The voltammetry of triarylmethane dyes in acetonitrile

Němcová, I.; Němec, Ivan

doi:10.1016/0368-1874(71)87035-1

Cited by 17 publications

(6 citation statements)

References 22 publications

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“…The derived potentials are summarized in Fig. 8 for triangulenium 1, 35 3, 30 4, 30 5, 30 11 6 and DMQA + 6. 36 Clearly, the more the nitrogen atoms present in the triangulene core or as substituents, the easier it is to oxidize the corresponding carbenium ions.…”

Section: Electrochemistrymentioning

confidence: 99%

Cationic triangulenes and helicenes: synthesis, chemical stability, optical properties and extended applications of these unusual dyes

2014

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Cationic triangulenes and helicenes are highly stable carbocations with planar and helical conformations respectively. These moieties are effective dyes with original absorption and emission properties. Over the last decade, they have received greater attention and are considered as valuable tools for the development of innovative applications. In this review, the synthesis of these unique compounds is presented together with their core chemical and physical properties. Representative applications spanning from surface sciences to biology and chemistry are presented.

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Section: Electrochemistrymentioning

confidence: 99%

Cationic triangulenes and helicenes: synthesis, chemical stability, optical properties and extended applications of these unusual dyes

2014

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“…The half-wave reduction potential of TOTA ϩ has been reported as E ½ red = Ϫ0.385 V versus SCE in acetonitrile. 14 For PX ϩ , E ½ red = Ϫ0.25 V, and for X ϩ , E ½ red = Ϫ0.25 V versus SCE (converted from ferrocenium/ ferrocene reference; the numeric identity is accidental) 64 However, these values refer to solutions in sulfolane/3methylsulfolane(5%). The driving force of the reaction also depends on the excitation energy E(S1) of the acceptor (Rehm-Weller, eqn.…”

Section: Fluorescence Quenching By Nucleophilic Attack and Electron T...mentioning

confidence: 99%

“…Since publication of the synthesis 11 of TOTA ϩ only little attention has been given to its one-electron reduction. 14 Properties of the excited states of TOTA ϩ have not been reported except for a conference proceeding, 15 a PhD thesis, 16 and a recent short communication by Dileesh and Gopidas. 17 our initial investigations 15, 16 of the physical and chemical properties of the S 0 , S 1 , and T 1 states of TOTA ϩ are presented.…”

Section: Introductionmentioning

confidence: 99%

Photophysics of trioxatriangulenium ion. Electrophilic reactivity in the ground state and excited singlet state

Reynisson

Wilbrandt

Brinck

et al. 2002

Photochem Photobiol Sci

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Trioxatriangulenium (TOTA+. 4,8,12-trioxa-4,8,12,12c-tetrahydro-dibenzo[cd,mn]-pyrenylium) is a closed shell carbenium ion, which is stable in non-nucleophilic polar solvents at ambient temperatures In alcohols, small quantities of the leuco ether are formed in a reversible reaction. The physical and chemical properties of the excited singlet state of the trioxatriangulenium (TOTA+) carbenium ion are investigated by experimental and computational means The degeneracy of the lowest excited states is counteracted by Jahn-Teller-type distortion, which leads to vibronic broadening of the long wavelength absorption band. A strong fluorescence is observed at 520 nm (tau(fl) = 14.6 ns, phi(fl) = 0.12 in deaerated acetonitrile). The fluorescence is quenched by 10 aromatic electron donors predominantly via a dynamic charge transfer mechanism, but ground state complexation is shown to contribute in varying degrees Quenching is also observed in the presence of halide ions Quenching rate constants are derived from lifetime measurements while charge transfer (CT) complex formation constants follow from the steady-state Stern-Volmer plots. CT-complex formation with three discogenic triphenylenes is studied separately. Phosphorescence spectra, triplet lifetimes. and triplet-triplet absorption spectra are provided. In the discussion, TOTA+ is compared to the unsubstituted xanthenium ion and its 9-phenyl derivative with respect to the excited state properties.

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“…It seemed that TOTA + is an ideal compound for examination of the structural, electronic, and chemical effects of an intercalator having a relatively low-energy unfilled orbital. Trioxatriangulenium carbocation (TOTA + , Figure ) is a stable, planar 9 compound with a relatively low-energy LUMO. , Optical excitation of TOTA + with visible light in aqueous solution forms excited states capable of the one-electron oxidation of guanosine or adenosine 1 Chemical structure of TOTA + ; the numbers are used to identify atomic interactions revealed in the X-ray crystal structure. …”

Section: Introductionmentioning

confidence: 99%

Intercalation of Trioxatriangulenium Ion in DNA: Binding, Electron Transfer, X-ray Crystallography, and Electronic Structure

et al. 2003

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Trioxatriangulenium ion (TOTA(+)) is a flat, somewhat hydrophobic compound that has a low-energy unoccupied molecular orbital. It binds to duplex DNA by intercalation with a preference for G-C base pairs. Irradiation of intercalated TOTA(+) causes charge (radical cation) injection that results in strand cleavage (after piperidine treatment) primarily at GG steps. The X-ray crystal structure of TOTA(+) intercalated in the hexameric duplex d[CGATCG](2) described here reveals that intercalation of TOTA(+) results in an unusually large extension of the helical rise of the DNA and that the orientation of TOTA(+) is sensitive to hydrogen-bonding interactions with backbone atoms of the DNA. Electronic structure calculations reveal no meaningful charge transfer from DNA to TOTA(+) because the lowest unoccupied molecular orbital of TOTA(+), (LUMO)(T), falls in the gap between the highest occupied molecular orbital, (HOMO)(D), and the (LUMO)(D) of the DNA bases. These calculations reveal the importance of backbone, water, and counterion interactions, which shift the energy levels of the bases and the intercalated TOTA(+) orbitals significantly. The calculations also show that the inserted TOTA(+) strongly polarizes the intercalation cavity where a sheet of excess electron density surrounds the TOTA(+).

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The voltammetry of triarylmethane dyes in acetonitrile

Cited by 17 publications

References 22 publications

Cationic triangulenes and helicenes: synthesis, chemical stability, optical properties and extended applications of these unusual dyes

Cationic triangulenes and helicenes: synthesis, chemical stability, optical properties and extended applications of these unusual dyes

Photophysics of trioxatriangulenium ion. Electrophilic reactivity in the ground state and excited singlet state

Intercalation of Trioxatriangulenium Ion in DNA: Binding, Electron Transfer, X-ray Crystallography, and Electronic Structure

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