Photochemical studies as a function of solvent viscosity. A new photochemical pathway in the reaction of (η5-C5H4Me)2Mo2(CO)6 with CCl4Electronic supplementary information (ESI) available: plots of quantum yields vs. viscosity for the photolysis of Cp′2Mo2(CO)6 in hexane–squalane, hexane–paraffin oil, THF–polyglyme, and ethanol–propylene glycol; table of quantum yields showing dependence on [CCl4]; table of values of fitting parameters in eqn. (3). See http://www.rsc.org/suppdata/pp/b2/b202112a/

2002 ◽  
Vol 1 (6) ◽  
pp. 418-420 ◽  
Author(s):  
Dale A. Braden ◽  
Eileen E. Parrack ◽  
David R. Tyler
Keyword(s):  
Propylene Glycol ◽  
Supplementary Information ◽  
Quantum Yields ◽  
Solvent Viscosity ◽  
Paraffin Oil ◽  
Fitting Parameters

scholarly journals Excited-state relaxation of some aminoquinolines

2006 ◽  
Vol 2006 ◽  
pp. 1-6 ◽  
Author(s):  
M. N. Khimich ◽  
B. M. Uzhinov
Keyword(s):  
Excited State ◽  
Fluorescence Spectra ◽  
Solvent Polarity ◽  
Quantum Yields ◽  
Absorption And Fluorescence Spectra ◽  
Molecular Fragments ◽  
Orientational Relaxation ◽  
Solvent Viscosity ◽  
Fluorescence Quantum Yields ◽  
Different Temperatures

The absorption and fluorescence spectra, fluorescence quantum yields and lifetimes, and fluorescence rate constants (kf) of 2-amino-3-(2′-benzoxazolyl)quinoline (I), 2-amino-3-(2′-benzothiazolyl)quinoline (II), 2-amino-3-(2′-methoxybenzothiazolyl)-quinoline (III), 2-amino-3-(2′-benzothiazolyl)benzoquinoline (IV) at different temperatures have been measured. The shortwavelength shift of fluorescence spectra of compounds studied (23–49 nm in ethanol) as the temperature decreases (the solvent viscosity increases) points out that the excited-state relaxation process takes place. The rate of this process depends essentially on the solvent viscosity, but not the solvent polarity. The essential increasing of fluorescence rate constantkf(up to about 7 times) as the solvent viscosity increases proves the existence of excited-state structural relaxation consisting in the mutual internal rotation of molecular fragments of aminoquinolines studied, followed by the solvent orientational relaxation.

Preliminary Evaluation of a Weibull Function for Fitting Slow-Component Eye Velocity over the Time Course of Caloric-Induced Nystagmus

1989 ◽  
Vol 32 (3) ◽  
pp. 681-687 ◽  
Author(s):  
C. Formby ◽  
B. Albritton ◽  
I. M. Rivera
Keyword(s):  
Time Course ◽  
Slow Component ◽  
Weibull Function ◽  
Preliminary Evaluation ◽  
Mathematical Function ◽  
Before And After ◽  
Best Fitting ◽  
Eye Velocity ◽  
Fitting Parameters ◽  
Weibull Equation

We describe preliminary attempts to fit a mathematical function to the slow-component eye velocity (SCV) over the time course of caloric-induced nystagmus. Initially, we consider a Weibull equation with three parameters. These parameters are estimated by a least-squares procedure to fit digitized SCV data. We present examples of SCV data and fitted curves to show how adjustments in the parameters of the model affect the fitted curve. The best fitting parameters are presented for curves fit to 120 warm caloric responses. The fitting parameters and the efficacy of the fitted curves are compared before and after the SCV data were smoothed to reduce response variability. We also consider a more flexible four-parameter Weibull equation that, for 98% of the smoothed caloric responses, yields fits that describe the data more precisely than a line through the mean. Finally, we consider advantages and problems in fitting the Weibull function to caloric data.

Molecular dynamics of poly(propylene) glycol in nanometer confinements

2000 ◽  
Vol 10 (PR7) ◽  
pp. Pr7-271-Pr7-274 ◽  
Author(s):  
A. Schönhals ◽  
H. Goering ◽  
K.-W. Brzezinka ◽  
Ch. Schick
Keyword(s):  
Molecular Dynamics ◽  
Propylene Glycol ◽  
Poly Propylene

Hydrogenolysis of glucose and fructose in glycol solutions over CuO-MgO-ZrO2 catalyst

2020 ◽  
pp. 48-55
Author(s):  
M.E. Sharanda ◽  
◽  
E.A. Bondarenko ◽  
Keyword(s):  
Ethylene Glycol ◽  
Propylene Glycol ◽  
Flow Reactor ◽  
General Trend ◽  
Raw Materials ◽  
Reaction Products ◽  
Renewable Raw Materials ◽  
High Partial Pressure ◽  
Zro2 Catalyst ◽  
Phase Process

Ethylene glycol and propylene glycol are important representatives of polyols. On an industrial scale, they are obtained from petrochemical raw materials. Within a decade, significant efforts were made for the producing of polyols from biologically renewable raw materials - carbohydrates. The general trend for carbohydrate hydrogenolysis includes application of liquid-phase process with the use of modified metal-oxide catalysts, at 120-120 ° C and pressure of 3MPa or above. So high pressure is used for the reason to increase hydrogen solubility, and also due to the high partial pressure of low boiling solvents. We supposed that usage of high boiling solvents could allow hydrogenolysis to be performed at the lower pressure. Ethylene glycol and propylene glycol are of particular interest as such kind of solvent since they are both the main products of glucose hydrogenolysis. In this work, the process of hydrogenolysis of glucose and fructose over Cu / MgO-ZrO2 catalyst have been studied at temperature range of 160-200 °C and a pressure of 0.1-0.3 MPa in a flow reactor. The solvents were simultaneously the target products of the reaction - ethylene glycol and / or propylene glycol. