Nonlinear optical properties of a new panchromatic series of water-soluble bicationic push-pull fluorophores

Mencaroni, Letizia; Bonaccorso, Carmela; Carlotti, Benedetta; Consiglio, Giuseppe; Elisei, Fausto; Fortuna, Cosimo G.; Spalletti, Anna; Cesaretti, Alessio

doi:10.1016/j.dyepig.2021.109620

Cited by 19 publications

(18 citation statements)

References 88 publications

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“…The spectral and fluorescence properties of the complexes are listed in Table 1. The investigated bications are all characterized by large Stokes shifts, resulting from important intramolecular rearrangement following excitation (charge transfer processes and possibly twisting) [36]; however, these shifts were found to reduce upon complexation indicating that the binding with polynucleotides impaired the freedom of the molecules.…”

Section: Spectrophotometric and Fluorimetric Investigation Of The Int...mentioning

confidence: 97%

“…As a rule, the interaction with nucleic acids caused the absorption spectrum to shift bathochromically. This could be the result of both the reduced polarity experienced by these negatively-solvatochromic dyes upon binding with nucleic acids [36], and the π-π interactions among aromatic portions, common to both the investigated compounds and their biological targets. An exception is compound 6 (Figure 3); in fact, its spectrophotometric titration with tRNA revealed an initial blue-shift of the absorption band at high r values, followed by the typical red-shift at higher tRNA concentrations.…”

Section: Spectrophotometric and Fluorimetric Investigation Of The Int...mentioning

confidence: 99%

“…All the titrations are reported in Figures 1-3 and S7-S11, while the binding constants (logK), calculated by processing fluorimetric titrations according to the Scatchard equation (McGhee-von Hippel formalism) [37], are reported in Table 2. In the case of compounds 1 and 2, which are highly fluorescent molecules in aqueous solution (Φ F = 0.16 and 0.36, respectively) [36], their fluorescence was found to undergo a significant decrease in the presence of tRNA (Figure 1 and Figure S7). In fact, their emission properties upon additions of ct-DNA and synthetic polynucleotides of defined composition had previously been studied and a fluorescence drop had already been revealed [24].…”

Section: Spectrophotometric and Fluorimetric Investigation Of The Int...mentioning

confidence: 99%

“…Figures 4, 5, S12 and S13 show the data matrix (upper panel: colored map, ∆A vs. λ and τ, on x-axis and y-axis, respectively), representative spectra and kinetics (central panel), and Evolution Associated Spectra (EAS) of the transients describing the excited-state dynamics with their characteristic lifetimes (lower panel) [40]. Table 3 compiles the results of the global fitting analysis carried out by GloTarAn software [41] together with the excited-state properties of the free molecules in water [36], reported for comparison purposes.…”

Section: Femtosecond Transient Absorption Spectroscopy Of Complexes W...mentioning

confidence: 99%

“…Within this broader context, we have recently synthesized a series of six quadrupolar styryl azinium dyes, having a more extended A + -π-D-π-A + structure (Scheme 1). These bicationic fluorophores were thoroughly characterized as for their photobehavior in solvents of different polarity and their nonlinear optical response [36]. Interestingly, the net positive charges in these double-arm push-pull molecules provided enhanced ICT character, resulting in notable two-photon absorption (TPA) cross-sections, and improved water solubility.…”

Section: Introductionmentioning

confidence: 99%

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Amphiphilicity-Controlled Localization of Red Emitting Bicationic Fluorophores in Tumor Cells Acting as Bio-Probes and Anticancer Drugs

et al. 2022

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Small organic molecules arouse lively interest for their plethora of possible biological applications, such as anticancer therapy, for their ability to interact with nucleic acids, or bioimaging, thanks to their fluorescence emission. Here, a panchromatic series of styryl-azinium bicationic dyes, which have already proved to exhibit high water-solubility and significant red fluorescence in water, were investigated through spectrofluorimetric titrations to assess the extent of their association constants with DNA and RNA. Femtosecond-resolved transient absorption spectroscopy was also employed to characterize the changes in the photophysical properties of these fluorophores upon interaction with their biological targets. Finally, in vitro experiments conducted on tumor cell lines revealed that some of the bicationic fluorophores had a peculiar localization within cell nuclei exerting important antiproliferative effects, others were instead found to localize in the cytoplasm without leading to cell death, being useful to mark specific organelles in light of live cell bioimaging. Interestingly, this molecule-dependent behavior matched the different amphiphilicity featured by these bioactive compounds, which are thus expected to be caught in a tug-of-war between lipophilicity, ensured by the presence of aromatic rings and needed to pass cell membranes, and hydrophilicity, granted by charged groups and necessary for stability in aqueous media.

