DICHLORINE HEXOXIDE

1938 ◽  
Vol 16b (11) ◽  
pp. 382-389 ◽  
Author(s):  
M. H. Kalina ◽  
J. W. T. Spinks
Keyword(s):  
Molecular Weight ◽  
Carbon Tetrachloride ◽  
Quantum Yield ◽  
Physical Properties ◽  
Extinction Coefficient ◽  
Quantitative Estimation ◽  
Wave Length ◽  
Colorimetric Method ◽  
Green Light ◽  
Carbon Tetrachloride Solution

Some chemical and physical properties of dichlorine hexoxide are described and attention is drawn to its dangerous property of exploding violently on contact with organic substances.The extinction coefficient of solutions of dichlorine hexoxide in carbon tetrachloride solution for a wave-length of 5460 Å has been measured and found to be 2.4, which is very much less than that of liquid dichlorine hexoxide for the same wave-length. A colorimetric method is described for the quantitative estimation of dichlorine hexoxide in solutions. The molecular weight of dichlorine hexoxide in carbon tetrachloride solution has been redetermined, and it confirms the formula Cl2O6.Solutions of dichlorine hexoxide in carbon tetrachloride are decomposed photochemically by green light. Gaseous chlorine trioxide (ClO3) is decomposed photochemically by λ3650. Its decomposition is photosensitized by chlorine and bromine, the quantum yield in the chlorine sensitized reaction being about 1.

THE PHOTODECOMPOSITION OF CHLORINE DIOXIDE IN CARBON TETRACHLORIDE SOLUTION

1937 ◽  
Vol 15b (12) ◽  
pp. 499-524 ◽  
Author(s):  
J. W. T. Spinks ◽  
H. Taube
Keyword(s):  
Thermal Decomposition ◽  
Carbon Tetrachloride ◽  
Quantum Yield ◽  
Light Intensity ◽  
Quantum Efficiency ◽  
Chlorine Dioxide ◽  
Concentration Effects ◽  
Low Light ◽  
Carbon Tetrachloride Solution ◽  
Chlorine Monoxide

Insolation of carbon tetrachloride solutions of chlorine dioxide initiates a thermal decomposition, the magnitude of which may exceed that for the photoreaction with low light intensity. This thermal decomposition is inhibited by keeping the solutions at 3 °C. or by adding water.In contradiction to the findings of other investigators, it is found that chlorine and oxygen are not the only products of photodecomposition. As products of the photodecomposition of chlorine dioxide at the wave-lengths 3650 and 4360 Å, the oxides Cl2O, Cl2O6, and Cl2O7 as well as chlorine and oxygen appear. The quantum efficiency at λ 3650 Å is 2, and at 4360 Å, 1.In the unsensitized decomposition, concentration effects are observed which are greatly decreased when the solutions are stirred.In the bromine sensitized decomposition with 5460 Å, there is less chlorine monoxide but relatively as much Cl2O6 and Cl2O7 formed as in the unsensitized reaction.In the sensitized decomposition the quantum yield is independent of the concentration of chlorine dioxide, but depends on the light intensity. The observed quantum yield for the sensitized reaction is 0.2 to 0.3.Mechanisms for the photo-reactions have been proposed.

Photolysis of Di-tert-butyl Peroxide in Solution

1974 ◽  
Vol 52 (13) ◽  
pp. 2491-2492 ◽  
Author(s):  
Eduardo Lissi
Keyword(s):  
Carbon Tetrachloride ◽  
Quantum Yield ◽  
Gas Phase ◽  
Hydrocarbon Concentration ◽  
Tert Butyl ◽  
Carbon Tetrachloride Solution ◽  
Butyl Peroxide ◽  
Peroxide Molecule

Di-tert-butyl peroxide has been photolyzed at 3130 Å in carbon tetrachloride solution in the presence of cyclohexane. The quantum yield of free tert-butoxy radicals was 1.9 ± 0.1, independent of the hydrocarbon concentration. Unlike results obtained in the gas phase at 2537 Å, no evidence for the quenching of the excited peroxide molecule could be detected.

The photochemical decomposition of dicumyl peroxide and cumene hydroperoxide in solution

1956 ◽  
Vol 237 (1211) ◽  
pp. 464-475 ◽  
Keyword(s):  
Carbon Tetrachloride ◽  
Quantum Yield ◽  
Benzyl Alcohol ◽  
Main Product ◽  
Cumene Hydroperoxide ◽  
Quantum Yields ◽  
Dicumyl Peroxide ◽  
Carbon Tetrachloride Solution ◽  
Dimethyl Benzyl ◽  
Photochemical Decomposition

The photochemical decomposition of dicumyl peroxide and cumene hydroperoxide in the absence of oxygen has been investigated in two solvents. Reaction mechanisms have been suggested from a consideration of the products and the quantum yields. Dicumyl peroxide forms αα '-dimethyl benzyl alcohol exclusively at 3130 Å in n -hexane. At 2537 Å a little acetophenone is also formed. In carbon tetrachloride solution the product at 3130 Å is acetophenone and at 2537 Å a mixture of acetone and acetophenone is formed. In n -hexane the main product from cumene hydroperoxide is αα '-dimethyl benzyl alcohol. In carbon tetrachloride on the other hand acetone and acetophenone and a dark polymer are formed. For cumene hydroperoxide in n -hexane at 3130 Å the quantum yield is 1⋅57 at 20°C, the chain reaction being sustained by radicals formed from the solvent. In carbon tetrachloride solution the quantum yield is 0⋅75.

