A microwave-assisted and environmentally benign approach to the synthesis of near-infrared fluorescent pentamethine cyanine dyes

Owens, Eric A.; Bruschi, Nicholas; Tawney, Joseph G.; Henary, Maged

doi:10.1016/j.dyepig.2014.07.035

Cited by 34 publications

(23 citation statements)

References 16 publications

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“…The relative instability of indolium salts is well-documented [ 26 ] and our attempts to purify compounds 3 by silica gel chromatography or recrystallisation were unsuccessful. In light of this, and given that our alkylation reactions were relatively clean, crude indolium salts 3 were then condensed with 3-methoxy-5-nitrosalicylaldehyde ( 5 ) to give the required spiropyrans C n SP ( Table 1 ).…”

Section: Resultsmentioning

confidence: 99%

Synthesis and metal binding properties of N-alkylcarboxyspiropyrans

Perry¹,

Kousseff²

2017

Beilstein J. Org. Chem.

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Spiropyrans bearing an N-alkylcarboxylate tether are a common structure in dynamic, photoactive materials and serve as colourimetric/fluorimetric cation receptors. In this study, we describe an efficient synthesis of spiropyrans with 2–12 carbon atom alkylcarboxylate substituents, and a systematic analysis of their interactions with metal cations using 1H NMR and UV-visible spectroscopy. All N-alkylcarboxyspiropyrans in this study displayed a strong preference for binding divalent metal cations and a modest increase in M2+ binding affinity correlated with increased alkycarboxylate tether length.

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Section: Resultsmentioning

confidence: 99%

Synthesis and metal binding properties of N-alkylcarboxyspiropyrans

Perry¹,

Kousseff²

2017

Beilstein J. Org. Chem.

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“…General methods and reagents for the preparation of cyanines have been recently reviewed by Henary and Leviz,50 and by Panigrahi et al,27 including the use of microwave (MW) assisted reactions 51,52…”

Section: Polymethine Dyesmentioning

confidence: 99%

Polymethine Dyes in Hybrid Photovoltaics: Structure–Properties Relationships

et al. 2016

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Polymethine dyes as photosensitizers for dye‐sensitized solar cells (DSCs) are reviewed. The review provides a summary of design strategies, the main synthetic routes, and the optical and photovoltaic properties of polymethine dyes applied in hybrid photovoltaics. In particular, we focus on cyanine and squaraine dyes and their structure–properties relationships, highlighting the role of the active molecule design on device performance.

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“…The synthetic method for obtaining the desired compounds 12-14 occurs similar to the Knoevenagel condensation, but in this case, the condensation reactions take place between the bis iminic pentamethine salts 11a-c with compound 5 using sodium acetate as the base and isopropyl alcohol (HPLC grade) as the solvent under reflux (Scheme 1). To minimize the photooxidation processes that can be prejudicial to the stability of these structures [36], the synthesis was performed in the dark with the use of amber glassware 5 International Journal of Photoenergy and under N 2 atmosphere. The final compounds were purified by precipitation and obtained in moderate yields (~50%).…”

Section: Resultsmentioning

confidence: 99%

Guest-Host Interactions in Symmetrical Carboxy Heptamethine Cyanine Dyes-Titanium Dioxide Systems: Synthesis, Theoretical Calculations, Aggregation Properties, and Application in Dye-Sensitized Solar Cells

Duarte

Oliveira

Toldo

et al. 2021

International Journal of Photoenergy

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In this work, the role of deoxycholic acid (DCA) as a coadsorbent was investigated in the sensitization of mesoporous TiO2 layers (host) with symmetrical carboxy heptamethine cyanine dyes (guest). Different approaches have been tested, aimed at reducing the H-aggregation and minimizing the competition between cyanine molecules and DCA for active sites of the host, thus improving solar cell efficiency. Heptamethine cyanines containing carboxylic anchoring groups were obtained with good yields. The cyanines present UV-Vis absorption in methanol and dimethylformamide solutions ascribed to fully allowed electronic transitions ( 1 π π ∗ ), as well as fluorescence emission in the NIR region, with any evidence of aggregations in both ground and excited states. TD-DFT calculations were also performed in order to study the geometry and charge distribution of these compounds in their ground and excited electronic states. Solid-state photophysics indicates that the cyanines showed excellent adsorption on TiO2, which can be justified by the presence of the -COOH moieties in the structure. Photophysical measurements have revealed the best concentrations of dye and DCA, which resulted in efficient inhibition of cyanine H-aggregates on the TiO2 surface in addition to allow large dye loading. HOMO and LUMO energy levels of the dyes were identified by cyclic voltammetry, showing oxidation and reduction potentials within acceptable limits for application as a photosensitizer in dye-sensitized solar cells (DSSCs) based on a TiO2 mesoporous photoanode. Assembled DSSCs have shown a large improvement of the electrical parameters and efficiency when a balance between dye aggregation and the competition to the host active sites was reached.

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A microwave-assisted and environmentally benign approach to the synthesis of near-infrared fluorescent pentamethine cyanine dyes

Cited by 34 publications

References 16 publications

Synthesis and metal binding properties of N-alkylcarboxyspiropyrans

Synthesis and metal binding properties of N-alkylcarboxyspiropyrans

Polymethine Dyes in Hybrid Photovoltaics: Structure–Properties Relationships

Guest-Host Interactions in Symmetrical Carboxy Heptamethine Cyanine Dyes-Titanium Dioxide Systems: Synthesis, Theoretical Calculations, Aggregation Properties, and Application in Dye-Sensitized Solar Cells

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