The effect of heavy-atom solvents on the photooxidation of anthracene

1984 ◽  
Vol 62 (10) ◽  
pp. 2047-2053 ◽  
Author(s):  
Naoki Toshima ◽  
Toshihiko Sugano ◽  
Hidefumi Hirai
Keyword(s):  
Oxidation Product ◽  
Coupling Parameter ◽  
Heavy Atom ◽  
Solvent Molecule ◽  
High Yield ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Radical Intermediate ◽  
Effect Of Heavy Atom ◽  
Atom Effect

Photoirradiation of anthracene in benzene in the presence of oxygen gave predominantly a photodimer of anthracene, and very little oxidation product. Similar irradiation of anthracene in bromobenzene, however, produced 9,10-anthraquinone in high yield. The yield of anthraquinone increased in the presence of a heavy-atom solvent such as bromobenzene, p-dibromobenzene, 1,3,5-tribromobenzene, 1-bromopropane, and dibromomethane in proportion to the sum of squares of the spin–orbit coupling parameter ζ of the solvent molecule. This relationship indicates an external heavy-atom effect on the photooxidation of anthracene. The mechanistic investigations suggest the involvement of singlet oxygen, anthracene peroxide, and a radical intermediate in the formation of anthraquinone.

Internal heavy-atom effect on spin–orbit and vibronic–spin–orbit coupling: nπ∗ phosphorescence of 9,10-anthraquinone haloderivatives

1999 ◽  
Vol 248 (2-3) ◽  
pp. 233-246 ◽  
Author(s):  
N.V. Korol'kova ◽  
V.G. Klimenko ◽  
T.A. Kir'yanova ◽  
S.A. Serov ◽  
E.A. Gastilovich
Keyword(s):  
Heavy Atom ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Heavy Atom Effect ◽  
Atom Effect

Untersuchung zur externen Spin-Bahn-Kopplung bei aromatischen Molekülen / External Spin-Orbit-Coupling in Aromatic Molecules

1976 ◽  
Vol 31 (7) ◽  
pp. 748-753
Author(s):  
J. Friedrich ◽  
G. Weinzierl ◽  
F. Dörr
Keyword(s):  
Nuclear Charge ◽  
Heavy Atom ◽  
Orbit Coupling ◽  
Coupling Mechanism ◽  
Intermolecular Distance ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Overlap Integrals ◽  
Aromatic Molecules ◽  
Atom Effect

Abstract The influence of ethylhalogenes on the polarization of the phosphorescence of naphthalene was studied by means of the photoselection technique. It is shown that with increasing concentration and with increasing nuclear charge of the heavy atom the phosphorescence of naphthalene becomes increasingly depolarized. The influence of the external heavy atom on the Tx- and Tz- substate is stronger than on the Ty-substate. From the concentration dependence of the depolarizatign conclusions concerning the mechanism of the external spin-orbit-coupling are drawn. The dirept spin-orbit-coupling mechanism is ruled out. In the model discussed the variation of the external heavy atom effect with the intermolecular distance is related to overlap integrals.

On the Phosphorescence of Benzologues of Furan , Thiophene , Selenophene , and Tellurophene . A Systematic Study of the Intra -annular Internal Heavy-atom Effect

1989 ◽  
Vol 44 (3) ◽  
pp. 205-209 ◽  
Author(s):  
M. Zander ◽  
G. Kirsch
Keyword(s):  
Systematic Study ◽  
Linear Correlation ◽  
Heavy Atom ◽  
Vibrational Structure ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupling Constant ◽  
Atom Effect ◽  
Internal Perturbation ◽  
Phosphorescence Spectra

Phosphorescence in ethanol and n-pentane at 77 K of the benzologues 1-8 of furan, thiophene, selenophene and tellurophene has been investigated. The rate constants of both the radiative (kPT) and non-radiative (kGT) deactivation of the lowest triplet state correlate linearly with where ck denotes the Hückel AO coefficients in the HOMO of the carbon atoms bound to the hetero-atom and ζ is the spin-orbit coupling constant of the hetero-atom present. - The linear correlation observed between kPT and kGT is an example for the Orlandi-Siebrand rule. - The influence of an external heavy-atom perturber (methyl iodide) on phosphorescence lifetimes and the vibrational structure of phosphorescence spectra is the more efficient the less efficient is the internal perturbation caused by the intra-annular heavy-atom.

