Journal ArticleDOI
Kinetics of Fluorescence Quenching by Electron and H‐Atom Transfer
Dieter Rehm,Albert Weller +1 more
TLDR
In this article, the rate constants of 60 typical electron donor-acceptor systems have been measured in de-oxygenated acetonitrile and are shown to be correlated with the free enthalpy change, ΔG23, involved in the actual electron transfer process.Abstract:
Fluorescence quenching rate constants, kq, ranging from 106 to 2 × 1010 M−1 sec−1, of more than 60 typical electron donor-acceptor systems have been measured in de-oxygenated acetonitrile and are shown to be correlated with the free enthalpy change, ΔG23, involved in the actual electron transfer process
in the encounter complex and varying between + 5 and −60 kcal/mole. The correlation which is based on the mechanism of adiabatic outer-sphere electron transfer requires ΔG≠23, the activation free enthalpy of this process to be a monotonous function of ΔG23 and allows the calculation of rate constants of electron transfer quenching from spectroscopic and electrochemical data.
A detailed study of some systems where the calculated quenching constants differ from the experimental ones by several orders of magnitude revealed that the quenching mechanism operative in these cases was hydrogen-atom rather than electron transfer.
The conditions under which these different mechanisms apply and their consequences are discussed.read more
Citations
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Journal ArticleDOI
A benzophenone-naphthalimide derivative as versatile photoinitiator of polymerization under near UV and visible lights
Jing Zhang,Nicolas Zivic,Frédéric Dumur,Pu Xiao,Bernadette Graff,Didier Gigmes,Jean Pierre Fouassier,Jacques Lalevée +7 more
TL;DR: A benzophenone-naphthalimide derivative (BPND) bearing tertiary amine groups has been developed as a high-performance photoinitiator in combination with 2,4,6-tris(trichloromethyl)-1,3,5-triazine or an iodonium salt for both the tree radical polymerization (FRP) of acrylates and the cationic polymeric polymerization (CP) of epoxides upon exposure to near UV and visible LEDs (385-470 nm).
Journal ArticleDOI
A Two-length Scale Turbulence Model for Single-phase Multi-fluid Mixing
TL;DR: In this article, a two-length scale, second moment turbulence model (Reynolds averaged Navier-Stokes, RANS) is proposed to capture a wide variety of single-phase flows, spanning from incompressible flows with single fluids and mixtures of different density fluids (variable density flows) to flows over shock waves.
Journal ArticleDOI
C60 as a Photocatalyst of Electron-Transfer Processes: Reactions of Triplet C60 with Chloranil, Perylene, and Tritolylamine Studied by Flash Photolysis and FT-EPR
TL;DR: In this paper, the formation rate and yield of CA- are much increased by addition of perylene (Pe) or tritolylamine (TTA) via the fast reactions 3C60 + Pe → C60 + 3Pe, followed by 3Pe + CA → Pe+ + CA-, or 3C 60 + TTA → C 60-+ TTA+, followed by C60- + C60+ CA- + CA-
Journal ArticleDOI
Synthesis and Photophysical Properties of Donor- and Acceptor-Substituted 1,7-Bis(arylalkynyl)perylene-3,4:9,10-bis(dicarboximide)s
Zesheng An,Susan A. Odom,Richard F. Kelley,Chun Huang,Xuan Zhang,Stephen Barlow,Lazaro A. Padilha,Jie Fu,Scott Webster,David J. Hagan,Eric W. Van Stryland,Michael R. Wasielewski,Seth R. Marder +12 more
TL;DR: The two-photon absorption properties of three bis(arylethynyl)-substituted derivatives were investigated, along with those of 1,7-di(pyrrolidin-1-yl)-N,N'-bis[2,6-diisopropylphenyl]perylene-3,4:9,10-bis(dicarboximide).
Journal ArticleDOI
Substituted 1,5-Diphenyl-3-benzothiazol-2-yl-Δ2-pyrazolines: Synthesis, X-ray Structure, Photophysics, and Cation Complexation Properties
TL;DR: In this paper, the spectroscopic properties of 1-phenyl-3-benzothiazol-2-yl-5-(4-R)-phenyl)-Δ2-pyrazolines are strongly dependent on both the electronic nature of the substituent and solvent polarity.
References
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Journal ArticleDOI
On the Theory of Oxidation‐Reduction Reactions Involving Electron Transfer. I
TL;DR: In this paper, a mechanism for electron transfer reactions is described, in which there is very little spatial overlap of the electronic orbitals of the two reacting molecules in the activated complex, and a quantitative theory of the rates of oxidation reduction reactions involving electron transfer in solution is presented.
Journal ArticleDOI
Chemical and Electrochemical Electron-Transfer Theory
TL;DR: In this article, a review of electron transfer reactions is presented, focusing on the absence of bond rupture in the reaction step, which is a unique feature of purely electron-transfer reactions.
Journal ArticleDOI
Polarographic Oxidation Potentials of Aromatic Compounds
E. S. Pysh,N. C. Yang +1 more
TL;DR: In this article, the oxidation half-wave potentials of fifty-three organic compounds were determined in acetonitrile at a rotating Pt electrode, and these values were correlated with ionization potentials, with interaction energies of charge transfer complexes with trinitrofluorenone, with Huckel coefficients of the resonance integral in the expression for the highest occupied molecular orbital energy level, and with pabsorption band spectra.
Journal ArticleDOI
Electron-transfer and complex formation in the excited state
TL;DR: In this paper, a broad structureless emission band about 5000 cm1 was observed to increase with increasing electron donor concentration at the expense of the fluorescence intensity of the hydrocarbon, thereby following the same Stern-Volmer-type relation as does the well known excimer fluorescence.