THE BROMINE-SENSITIZED DECOMPOSITION OF CHLORINE MONOXIDE IN GREEN LIGHT

1937 ◽  
Vol 15b (3) ◽  
pp. 113-123 ◽  
Author(s):  
A. G. Brown ◽  
J. W. T. Spinks
Keyword(s):  
Quantum Yield ◽  
Chlorine Dioxide ◽  
Wave Length ◽  
Green Light ◽  
Dark Reaction ◽  
Chlorine Monoxide

Chlorine monoxide undergoes a bromine-sensitized decomposition in light of wave-length 5460 A. The reaction involves short chains and is accompanied by an appreciable dark reaction. The quantum yield is 4.3 at 19 °C. A decrease in pressure occurring near the end of the reaction has been shown to be a photochemical effect, and it is due probably to the bromine-sensitized decomposition of chlorine dioxide formed during the combined light and dark reactions.A mechanism similar to that described by Finkelnburg, Schumacher and Stieger for the unsensitized reaction appears to account for most of the observations.

Synthesis and Characterization of ROSA Dye - A Rhodamine B-type Fluorophore, Suitable for Bioconjugation and Fluorescence Studies in Live Cells

2019 ◽  
Vol 26 (10) ◽  
pp. 758-767
Author(s):  
Vicente Rubio ◽  
Vijaya Iragavarapu ◽  
Maciej J. Stawikowski
Keyword(s):  
Quantum Yield ◽  
Cancer Cells ◽  
Fluorescent Probe ◽  
Extinction Coefficient ◽  
Rhodamine B ◽  
Solid Phase ◽  
Total Yield ◽  
Molar Extinction Coefficient ◽  
Αvβ3 Integrin ◽  
Αvβ3 Integrins

Background: Herein we report the multigram-scale synthesis, characterization and application of a rhodamine B-based fluorophore (ROSA) suitable for fluorescent studies in biological applications. This fluorophore is devoid of rhodamine spirolactone formation and furthermore characterized by a high molar extinction coefficient (ϵ=87250 ± 1630 M-1cm-1) and quantum yield (φ) of 0.589 ± 0.070 in water. Reported here is also the application of ROSA towards synthesis of a ROSA-PEG-GRGDS-NH2 fluorescent probe suitable for live cell imaging of αvβ3 integrins for in vitro assays. Objective: The main objective of this study is to efficiently prepare rhodamine B derivative, devoid of spirolactone formation that would be suitable for bioconjugation and subsequent bioimaging. Methods: Rhodamine B was transformed into rhodamine B succinimide ester (RhoB-OSu) using N-hydroxysuccinimide. RhoB-OSu was further coupled to sarcosine to obtain rhodamine Bsarcosine dye (ROSA) in good yield. The ROSA dye was then coupled to a αvβ3 integrin binding sequence using standard solid-phase conditions. Resulting ROSA-PEG-GRGDS-NH2 probe was used to image integrins on cancer cells. Results: The rhodamine B-sarcosine dye (ROSA) was obtained in multigram scale in good total yield of 47%. Unlike rhodamine B, the ROSA dye does not undergo pH-dependent spirolactone/spirolactam formation as compared with rhodamine B-glycine. It is also characterized by excellent quantum yield (φ) of 0.589 ± 0.070 in water and high molar extinction coefficient of 87250 ± 1630 M-1cm-1. ROSA coupling to the RGD-like peptide was proved to be efficient and straightforward. Imaging using standard filters on multimode plate reader and confocal microscope was performed. The αvβ3 integrins present on the surface of live WM-266-4 (melanoma) and MCF- 7 (breast cancer) cells were successfully imaged. Conclusion: We successfully derivatized rhodamine B to create an inexpensive, stable and convenient to use fluorescent probe. The obtained derivative has excellent photochemical properties and it is suitable for bioconjugation and many imaging applications.

Linear and high-molecular-weight poly-porphyrins for efficient photodynamic therapy

2021 ◽  
Author(s):  
Nan Zheng ◽  
Xiahui Li ◽  
Shangwei Huangfu ◽  
Kangkai Xia ◽  
Ruofei Yue ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Singlet Oxygen ◽  
High Molecular Weight ◽  
Linear Poly ◽  
High Molecular Weight Poly

A linear poly-porphyrin with high Mw and conjugated by PEG and acetazolamide was developed with enhanced singlet oxygen quantum yield, improved photo-toxicity and excellent in vivo photodynamic therapy.

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