Influence of hemicyanine dye structures on spectral properties of their supramolecular complexes with amylose

Heuer, William B.; Lee, H. S.; Kim, Oh‐Kil

doi:10.1039/a808359b

Cited by 11 publications

(7 citation statements)

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“…Because hemicyanine dyes exhibit negative solvatochromism and charge transfer occurs upon excitation, the ground state is more polar than the excited state. Therefore, the pyridinium cation has a greater influence on the spectral shift in a polar medium at the ground state relative to the neutral dimethylamino group in the excited state . In the case of a hemicyanine dye, a red shift in the absorption band occurs when the pyridinium moiety resides within the hydrophobic cavity, which is nonpolar in nature.…”

Section: Resultsmentioning

confidence: 99%

“…Both donor and acceptor moieties of DASPC22 are expected to be included in the hydrophobic cavities, experiencing a similar environment. It is obvious that, in this situation, there would be very little influence on the ICT process in the excited state, leading to a negligible shift in the absorption spectrum . The long alkyl chain is attached to the pyridinium nitrogen in such a way that the charged pyridinium moiety is included completely within the nonpolar host cavity in the inclusion state.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the pyridinium cation has a greater influence on the spectral shift in a polar medium at the ground state relative to the neutral dimethylamino group in the excited state. 71 In the case of a hemicyanine dye, a red shift in the absorption band occurs when the pyridinium moiety resides within the hydrophobic cavity, which is nonpolar in nature. Therefore, the excited state will have stronger influence on the intramolecular chargetransfer (ICT) process.…”

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confidence: 99%

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Study of the Binding Interactions of a Hemicyanine Dye with Nanotubes of β-Cyclodextrin and Effect of a Hofmeister Series of Potassium Salts

et al. 2014

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The photophysical properties of a hemicyanine dye, 4-[4-(dimethylamino)styryl]-1-docosylpyridinium bromide (DASPC22), have been studied in homogeneous media of pure solvents and mixed solvents using UV–vis absorption and fluorescence spectroscopies. These properties were explored to study the binding interactions between DASPC22 and nanotubes of β-cyclodextrin (β-CD) using UV–vis absorption, steady-state fluorescence and fluorescence anisotropy, and time-correlated single-photon-counting (TCSPC) fluorescence measurements of the dye. DASPC22 molecules form H-aggregates in pure water. β-CD forms a simple inclusion complex (1:2 stoichiometry) below its critical aggregation concentration (cac) by encapsulating the chromophoric part of the dye. The H-aggregate dissociates significantly to the monomeric form of the dye only when the nanotubes of β-CD molecules start to form above its cac. The dye molecule exists in its monomeric form upon inclusion of its chromophoric part along with the aliphatic tail inside the hydrophobic nanotubular cavity of β-CD. A 350-fold increase in fluorescence intensity of DASPC22 inside the nanotubular cavities formed by an 8 mM concentration of β-CD compared to the fluorescence intensity in the form of a simple inclusion complex was observed. The effects of a Hofmeister series of potassium salts, namely, KClO4, KI, KCl, and KF, in both low and high concentration ranges on the binding strength between host and guest molecules were studied. Salts in their very low concentration ranges enhanced the stability of the host–guest complexes, resulting in a further increase in fluorescence intensity. The fluorescence properties can be tuned by the selective addition of potassium salts with various anions. The tuning of the optical properties of the dye in β-CD nanochannels could help materials scientists to develop novel supramolecular materials.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

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Study of the Binding Interactions of a Hemicyanine Dye with Nanotubes of β-Cyclodextrin and Effect of a Hofmeister Series of Potassium Salts

et al. 2014

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“…α-Sexithiophene ( 556 in Figure ) adopts chirally twisted conformations in a hydrophobic chiral channel generated in helical polysaccharides, such as right-handed triple-stranded helical SPG and left-handed single-stranded, partially carboxymethylated amylose (CMA) in aqueous solutions. , The inclusion complexes show ICDs with Cotton effect signs opposite to each other, suggesting an opposite handed twisted structure of 556 which reflects the helical handedness of the polysaccharides . A series of 4-(4-(dimethylamino)styryl)pyridine-type dye molecules ( 557 ), − oligo( p -phenylenevinylene) ( 558 ), and achiral ladder polysilane ( 559 ) also exhibit an optical activity when encapsulated in the helical cavity of amylose. , …”

Section: Helical Polymers and Their Assembliesmentioning

confidence: 99%

Supramolecular Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions

et al. 2016

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In this review, we describe the recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of their formations with unique chiral phenomena, such as amplification of chirality during the dynamic helically assembled processes, properties, and specific functionalities, some of which have not been observed in or achieved by biological systems. In addition, a brief historical overview of the helical assemblies of small molecules and remarkable progress in the synthesis of single-stranded and multistranded helical foldamers and polymers, their properties, structures, and functions, mainly since 2009, will also be described.

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“…Beispielsweise wurde die Fluoreszenzintensität des Cyaninfarbstoffs 27 (der DASP-C 16 ähnelt, siehe Schema 11) in verschiedenen DMSO-Wasser-Gemischen mit oder ohne Zugabe von Amylose studiert (Abbildung 23). [184] Die Fluoreszenzintensität des hydrophoben freien Farbstoffs sinkt mit steigendem Wasseranteil, wie man es für die fortschreitende Aggregation erwartet. In Gegenwart von Amylose bleibt die Fluoreszenzintensität bei > 75 % DMSO konstant, was zeigt, dass der Farbstoff unter diesen Bedingungen nicht komplexiert ist.…”

Section: Photolumineszenzeffizienzunclassified

Isolierte molekulare Drähte

2007

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In den erstaunlich unterschiedlichen Strukturen, die bisher als “isolierte molekulare Drähte” (insulated molecular wires, IMWs) beschrieben wurden, zeigt sich, wie vielfältig die Ansätze zur elektrisch‐chemischen Isolierung auf molekularer Ebene sind. Gemeinsam verdeutlichen diese Systeme die Bedeutung von Einkapselungsstrategien bei der Entwicklung optoelektronischer Materialien und organischer Halbleiter. Dieser Aufsatz beleuchtet die Synthese und die strukturelle Charakterisierung von IMWs. Struktur‐Eigenschafts‐Beziehungen sollen zudem erklären, wie eine Isolierung die Leistungsmerkmale eines molekularen Drahtes verbessern kann. Wir konzentrieren uns auf drei IMW‐Arten: Polyrotaxane, polymerumhüllte π‐Systeme und dendronisierte Polymere. Die Eigenschaften dieser Systeme werden mit denjenigen von konjugierten Polymeren verglichen, die in mesoporöse Netzwerke und Zeolithe eingefädelt sind. Der Einschluss molekularer Drähte verstärkt so unterschiedliche Eigenschaften wie Lumineszenz, elektrische Transportgrößen und die chemische Beständigkeit, sodass Anwendungen in Elektrolumineszenzdisplays, Sensoren und der photochemischen Wasserstofferzeugung denkbar werden.

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Influence of hemicyanine dye structures on spectral properties of their supramolecular complexes with amylose

Cited by 11 publications

References 9 publications

Study of the Binding Interactions of a Hemicyanine Dye with Nanotubes of β-Cyclodextrin and Effect of a Hofmeister Series of Potassium Salts

Study of the Binding Interactions of a Hemicyanine Dye with Nanotubes of β-Cyclodextrin and Effect of a Hofmeister Series of Potassium Salts

Supramolecular Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions

Isolierte molekulare Drähte

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