Films of Amphiphilic Spiropyran during Compression and under UV Illumination

Light-Induced J-Aggregation of Merocyanine in Langmuir and Langmuir−Blodgett Films

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