Fluorescence quenching of a cationic porphyrin by cationic and anionic aromatics: formation of ground-state complexes

1987 ◽  
Vol 91 (27) ◽  
pp. 6614-6619 ◽  
Author(s):  
Koji. Kano ◽  
Takeshi. Nakajima ◽  
Shizunobu. Hashimoto
Keyword(s):  
Fluorescence Quenching ◽  
Ground State ◽  
Cationic Porphyrin

Fluorescence Quenching of Aminodiphenylamines with Chloromethanes

2002 ◽  
Vol 67 (8) ◽  
pp. 1154-1164 ◽  
Author(s):  
Nachiappan Radha ◽  
Meenakshisundaram Swaminathan
Keyword(s):  
Charge Transfer ◽  
Fluorescence Quenching ◽  
Ground State ◽  
Rate Constants ◽  
Quenching Mechanism ◽  
Quenching Rate ◽  
Charge Transfer Interaction ◽  
Electronically Excited ◽  
A Charge

The fluorescence quenching of 2-aminodiphenylamine (2ADPA), 4-aminodiphenylamine (4ADPA) and 4,4'-diaminodiphenylamine (DADPA) with tetrachloromethane, chloroform and dichloromethane have been studied in hexane, dioxane, acetonitrile and methanol as solvents. The quenching rate constants for the process have also been obtained by measuring the lifetimes of the fluorophores. The quenching was found to be dynamic in all cases. For 2ADPA and 4ADPA, the quenching rate constants of CCl4 and CHCl3 depend on the viscosity, whereas in the case of CH2Cl2, kq depends on polarity. The quenching rate constants for DADPA with CCl4 are viscosity-dependent but the quenching with CHCl3 and CH2Cl2 depends on the polarity of the solvents. From the results, the quenching mechanism is explained by the formation of a non-emissive complex involving a charge-transfer interaction between the electronically excited fluorophores and ground-state chloromethanes.

Fluorescence quenching in micelles in the presence of a probe-quencher ground-state charge-transfer complex

1993 ◽  
Vol 97 (43) ◽  
pp. 11242-11248 ◽  
Author(s):  
Marcelo H. Gehlen ◽  
Frans C. De Schryver
Keyword(s):  
Charge Transfer ◽  
Fluorescence Quenching ◽  
Ground State ◽  
Charge Transfer Complex ◽  
State Charge

scholarly journals Photochemical processes induced by the irradiation of 4-hydroxybenzophenone in different solvents

2015 ◽  
Vol 14 (11) ◽  
pp. 2087-2096 ◽  
Author(s):  
Francesco Barsotti ◽  
Marcello Brigante ◽  
Mohamed Sarakha ◽  
Valter Maurino ◽  
Claudio Minero ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Excited States ◽  
Ground State ◽  
Photochemical Processes ◽  
Triplet Excited States

The singlet and triplet excited states of 4-hydroxybenzophenone (4BPOH) undergo deprotonation in the presence of water to produce the anionic ground-state, causing fluorescence quenching and photoactivity inhibition.

Quenching of Silver Nanoparticles

2014 ◽  
Vol 781 ◽  
pp. 135-144 ◽  
Author(s):  
E. Thanikaivalan ◽  
R. Jothilakshmi
Keyword(s):  
Silver Nanoparticles ◽  
Optical Absorption ◽  
Fluorescence Quenching ◽  
Fluorescence Spectroscopy ◽  
Absorption Spectroscopy ◽  
Ground State ◽  
Fluorescence Emission ◽  
Quenching Of Fluorescence ◽  
Volmer Plot

Silver nanoparticles of different sizes have been prepared. Absorption spectroscopy reveals the formation of ground state complex. Fluorescence spectroscopy has been used to study the signatures of fluorescence quenching. Properties of N-(2-methylthiophenyl)-2-hydroxy-1-naphthaldimine (NMTHN) on silver nanoparticles has been investigated using optical absorption and fluorescence emission techniques. Quenching of fluorescence of N-(2-methylthiophenyl)-2-hydroxy-1-naphthaldimine has been found to decrease with increase in the size of the silver nanoparticles. The results of the quenching experiments were analyzed through Stern Volmer plot.

DNA duplex as a scaffold for a ground state complex formation between a zinc cationic porphyrin and phenylethynylpyren-1-yl

2014 ◽  
Vol 288 ◽  
pp. 76-81 ◽  
Author(s):  
Saymore Mutsamwira ◽  
Eric W. Ainscough ◽  
Ashton C. Partridge ◽  
Peter J. Derrick ◽  
Vyacheslav V. Filichev
Keyword(s):  
Complex Formation ◽  
Ground State ◽  
Dna Duplex ◽  
Cationic Porphyrin

scholarly journals Synergistic photoredox and copper catalysis by diode-like coordination polymer with twisted and polar copper–dye conjugation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yusheng Shi ◽  
Tiexin Zhang ◽  
Xiao-Ming Jiang ◽  
Gang Xu ◽  
Cheng He ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Coordination Polymer ◽  
Fluorescence Quenching ◽  
Ground State ◽  
Photoinduced Electron Transfer ◽  
Electronic Conductivity ◽  
Copper Catalysis ◽  
Reaction Conditions ◽  
Different Types ◽  
Inherent Problem

