Zum äußeren Schweratom-Effekt der Phosphoreszenz in nicht-fluoreszierenden aromatischen Verbindungen / The External Heavy-Atom-Effect of Phosphorescence in Non-fluorescing Aromatic Compounds

1973 ◽  
Vol 28 (11) ◽  
pp. 1869-1870
Author(s):  
M. Zander
Keyword(s):  
Triplet State ◽  
Aromatic Compounds ◽  
Heavy Atom ◽  
Quantum Yields ◽  
Naphthalene Derivatives ◽  
Heavy Atom Effect ◽  
Atom Effect

Phosphorescence quantum yields of six non-fluorescing naphthalene derivatives have been measured in ethanol and ethanol-ethylbromide 1:1 at 77 °K. The observed enhancement of phosphorescence yield of four of these in the heavy atom solvent is explained with the assumption that the rate of the phosphorescence transition is increased relatively to the radiationless desactivation of the triplet state.

scholarly journals Phosphoreszenzeigensch aften von Methyl-, Chlor- und Brom-Derivaten des [2.2] Paracyclophans

1987 ◽  
Vol 42 (9) ◽  
pp. 1041-1042 ◽  
Author(s):  
H. Hopf ◽  
E. Hermann
Keyword(s):  
Triplet State ◽  
Fluorescence Spectra ◽  
Heavy Atom ◽  
The Other ◽  
Quantum Yields ◽  
Heavy Atom Effect ◽  
Chloro Derivatives ◽  
Derivatives Of ◽  
Atom Effect

Phosphorescence and fluorescence spectra, quantum yields of phosphorescence and fluorescence as well as phosphorescence lifetimes have been measured of six methyl-, chloro- and bromo-derivatives of [2.2] paracyclophane in ethanol at 77 K. While the chloro-derivatives as well as dibromo-paracyclophane exhibit a normal internal heavy-atom effect behaviour the momobromo-compound shows anomalies. These possibly indicate that in the monobromo-compound an additional pathway of the radiationless deactivation of the lowest triplet state is effective which does not occur with the other compounds.

Löschung der Perylen-Fluoreszenz durch Ag+ -Ionen / Quenching of the Perylene Fluorescence by Ag+-Ions

1983 ◽  
Vol 38 (6) ◽  
pp. 698-700 ◽  
Author(s):  
H. Dreeskamp ◽  
A. Läufer ◽  
M. Zander
Keyword(s):  
Triplet State ◽  
Dynamic Process ◽  
Aromatic Compounds ◽  
Heavy Atom ◽  
Silver Ions ◽  
Intersystem Crossing ◽  
Fluid Solution ◽  
Long Wavelength ◽  
Wavelength Emission ◽  
Atom Effect

The fluorescence of perylene in fluid solution (λ0.0 = 440 nm) is quenched by silver ions in a dynamic process according to a Stern-Volmer kinetics (kq = 2 · 109 [1 • mol-1 · sec-1], in ethanol at 295 K). Simultaneously an unstructured long-wavelength emission (λmax ≈ 470 nm) appears which we assign to a perylene/Ag+ exciplex. A similar emission is observed when other polvcyclic aromatic compounds (PAC) are used, whose fluorescence as in the case of perylene is not easily quenched in an external heavy atom effect by iodopropane (kq ≦ 106). In these cases the excited PAC/Ag+ complex is long-lived enough to emit fluorescence since the intersystem crossing to the triplet system is slow due to the absence of an energetically favorable accepting triplet state

An exceptionally long-lived triplet state of red light-absorbing compact phenothiazine-styrylBodipy electron donor/acceptor dyads: a better alternative to the heavy atom-effect?

2020 ◽  
Vol 56 (11) ◽  
pp. 1721-1724 ◽  
Author(s):  
Yuqi Hou ◽  
Qingyun Liu ◽  
Jianzhang Zhao
Keyword(s):  
Charge Transfer ◽  
Triplet State ◽  
Electron Donor ◽  
Heavy Atom ◽  
Red Light ◽  
Intersystem Crossing ◽  
Spin Orbital ◽  
Heavy Atom Effect ◽  
Donor Acceptor ◽  
Atom Effect

Heavy atom-free dyads showing a red light-absorbing and exceptionally long-lived triplet state based on a spin–orbital charge transfer intersystem crossing mechanism.

