Spontaneous aggregation of octaalkoxyphthalocyanine metal complexes at an air–water interface

Matsuzawa, Yoko; Seki, Takahiro; Ichimura, Kunihiro

doi:10.1016/s0040-6090(97)00006-0

Cited by 30 publications

(31 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At the water interface exist liquid crystals that orient horizontally (flat‐on) and that orient vertically (edge‐on). Regarding the phenomenon, many authors have reported on the study of orientation behavior of the discotic liquid crystal at the air‐water interfaces 32–41. According to them, the benzene condensed ring–based triphenylene ring and truxene ring with long‐chain alkyls orient edge‐on (vertical to the interface) and the heterocyclic ring–based phthalocyanine, triaryl melamine, and azacrown rings orient flat‐on (horizontal to the interface).…”

Section: Horizontal Orientation Of Discotic Liquid Crystal31mentioning

confidence: 99%

Orientation Control and Fixation of Discotic Liquid Crystal

Kawata

2002

The Chemical Record

164

View full text Add to dashboard Cite

We established hybrid, horizontal, vertical, and vertical-twisted alignment of discotic liquid crystals on web-coating thin film. Newly developed materials are the photopolymerizable discotic liquid crystals, in order to fix desired novel alignment, the alignment promoters that deposit toward air surface during web coating, followed by drying of solvent, and then accomplish desired alignment of liquid crystals, the alignment layers that promote desired alignment of liquid crystals from the substrate side and the chiral agents, which have strong chiral powers in small amounts. Hybrid aligned discotic liquid crystal thin film has proven quite effective in expanding the viewing angle of thin film transistor liquid crystal displays.

show abstract

Section: Horizontal Orientation Of Discotic Liquid Crystal31mentioning

confidence: 99%

Orientation Control and Fixation of Discotic Liquid Crystal

Kawata

2002

The Chemical Record

164

View full text Add to dashboard Cite

show abstract

“…The direction of shifts of the spectra depends on many factors: for example, the central complexing cation 32 and length of the hydrocarbon chain of the peripheral substituent. 33 A characteristic feature of the spectrum of the LBF of the ruthenium complex is the appearance of a band in the near IR region at ~880 nm. This band is absent from the spectra of solutions of both the ligand and (R 4 Pc)Ru(CO)(MeOH) complex.…”

Section: Resultsmentioning

confidence: 99%

Monolayers and Langmuir-Blodgett films of crown-substituted phthalocyanines

et al. 2004

View full text Add to dashboard Cite

Tetra 15 crown 5 phthalocyanine ligand and its ruthenium complex with axial CO and MeOH groups were synthesized. The properties of their monolayers and Langmuir-Blodgett films were studied. In the case of the ligand, monolayer films of molecular associates are formed. The compatibility of the ligand and stearic acid in a mixed binary monolayer was established. Stearic acid improves the ligand distribution over the water surface and results in the formation of monolayer associates immobilized in its matrix. The condensation effect of Na + cations on the mixed monolayers was found. The ruthenium complex (R 4 Pc)Ru(MeOH)(CO) forms stable true monolayers. The macrocycle planes in stacking are inclined relatively to the normal to the subphase surface by an angle of 25°. The Langmuir-Blodgett films of the complex were established to have redox peaks. A high electrochemical stability of the Langmuir-Blodgett films and a high electroactivity of phthalocyanine rings were demon strated. It was shown by impedance spectroscopy that the binding of Na + and К + ions by Langmuir-Blodgett films of the (R 4 Pc)Ru(MeOH)(CO) complex results in an increase in the impedance values in a region of medium frequencies by three and five times, respectively.Discotic compounds forming columnar structures in block and dispersions attract researchers´ attention due to a possibility of their assembling to form linear transport systems (channels) extended at a supramolecular level. Phthalocyanines are typical representatives of these com pounds. Significant interest in these objects is caused by their unique properties important from both theoretical and practical points of view. These are the lability of the electronic structure of a macrocycle, formation of com plexes with the most part of metals, easiness in introduc ing peripheral substituents and axial ligands of different nature, multistability, etc. 1,2 A possibility of self assem bling of phthalocyanines to form linear associates favors the creation of related functional supramolecular systems with a uniform orientation. In almost all cases, ultrathin films assembled by the Langmuir-Blodgett method con sist of phthalocyanine nanotubes, whose axes are parallel to the support surface. However, for many practical pur poses it seems important that axes of discotic columns would be arranged along a direction close to the normal or at a small angle to the normal. In this case, planes of phthalocyanine macrocycles would be parallel to the sup port. Such a molecular structure of a film should provide a more efficient transport over channels, for instance, when phthalocyanine is used as a mediator of electron transfer to an electrode in various, including enzymatic, reactions, in redox processes for developing chemical sen sors, in photoelectric devices, etc. However, this orienta tion has not been accomplished yet in Langmuir-Blodgett films (LBF), because it is difficult to obtain this orienta tion in LBF precursors (monolayers on the water surface) for several reasons: amphiphility is absent, ...

show abstract

“…It has been demonstrated that the air-water interface favors the neutral over the charged form in acid-base equilibrium. 2,4 However, no varying degree of protonation has been shown with the surface coverage at the air-water interface. This change in the OEP acid-base equilibrium differs from the usual behavior in the bulk solution, as will be explained later.…”

Section: Resultsmentioning

confidence: 99%

“…The domains of PH 2 were stable and floated on the water surface. 4 When one of them came into the viewing region of the microscope, an intense signal of PH 2 appeared. It has been reported that a large number of molecules exhibit a collective-diffusion behavior due to micro-Brownian motion.…”

Section: Resultsmentioning

confidence: 99%

Spectral Fluctuation and Heterogeneous Distribution of Porphine on a Water Surface

Slyadnev

Inoue

et al. 1999

Langmuir

View full text Add to dashboard Cite

Using a confocal fluorescence microscope, we found a significant temporal fluctuation in the fluorescence spectrum of porphine molecules on the water surface. The spectra fluctuated when the accumulation time was 300 ms and the pH was within a certain range. No fluctuation was observed with a longer accumulation time (36 s) or on a solid surface. The present observation indicates that the distribution of porphine on the water surface is heterogeneous and that the Brownian motion of the surface species induces spectral fluctuation. A neutral form of porphine produces domains at a higher surface coverage.

show abstract

Spontaneous aggregation of octaalkoxyphthalocyanine metal complexes at an air–water interface

Cited by 30 publications

References 32 publications

Orientation Control and Fixation of Discotic Liquid Crystal

Orientation Control and Fixation of Discotic Liquid Crystal

Monolayers and Langmuir-Blodgett films of crown-substituted phthalocyanines

Spectral Fluctuation and Heterogeneous Distribution of Porphine on a Water Surface

Contact Info

Product

Resources

About