Inverse Heavy-Atom Effect in Near Infrared Photoluminescent Gold Nanoclusters

Nanoscale ◽  
2021 ◽  
Author(s):  
Goutam Pramanik ◽  
Klaudia Kvakova ◽  
Muhammed Arshad Thottappali ◽  
David Rais ◽  
Jiri Pfleger ◽  
...  
Keyword(s):  
Near Infrared ◽  
Heavy Atom ◽  
Gold Nanoclusters ◽  
Fluorescence Decay ◽  
Orbit Coupling ◽  
Heavy Elements ◽  
Intersystem Crossing ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Atom Effect

Fluorophores functionalized with heavy elements show enhanced intersystem crossing due to increased spin–orbit coupling, which in turn shortens the fluorescence decay lifetime (τPL). This phenomenon is known as the heavy-atom...

The Intra-annular Internal Heavy-atom Effect on the Fluorescence and Phosphorescence Properties of Oxygen, Sulphur or Selenium Containing Heterocyclic Systems Related to Dibenzo [b,n] perylene

1989 ◽  
Vol 44 (11) ◽  
pp. 1116-1118 ◽  
Author(s):  
M. Zander
Keyword(s):  
Fluorescence Quenching ◽  
Heavy Atom ◽  
Quantum Yields ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupling Constant ◽  
Heavy Atom Effect ◽  
Fluorescence Quantum Yields ◽  
Atom Effect ◽  
Fluorescence And Phosphorescence

Fluorescence and phosphorescence properties of dibenzo [2,3:10,11] perylo [1,12-bcd] furan (1), dibenzo [2,3:10,11] perylo [1,12-bcd] thiophene (2), and dibenzo [2,3:10,11 ] perylo [1,12-bcd] selenophene (3) have been studied. Fluorescence quantum yields as well as phosphorescence lifetimes correlate linearly with where ck are the Hückel AO coefficients in the HOMO of the parent carbocyclic system dibenzo [b, n] perylene (4) on carbon centres k to which the hetero-atom is bound, and ζ is the spin-orbit coupling constant of the heavy-atom present. The half-value concentration of fluorescence quenching (quencher: methyl iodide) of 1 - 3 increases with increasing strength of the internal heavy-atom effect present

scholarly journals Photophysical Heavy-Atom Effect in Iodinated Metallocorroles: Spin–Orbit Coupling and Density of States

2018 ◽  
Vol 122 (37) ◽  
pp. 7256-7266 ◽  
Author(s):  
Enrico Pomarico ◽  
Petr Pospíšil ◽  
Marine E. F. Bouduban ◽  
Jenya Vestfrid ◽  
Zeev Gross ◽  
...  
Keyword(s):  
Density Of States ◽  
Heavy Atom ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Heavy Atom Effect ◽  
Atom Effect

EPR Parameters and Local Atom-position Parameters for Co2+ Ions in CdS and CdSe Semiconductors

2004 ◽  
Vol 59 (11) ◽  
pp. 783-786 ◽  
Author(s):  
Wen-Chen Zheng ◽  
Xiao-Xuan Wu ◽  
Yang Mei ◽  
Jian Zi
Keyword(s):  
Coupling Parameter ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Cluster Approach ◽  
Zero Field Splitting ◽  
Trigonal Symmetry ◽  
Epr Parameters ◽  
Impurity Centers ◽  
Atom Position

The EPR parameters (zero-field splitting D and g factors gII, g⊥) of Co2+ ions in CdS and CdSe semiconductors are calculated from the high-order perturbation formulas based on the cluster approach for a 3d7 ion in trigonal symmetry. These formulas include the contribution to the EPR parameters from both the spin-orbit coupling parameter of the 3d7 ion and that of the ligand. From the calculations, the local atom-position parameters u (which are different from the corresponding values in the host crystals) for the Co2+ impurity centers in both semiconductors are estimated. The results are discussed

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