Molecular aspects of squaraine dyes aggregation and its influence on spectroscopic properties

Kaczmarek‐Kędziera, Anna; Kędziera, Dariusz

doi:10.1007/s00214-016-1971-0

Cited by 16 publications

(11 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1, it is possible to verify that in aqueous media the four dyes tend to form aggregates, which is evidenced by the presence of two slightly overlapping bands, one of which is relative to the monomer and the other to the formed aggregates. This trend is already widely reported in the literature (42)(43)(44)(45) and is associated with the low solubility of squaraine dyes in aqueous media. The aggregates can be classified into J-aggregates and H-aggregates, which is related to the type of alignment of the transition dipole moments on adjacent molecules (46,47).…”

Section: Photophysical Studiessupporting

confidence: 66%

Squaraine Dyes Derived from Indolenine and Benzo[e]indole as Potential Fluorescent Probes for HSA Detection and Antifungal Agents

Gomes

Ferreira

Boto

et al. 2022

Photochem & Photobiology

View full text Add to dashboard Cite

Four squaraine dyes derived from 2,3,3-trimethylindolenine and 1,1,2-trimethyl-1H-benzo[e]indole with different combinations of barbituric groups attach to the central ring, having ester groups and alkyl chains in the nitrogen atoms of heterocyclic rings were synthesized. These dyes were fully characterized, and their photophysical behavior was studied in ethanol and phosphate-buffered solution. Absorption and emission bands between 631 and 712 nm were detected, with the formation of aggregates in aqueous media, which is typical of this class of dyes. Tests carried out with 1,3diphenylisobenzofuran allowed us to verify the ability of the dyes to produce singlet oxygen. The interaction of synthesized dyes with human serum albumin (HSA) was also evaluated, being demonstrated a linear correlation between fluorescence intensity and protein concentration. The antifungal potential of the dyes against the yeast Saccharomyces cerevisiae was evaluated using a broth microdilution assay. In order to test the photosensitizing capacity of the synthesized dyes, tests were carried out in the dark and with irradiation, using a custom-built light-emitting diode that emits close to the absorption wavelength of the studied dyes. The results showed that the interaction of dyes with HSA and the antifungal activity depends on the different structural modifications of the dyes.

show abstract

Section: Photophysical Studiessupporting

confidence: 66%

Squaraine Dyes Derived from Indolenine and Benzo[e]indole as Potential Fluorescent Probes for HSA Detection and Antifungal Agents

Gomes

Ferreira

Boto

et al. 2022

Photochem & Photobiology

View full text Add to dashboard Cite

show abstract

“…The lack of such a central amino group in DMASQ determines the nature and stability of the obtained aggregates and significantly modifies the absorption spectrum changes upon aggregation. For DASQ simple batochromic shift and increase of the intensity is noticed upon aggregation, while for DMASQ analyzed in the present study, additionally strong changes of the spectral shape and additional bands are observed for staircase stacked aggregates 44 .…”

Section: Discussionmentioning

confidence: 39%

“…The nature of the intermolecular interactions in the aggregates of the squaraines is crucial from the point of view of their photophysical properties. These have been previously studied by the current authors for two squaraine systems, namely DMASQ and 2,4-bis(aminophenyl) squaraine (DASQ) 44 . They have been chosen as the exemplary molecules representing different hydrogen-bond donating/accepting ability: DASQ in contrast to DMASQ possesses the strong hydrogen bond donor.…”

Section: Discussionmentioning

confidence: 99%

Nature of intermolecular interaction in squaraine dimers

Kaczmarek‐Kędziera

Żuchowski

Kędziera

2020

Sci Rep

Self Cite

View full text Add to dashboard Cite

Squaraine dyes are known for their particular optical properties. They exhibit intense photochemically stable fluorescence in usually (near) infra red region that can be quenched by intermolecular interactions. Moreover, even the centrosymmetric dyes feature non-zero second harmonic generation upon aggregation. Therefore, the detailed knowledge of the squaraine dye interaction nature both in homogenic aggregates and with other species present in the environment can be of importance for the design of new materials of desired properties. In the present study, interaction in squaraine dimers is investigated with quantum chemistry tools. Four structures: two stacked and two hydrogen-bonded are analyzed in terms of supermolecular approach and symmetry-adapted perturbation theory. MP2C/aug-cc-pVTZ supermolecular calculations confirm the particular stability of the stacked dimers and the favoured dispersion attraction for the long-displaced system.

show abstract

“…For the monoclinic phase, instead, the quinoidic character of the anilino-rings is more pronounced. The transition dipole moment for the S 0 → S 1 molecular transition is along the long molecular axis of the squaraine core. − To correlate molecular packing and the through space coupling of transition dipole moments within the excitonic dimers, we now follow the molecular dimer picture of Kasha-aggregates, Figure .…”

Section: Resultsmentioning

confidence: 99%

Spotlight on Excitonic Coupling in Polymorphic and Textured Anilino Squaraine Thin Films

Balzer

Kollmann

Schulz

et al. 2017

Crystal Growth & Design

View full text Add to dashboard Cite

Structural diffraction analysis of an anilino squaraine with branched isobutyl side chains shows crystallization into two polymorphic structures in the bulk and in spin-casted thin films. We observe multipeaked and pleochroic absorption spectra being blue-(red)-shifted for the monoclinic (orthorhombic) polymorph. We understand the packing as Coulombic molecular H-(J)-aggregates supporting Davydov splitting. Pictures of projected Davydov components in oriented thin films fit well to polarization resolved spectro-microscopy and crossed-polarized light microscopy investigations. By comparison with literature on anilino squaraines with linear alkyl side chains, we point out a general trend for steering the thin film excitonic properties by simple side chain and/or processing condition variation. Combined with the ability to locally probe the direction of transition dipole moments, this adds value to the rational design of functional thin films for optoelectronic applications, especially envisioning ultrastrong light–matter interactions.

show abstract

Molecular aspects of squaraine dyes aggregation and its influence on spectroscopic properties

Cited by 16 publications

References 43 publications

Squaraine Dyes Derived from Indolenine and Benzo[e]indole as Potential Fluorescent Probes for HSA Detection and Antifungal Agents

Squaraine Dyes Derived from Indolenine and Benzo[e]indole as Potential Fluorescent Probes for HSA Detection and Antifungal Agents

Nature of intermolecular interaction in squaraine dimers

Spotlight on Excitonic Coupling in Polymorphic and Textured Anilino Squaraine Thin Films

Contact Info

Product

Resources

About