Notizen: Zur Lumineszenz von aromatischen Verbindungen mit Schweratom-Substituenten in unterschiedlichen Bindungssituationen / On the Luminescence of Aromatic Compounds with Heavy Atom Substituents in Different Bonding Situations.

1979 ◽  
Vol 34 (7) ◽  
pp. 909-910 ◽  
Author(s):  
G.-P. Blümer ◽  
M. Zander
Keyword(s):  
Electron Density ◽  
Aromatic Compounds ◽  
Heavy Atom ◽  
Electronic System ◽  
Chlorine Atoms ◽  
Heavy Atom Effect ◽  
Inductive Effects ◽  
Atom Effect

Compounds like III(4,9,10,11,12,13,13-Heptachloro-8b,9,12,12a-tetrahydro-9,12-methano-benzo[e]pyrene) are ex­amples for systems with heavy atom substituents in two different bonding situations. The halogen directly connected with the 7-electronic system causes an internal heavy atom effect whilst the halogens isolated from the .7-system by aliphatic carbons produce a “quasi external” heavy atom effect. The observation that the internal heavy atom effect in III is weaker than in halo phenanthrenes is explained with the lower electron density in the phenanthrene unit of III compared to phenanthrene. this lower electron density being a result of field and inductive effects of the peripherically arranged chlorine atoms.

scholarly journals Heavy-atom effect on optically excited triplet state kinetics

PLoS ONE ◽  
2017 ◽  
Vol 12 (11) ◽  
pp. e0184239
Author(s):  
Christian Hintze ◽  
Tobias O. Morgen ◽  
Malte Drescher
Keyword(s):  
Triplet State ◽  
Heavy Atom ◽  
Excited Triplet State ◽  
Excited Triplet ◽  
Heavy Atom Effect ◽  
Atom Effect

Electrochemical and photophysical characterization of non-peripherally-octaalkyl substituted dichlorotin(IV) phthalocyanine and tetrabenzotriazaporphyrin compounds

2007 ◽  
Vol 11 (10) ◽  
pp. 761-770 ◽  
Author(s):  
Samson Khene ◽  
Andrew N. Cammidge ◽  
Michael J. Cook ◽  
Tebello Nyokong
Keyword(s):  
Cyclic Voltammetry ◽  
Quantum Yield ◽  
Triplet State ◽  
Electrochemical Behavior ◽  
Heavy Atom ◽  
Quantum Yields ◽  
Redox Processes ◽  
Central Metal ◽  
Atom Effect

Three non-peripherally substituted tin(IV) macrocylic compounds, octahexylphthalocyaninato dichlorotin(IV) (3a), octahexyltetrabenzo-5,10,15- triazaporphyrinato dichlorotin(IV) (3b) and octadecylphthalocyaninato dichlorotin(IV) (3c) were synthesized and their photophysical and electrochemical behavior studied. Complex 3b, containing a CH group in place of one of the aza nitrogen atoms of the phthalocyanine core, shows a split Q-band due to its lower symmetry. The triplet state quantum yields were found to be lower than would be expected on the basis of the heavy atom effect of tin as the central metal for phthalocyanine derivatives (3a and 3c). In contrast, 3b shows a triplet quantum yield Φ T = 0.78. The triplet state lifetimes were solvent dependent, and were higher in tetrahydrofuran than in toluene. Cyclic voltammetry and spectroelectrochemistry of the complexes revealed only ring-based redox processes.

Photophysical and theoretical studies of peripherally halogenated octaphenoxyphthalocyanines

RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58854-58864 ◽  
Author(s):  
Saad Makhseed ◽  
Basma Ghazal ◽  
Amr Mohamed Abdelmoniem ◽  
Veronika Novakova ◽  
Petr Zimcik
Keyword(s):  
Singlet Oxygen ◽  
Electronic Structures ◽  
Heavy Atom ◽  
Experimental Results ◽  
Quantum Yields ◽  
Theoretical Studies ◽  
Computational Studies ◽  
Two Dimensional ◽  
Heavy Atom Effect ◽  
Atom Effect

Computational studies validated the experimental results and revealing details about the electronic structures of novel halogenated phthalocyanines. Fluorescence and singlet oxygen quantum yields analysis revealed two-dimensional heavy atom effect.

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