Photolysis of Di-t-butylnitroxide

1982 ◽  
Vol 35 (3) ◽  
pp. 509 ◽  
Author(s):  
JM Coxon ◽  
E Patsalides
Keyword(s):  
Excited State ◽  
Light Intensity ◽  
Crystalline Solid ◽  
First Order ◽  
Deaerated Solution

Di-t-butylnitroxide (1) on photolysis in methylcyclohexane gives in addition to t-butoxy(di-t-buty1)-amine (7) and photolabile 2-methyl-2-nitrosopropane (2) a low yield of a white crystalline solid identified as a mixture of di-t-butylhydroxylammonium nitrate (13) and nitrite (14). Photolysis proceeds from the excited state produced by a π-π* transition, and in aerated solution is first order both with respect to nitroxide and light intensity. More complex kinetics are observed in deaerated solution.

scholarly journals Numerical Solution of the Spinor-Spinor Bethe-Salpeter Equation in Functional Nonlinear Spinor Theory

1975 ◽  
Vol 30 (5) ◽  
pp. 656-671
Author(s):  
W. Bauhoff
Keyword(s):  
Angular Momentum ◽  
Excited State ◽  
Variational Method ◽  
Numerical Solution ◽  
High Precision ◽  
Nonlinear Spinor ◽  
Spinor Theory ◽  
First Order ◽  
Scalar Mesons ◽  
Functional Methods

AbstractThe mass eigenvalue equation for mesons in nonlinear spinor theory is derived by functional methods. In second order it leads to a spinorial Bethe-Salpeter equation. This is solved by a variational method with high precision for arbitrary angular momentum. The results for scalar mesons show a shift of the first order results, obtained earlier. The agreement with experiment is improved thereby. An excited state corresponding to the η' is found. A calculation of a Regge trajectory is included,too.

scholarly journals Hinged and Wide: A New P^P Ligand for Emissive [Cu(P^P)(N^N)][PF6] Complexes

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3934 ◽  
Author(s):  
Sarah Keller ◽  
Matthias Bantle ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft
Keyword(s):  
Mass Spectrometry ◽  
Excited State ◽  
Quantum Yield ◽  
Delayed Fluorescence ◽  
Ionization Mass ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Single Crystal Structures ◽  
Photoluminescence Quantum Yield ◽  
Deaerated Solution

Heteroleptic [Cu(BIPHEP)(N^N)][PF6] complexes (BIPHEP = 1,1′-biphenyl-2,2′-diylbis(diphenylphosphane)), in which N^N is 2,2′-bipyridine (bpy), 6-methyl-2,2′-bipyridine (6-Mebpy), 6-ethyl-2,2′-bipyridine (6-Etbpy), or 5,5′-dimethyl-2,2′-bipyridine (5,5′-Me2bpy), have been synthesized and characterized using multinuclear NMR spectroscopies and electrospray ionization mass spectrometry. The single crystal structures of [Cu(BIPHEP)(bpy)][PF6]∙CH2Cl2, [Cu(BIPHEP)(5,5′-Me2bpy)][PF6]∙CH2Cl2, [Cu(BIPHEP)(6-Mebpy)][PF6]∙Et2O∙0.5H2O and [Cu(BIPHEP)(6-Etbpy)][PF6] confirm distorted tetrahedral {Cu(P^P)(N^N)} coordination environments. Each compound shows a quasi-reversible Cu+/Cu2+ process. In deaerated solution, the compounds are weak emitters. Powdered samples are yellow emitters (λemmax in the range 558–583 nm) and [Cu(BIPHEP)(5,5′-Me2bpy)][PF6] exhibits the highest photoluminescence quantum yield (PLQY = 14%). On cooling to 77 K (frozen 2-methyloxolane), the emission maxima are red-shifted and the excited state lifetimes increase from τ1/2 < 8 μs, to τ1/2 values of up to 53 μs, consistent with the compounds with N^N = 6-Mebpy, 6-Etbpy and 5,5′-Me2bpy exhibiting thermally activated delayed fluorescence (TADF).

scholarly journals Mass spectra of triply heavy charm-beauty baryons

2019 ◽  
Vol 202 ◽  
pp. 06001
Author(s):  
Zalak Shah ◽  
Ajay Kumar Rai
Keyword(s):  
Excited State ◽  
Quark Model ◽  
Mass Spectra ◽  
Constituent Quark ◽  
Magnetic Moments ◽  
Constituent Quark Model ◽  
Potential Term ◽  
First Order ◽  
Regge Trajectories ◽  
First Order Correction

We extract the mass spectra of triply heavy charm-beauty baryons using Hypercentral constituent quark model. The first order correction is also added to the potential term of Hamiltonian. The radial and orbital excited state masses are also determined. Moreover, the Regge trajectories and magnetic moments are also given for these baryons.