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Section: Spectrophotometric and Fluorimetric Investigation Of The Int...mentioning

confidence: 97%

Section: Spectrophotometric and Fluorimetric Investigation Of The Int...mentioning

confidence: 99%

Section: Spectrophotometric and Fluorimetric Investigation Of The Int...mentioning

confidence: 99%

Section: Femtosecond Transient Absorption Spectroscopy Of Complexes W...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Amphiphilicity-Controlled Localization of Red Emitting Bicationic Fluorophores in Tumor Cells Acting as Bio-Probes and Anticancer Drugs

et al. 2022

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Perfect Polar Alignment of Parallel Beloamphiphile Layers: Improved Structural Design Bias Realized in Ferroelectric Crystals of the Novel “Methoxyphenyl Series of Acetophenone Azines”

Bhoday,

Knotts,

Glaser

2024

Chemistry A European J

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An improved design is described for ferroelectric crystals and implemented with the “methoxyphenyl series” of acetophenone azines, (MeO−Ph, Y)‐azines with Y=F (1), Cl (2), Br (3), or I (4). The crystal structures of these azines exhibit polar stacking of parallel beloamphiphile monolayers (PBAMs). Azines 1, 3, and 4 form true racemates whereas chloroazine 2 crystallizes as a kryptoracemate. Azines 1–4 are helical because of the N−N bond conformation. In true racemates the molecules of opposite helicity (M and P) are enantiomers A(M) and A*(P) while in kryptoracemates they are diastereomers A(M) and B*(P). The stacking mode of PBAMs is influenced by halogen bonding, with 2–4 showcasing a kink due to directional interlayer halogen bonding, whereas fluoroazine 1 demonstrates ideal polar stacking by avoiding it. Notably, (MeO−Ph, Y)‐azines display a stronger bias for dipole parallel alignment, attributed to the linearity of the biphenyl moiety as compared to the phenoxy series of (PhO, Y)‐azines with their non‐linear Ph−O−Ph moiety. The crystals of 1–4 all feature planar biphenyls and this synthon facilitates their crystallization through potent triple T‐contacts and enhances their nonlinear optical (NLO) performance by increasing conjugation length and affecting favorable chromophore conformations in the solids.

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Dual‐State Emission and Two‐Photon Absorption Tuned by Benzonitrile Substitution in 2,3,4,5‐Tetraphenyl‐1H‐Pyrrole

et al. 2023

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A series of nine 2,3,4,5‐tetraphenyl pyrrole derivatives presenting benzonitrile substitution at different positions was designed and synthesized for this work. Their structure–emission property relationships were investigated in depth through a joint advanced experimental and computational effort. Our ultrafast and non‐linear spectroscopic results showed more efficient intramolecular charge transfer and enhanced two‐photon absorption cross sections when the benzonitrile substitution is at position 3 of the central pyrrole. On the other hand, an intriguing dual‐state emission behaviour was found to be activated by substitution at position 2, with exceptionally large photoluminescence quantum yields exhibited both in solution and in the solid state. Indeed, the quantum chemical simulations revealed for the derivatives functionalized at position 2 that the distorted geometry of the benzonitrile substituent with respect to the phenyl ring prevents emission quenching in the aggregate species by π‐π stacking interactions. Our findings shed new light on optimized design strategies of highly emitting materials for efficient optoelectronic devices.

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Nonlinear optical properties of a new panchromatic series of water-soluble bicationic push-pull fluorophores

Cited by 19 publications

References 88 publications

Amphiphilicity-Controlled Localization of Red Emitting Bicationic Fluorophores in Tumor Cells Acting as Bio-Probes and Anticancer Drugs

Amphiphilicity-Controlled Localization of Red Emitting Bicationic Fluorophores in Tumor Cells Acting as Bio-Probes and Anticancer Drugs

Perfect Polar Alignment of Parallel Beloamphiphile Layers: Improved Structural Design Bias Realized in Ferroelectric Crystals of the Novel “Methoxyphenyl Series of Acetophenone Azines”

Dual‐State Emission and Two‐Photon Absorption Tuned by Benzonitrile Substitution in 2,3,4,5‐Tetraphenyl‐1H‐Pyrrole

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