Abstract Synergistic photoredox and copper catalysis confers new synthetic possibilities in the pharmaceutical field, but is seriously affected by the consumptive fluorescence quenching of Cu(II). By decorating bulky auxiliaries into a photoreductive triphenylamine-based ligand to twist the conjugation between the triphenylamine-based ligand and the polar Cu(II)–carboxylate node in the coordination polymer, we report a heterogeneous approach to directly confront this inherent problem. The twisted and polar Cu(II)–dye conjunction endows the coordination polymer with diode-like photoelectronic behaviours, which hampers the inter- and intramolecular photoinduced electron transfer from the triphenylamine-moiety to the Cu(II) site and permits reversed-directional ground-state electronic conductivity, rectifying the productive loop circuit for synergising photoredox and copper catalysis in pharmaceutically valuable decarboxylative C(sp3)–heteroatom couplings. The well-retained Cu(II) sites during photoirradiation exhibit unique inner-spheric modulation effects, which endow the couplings with adaptability to different types of nucleophiles and radical precursors under concise reaction conditions, and distinguish the multi-olefinic moieties of biointeresting steride derivatives in their late-stage trifluoromethylation-chloration difunctionalisation.

The Association Properties of Iodide With Cetyltrimethylammonium Bromide Micelles as Revealed by Steady-State Fluorescence Quenching Measurements

1987 ◽  
Vol 40 (1) ◽  
pp. 201 ◽  
Author(s):  
E Blatt
Keyword(s):  
Steady State ◽  
Fluorescence Quenching ◽  
Stearic Acid ◽  
Partition Coefficient ◽  
Palmitic Acid ◽  
Ground State ◽  
Cetyltrimethylammonium Bromide ◽  
Steady State Fluorescence ◽  
Micelle Structure ◽  
Fluorescence Quenching Technique

The association behaviour of I- with cetyltrimethylammonium bromide micelles was investigated by the fluorescence quenching technique with 2-(9-anthroy1oxy) palmitic acid and 12-(9- anthroyloxy) stearic acid as probes. A 1 : 1 ground-state complex occurs between I- and 12-(9-anthroyloxy) stearic acid with an equilibrium constant, Kc , of 408 dm3 mol-l. In both cases I- partitions into the micelle with a partition coefficient, Kp , of about 365. The results show the importance of probe solubilization site and probe/quencher interaction in the elucidation of micelle structure and permeability.

Thionine Fluorescence Quenching by Metal Cations

1980 ◽  
Vol 35 (11) ◽  
pp. 1201-1206 ◽  
Author(s):  
G. Köhler ◽  
S. Solar ◽  
N. Getoff
Keyword(s):  
Fluorescence Quenching ◽  
Metal Ions ◽  
Salt Concentration ◽  
Ground State ◽  
Metal Cations ◽  
Fluorescence Yield ◽  
The Other ◽  
Quenching Rate ◽  
Quenching Mechanisms

Abstract The mechanism of the fluorescence quenching of aqueous thionine by various metal ions (Ce3+, Fe2+, Mn2+, Mg2+, Cs+ and Na+) was studied at pH = 2.5. The following Stern-Volmer constants (Ksv) were determined: KSV(Fe2+) == 1.13 dm3 mol-1, KSV(Mn2+) = 0.24 dm3 mol-1, KSV(Ce3+) = 0.24 dm3 mol-1, KSV(Cs+) - 0.03 dm3 mol-1. At concentrations below 1 mol.dm-3 Na2SO4 and MgSO4 are very weak quenchers (KSV(Na+ or Mg2+) = 0.007), but the influence on the fluorescence yield increases considerably at higher cation concentrations. This was attributed to the formation of ground state complexes between thionine and SO42- ions. The salt concentration affects considerably the quenching rate of Fe2+ ions, but much less so that of the other cations. Fluorescence quenching mechanisms are discussed.

Ground-state complex formation of perylene with pyromellitic dianhydride studied by static fluorescence quenching

1998 ◽  
Vol 8 (1) ◽  
pp. 67-72
Author(s):  
Horst Gebert ◽  
Wolfgang Kretzschmar ◽  
Wolfgang Regenstein
Keyword(s):  
Complex Formation ◽  
Fluorescence Quenching ◽  
Ground State ◽  
Pyromellitic Dianhydride

Combined static and dynamic intramicellar fluorescence quenching: effects on stationary and time-resolved Stern–Volmer experiments

2019 ◽  
Vol 21 (19) ◽  
pp. 10075-10085 ◽  
Author(s):  
Tim Kohlmann ◽  
Martin Goez
Keyword(s):  
Fluorescence Quenching ◽  
Ground State ◽  
Time Resolved ◽  
Consistent Model

It ain’t necessarily so—existing theories of combined quenching in micelles are flawed. We derive a consistent model, analyze its properties, and apply it to obtain information on ground-state complexes between fluorophore F and quencher Q.

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