Photolysis of 2,5- and 2,4-Dimethylpyrrole Vapors at Room Temperature

1972 ◽  
Vol 50 (11) ◽  
pp. 1678-1689 ◽  
Author(s):  
E. Chung Wu ◽  
Julian Heicklen
Keyword(s):  
Excited State ◽  
Free Radical ◽  
Room Temperature ◽  
Low Pressure ◽  
Incident Radiation ◽  
Ring Cleavage ◽  
Incident Wavelength ◽  
First Order ◽  
Electronically Excited State ◽  
Electronically Excited

Both 2,5- and 2,4-dimethylpyrrole vapors at pressures from 0.05 to 0.70 Torr were irradiated at 2139 and 2288 Å at room temperature. The products were H2, CH4, C2H6, and polymer. No ring cleavage products were found. Φ{H2} and Φ{CH4} were remarkably insensitive to which pyrrole was used, its pressure,Ia, or the wavelength of the incident radiation. They were ~0.10–0.15 and ~0.01–0.02, respectively. Φ{C2H6} was comparable to Φ{CH4} and was also invariant to which substrate was used or the incident wavelength. However Φ{C2H6} did increase at low pressure or as Ia was reduced.The effect of scavengers showed that the products were produced mainly from free radical precursors. The main primary steps are:[Formula: see text]where DMP* is an electronically excited state of the dimethylpyrrole and Fa and Fb are radical fragments. Experiments with quenching gases showed that DMP* could be quenched, but that this reaction was less important than the first-order steps below 1 Torr.

scholarly journals Use of semi-conducting bismuth sulfide as a photocatalyst for degradation of rose bengal

2011 ◽  
Vol 30 (2) ◽  
pp. 229 ◽  
Author(s):  
Shweta Sharma ◽  
Rakshit Ameta ◽  
R. K. Malkani ◽  
Suresh C. Ameta
Keyword(s):  
Light Intensity ◽  
Rose Bengal ◽  
Bismuth Sulfide ◽  
Optimum Conditions ◽  
First Order ◽  
First Order Kinetics ◽  
Degradation Of Dyes ◽  
Textile Dyeing ◽  
Rate Of Reaction ◽  
Pseudo First Order

Different methods have been adopted for the removal and degradation of dyes from effluents of textile, dyeing and printing industries. These methods have their own merits and drawbacks. In the present investigation, bismuth sulfide has been used as a photocatalyst for the degradation of rose Bengal. The effect of different parameters like the pH, concentration of dye solution, amount of semiconductor and light intensity on the rate of reaction has been investigated. The reaction follows pseudo-first order kinetics. The optimum conditions were obtained as: [rose Bengal] = 1.60·10–5 M; Bi2S3 = 0.10 g; pH = 8.5, and light intensity = 50.0 mW·cm–2. The rate constant was 4.68·10–5 sec–1. A mechanism has been proposed for the degradation of rose Bengal involving hydroxyl radicals.

Photocatalytic degradation of parathion in aqueous TiO2 dispersion: the effect of hydrogen peroxide and light intensity

1998 ◽  
Vol 37 (8) ◽  
pp. 187-194 ◽  
Author(s):  
Tsu-feng Chen ◽  
Ruey-an Doong ◽  
Wen-gang Lei
Keyword(s):  
Hydrogen Peroxide ◽  
Light Intensity ◽  
Photocatalytic Degradation ◽  
Photocatalytic Oxidation ◽  
Pseudo First Order Reaction ◽  
Direct Photolysis ◽  
First Order ◽  
The Relationship ◽  
Effect Of Light ◽  
H2o2 System

The photodegradation of parathion in the direct photolysis, UV/TiO2, UV/H2O2 and UV/TiO2/H2O2 systems was investigated at 25°C. The effect of light intensity was also examined to clarify the relationship between the photo flux and decomposition rate of parathion. Results of the study demonstrated that no obvious degradation of parathion in dark reaction occurred within 24 hours. However, the addition of TiO2 and/or H2O2 promotes the degradation efficiency of parathion. Adding H2O2 was more effective in the photocatalytic oxidation of parathion than TiO2. Also, hydrogen peroxide was found as an intermediate with the maximum concentration of 55 μM in UV/TiO2 system during the photodegradation of parathion. A higher intensity of lamp could increase the degradation rate of parathion. However, the quantum efficiency for degradation of parathion decreased from 0.053 to 0.006 when light intensity increased from 100 W to 450W. Photodecomposition followed a pseudo-first-order reaction. The rate constants of parathion ranged from 0.003 min−1 for direct photolysis to 0.023 min−1 for UV/TiO2/H2O2 system. This study indicated that photocatalytic degradation is a highly promising technology for detoxifying parathion.

