Fluorescence of bromoperylenes and the requirements of heavy-atom quenching

Dreeskamp, H.; Koch, E.; Zander, M.

doi:10.1016/0009-2614(75)85014-7

Cited by 44 publications

(27 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…42–44 For instance, at 77 K, 10-phenylphenoxazine was reported to access a 3 PC* with a lifetime up to 2.3 s and a phosphorescence quantum yield of 94%. 47 Under otherwise similar reaction conditions, the visible light absorbing PC 2 produced polymer product with Đ as low as 1.13 and quantitative I *, as compared to perylene which synthesized polymers with Đ as low as 1.39, and I * < 50% for a variety of experimental conditions.…”

Section: Resultsmentioning

confidence: 99%

Impact of Light Intensity on Control in Photoinduced Organocatalyzed Atom Transfer Radical Polymerization

et al. 2017

View full text Add to dashboard Cite

Organic photoredox catalysts have been shown to operate organocatalyzed atom transfer radical polymerizations (O-ATRP) using visible light as the driving force. In this work, the effect of light intensity from white LEDs was evaluated as an influential factor in control over the polymerization and the production of well-defined polymers. We posit the irradiation conditions control the concentrations of various catalyst states necessary to mediate a controlled radical polymerization. Systematic dimming of white LEDs allowed for consideration of the role of light intensity on the polymerization performance. The general effects of decreased irradiation intensity in photoinduced O-ATRP were investigated through comparing two different organic photoredox catalysts: perylene and an 3,7-di(4-biphenyl) 1-naphthalene-10-phenoxazine. Previous computational efforts have investigated catalyst photophysical and electrochemical characteristics, but the broad and complex effects of varied irradiation intensity as an experimental variable on the mechanism of O-ATRP have not been explored. This work revealed that perylene requires more stringent irradiation conditions to achieve controlled polymer molecular weight growth and produce polymers with dispersities <1.50. In contrast, the 3,7-di(4-biphenyl) 1-naphthalene-10-phenoxazine is more robust, achieving linear polymer molecular weight growth under relative irradiation intensity as low as 25%, to produce polymers with dispersities <1.50. This finding is significant, as the discovery of highly robust catalysts is necessary to allow for the adoption of successful O-ATRP in a wide scope of conditions, including those which necessitate low light intensity irradiation.

show abstract

Section: Resultsmentioning

confidence: 99%

Impact of Light Intensity on Control in Photoinduced Organocatalyzed Atom Transfer Radical Polymerization

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The weak luminescence of 20 may be due to heavy atom quenching by bromine. 29 The increased luminescence of 21 could occur in a manner similar to that of the structural homolog 18 , i.e. , through DNA-templated dimerization.…”

Section: Resultsmentioning

confidence: 99%

Luminescent Properties of Ruthenium(II) Complexes with Sterically Expansive Ligands Bound to DNA Defects

et al. 2012

View full text Add to dashboard Cite

A new family of ruthenium(II) complexes with sterically expansive ligands for targeting DNA defects was prepared, and their luminescent responses to base pair mismatches and/or abasic sites were investigated. The design of the complexes sought to combine the mismatch specificity of sterically expansive metalloinsertors, such as [Rh(bpy)2(chrysi)]3+ (chrysi = chrysene-5,6-quinone diimine), and the light switch behavior of [Ru(bpy)2(dppz)]2+ (dppz = dipyrido[3,2-a:2′,3′-c]phenazine). In one approach, complexes bearing analogues of chrysi incorporating hydrogen-bonding functionality similar to dppz were synthesized. While the complexes show luminescence only at low temperatures (77 K), competition experiments with [Ru(bpy)2(dppz)]2+ at ambient temperatures reveal that the chrysi derivatives preferentially bind DNA mismatches. In another approach, various substituents were introduced onto the dppz ligand to increase its steric bulk for mismatch binding while maintaining planarity. Steady state luminescence and luminescence lifetime measurements reveal that these dppz derivative complexes behave as DNA “light switches,” but that the selectivity in binding and in luminescence with mismatched/abasic versus well-matched DNA is not high. In all cases, the luminescence depends sensitively upon structural perturbations to the dppz ligand.

show abstract

“…In tetrahydrofurane, at room temperature, we obtained t f =4.5 ns; the dependence of the fluorescence lifetime on temperature is usually not significant [13]. Assuming that the tf value for Mg-TAP in Xe matrix is not much different from that in the solution (as observed for aromatic hydrocarbons [17,18]), the expected lifetimelimited zero-phonon linewidth should be ~35 MHz, which is not far from the low frequency histogram cut-off, at 20-30 MHz.…”

Section: Single Molecule Spectroscopy Of Mg Tetraazaporphyrin In Solimentioning

confidence: 98%

Single Molecule Spectroscopy of Mg Tetra-azaporphyrin in Solid Xenon

et al. 2001

View full text Add to dashboard Cite

We report initial results on the spectroscopy of single Mgtetra-azaporphyrin molecules in solid xenon. Samples were prepared following the conventional matrix-isolation procedure. Single molecules, detected by fluorescence microscopy, gave remarkably stable signals. Their fluorescence excitation spectra revealed sharp zero-phonon lines, with most represented linewidths around 50 MHz. This is the first study of single molecules of a tetrapyrrolic compound.

show abstract

Fluorescence of bromoperylenes and the requirements of heavy-atom quenching

Cited by 44 publications

References 12 publications

Impact of Light Intensity on Control in Photoinduced Organocatalyzed Atom Transfer Radical Polymerization

Impact of Light Intensity on Control in Photoinduced Organocatalyzed Atom Transfer Radical Polymerization

Luminescent Properties of Ruthenium(II) Complexes with Sterically Expansive Ligands Bound to DNA Defects

Single Molecule Spectroscopy of Mg Tetra-azaporphyrin in Solid Xenon

Contact Info

Product

Resources

About