Disinfection effects on E. coli using TiO2/UV and solar light system

2002 ◽  
Vol 2 (1) ◽  
pp. 181-190 ◽  
Author(s):  
I.-H. Cho ◽  
I.-Y. Moon ◽  
M.-H. Chung ◽  
H.-K. Lee ◽  
K.-D. Zoh
Keyword(s):  
Light Intensity ◽  
Flow Rate ◽  
Alternative Energy ◽  
Advanced Oxidation Process ◽  
Uv Light ◽  
Solar Light ◽  
Survival Ratio ◽  
E Coli ◽  
First Order ◽  
First Order Kinetics

First, a continuous flow TiO2/UV reactor was designed and developed in order to examine E. coli disinfection effect using UV light. The optimum conditions for disinfection such as flow rate, light intensity, TiO2 concentration, initial E. coli concentration were examined. The results are as follow (i) The use of the quartz device and TiO2 (anatase) resulted in killing of E. coil within minutes. (ii) Photocatalytic disinfection with UV light in the presence of TiO2 more effectively killed E. coli than UV or TiO2 adsorption only. (iii) As flow rate increased, the survival ratio of E. coli decreased, but over 3 L/min of flow rate, the efficiency was limited. (iv) E. coli survival ratio decreased linearly with increasing UV light intensity. (v) The dosage of TiO2 affected the E. coli disinfection efficiency, and above 0.1 wt% TiO2 concentration, the disinfection was less effective because TiO2 particles may result in screening off the light. (ri) The disinfection reaction follows first-order kinetics. Secondly, outdoor experiments with natural sunlight instead of artificial UV light in TiO2 reactors were also conducted to investigate alternative energy source applicability on E. coli disinfection. It is found that the presence of clouds in the sky markedly increased the time required for killing E. coli and the bacteria cells also disappeared with a first-order kinetics. On the basis of these experimental observations, the disinfection of E. coli using TiO2 under solar light irradiation can be a feasible application of the advanced oxidation process.

The Characteristics of All-Optical Switching and Modulation in Phenoxy-Phthalocyanines Liquid

2013 ◽  
Vol 284-287 ◽  
pp. 2830-2834
Author(s):  
Yun Dong Zhang ◽  
Cheng Bao Yao ◽  
Hai Tao Yin ◽  
Chang Qiu Yu ◽  
Jin Li ◽  
...  
Keyword(s):  
Excited State ◽  
Light Intensity ◽  
Response Time ◽  
Optical Switching ◽  
Pump Light ◽  
Pump Probe ◽  
All Optical ◽  
Probe Experiment ◽  
Pump Probe Experiment ◽  
All Optical Switching

We present our experimental results on the measurements of excited state dynamics in 2, 9, 16, 23-phenoxy-phthalocyanine (Pc1) and 2, 9, 16, 23-phenoxy-phthalocyanine-zinc (Pc2) using the pump-probe experiment. The results show that the All-Optical Switching (A-OS) response time of Pc2 longer than that of Pc1, and switch-off and -on times of A-OS for Pc2 are 1.2 and 11.6 μs and for Pc1 are 2.3 and 7.8 μs at the same intensity. Moreover, analysis of modulation characteristics of A-OS shows that the stronger the light intensity of the pump light is, the smaller the normalized transmittance is and the shorter the response time of A-OS is. The consequences of such short lifetimes are also discussed in view of the strong A-OS properties of these molecules.

GENERALIZED BÄCKLUND–DARBOUX TRANSFORMATIONS IN ONE-DIMENSIONAL QUANTUM MECHANICS

2008 ◽  
Vol 05 (04) ◽  
pp. 605-640 ◽  
Author(s):  
JOSÉ F. CARIÑENA ◽  
ARTURO RAMOS
Keyword(s):  
Quantum Mechanics ◽  
Excited State ◽  
Differential Expression ◽  
Transformation Group ◽  
Darboux Transformations ◽  
Singular Case ◽  
One Dimensional ◽  
First Order ◽  
The Difference ◽  
Usual Problem

We consider an action of the group of curves in GL(2,ℝ) on the set of linear systems and therefore on the set of Schrödinger equations in full similarity with the action of the group of curves in SL(2,ℝ) on the set of Riccati equations considered in previous articles. We also consider the transformations defined by a first-order differential expression which carry solutions of a Schrödinger equation into solutions of another one. We find then two non-trivial situations: transformations which can be described by the previous transformation group, generalizing previous work by us, and transformations which are singular. We show that both situations appear, e.g., in the usual problem of partner Hamiltonians in quantum mechanics. We show that the difference Bäcklund algorithm, both in the finite and confluent versions, can be understood in terms of the above mentioned transformation group, the case of two exactly equal factorization energies being an instance of the singular case. We apply the generalized theorem relating three eigenfunctions of three different Hamiltonians to the generation of new potentials with a known (excited state) eigenfunction, starting from potentials of Coulomb, Morse and Rosen–Morse type. The potentials found are new and non-trivial.

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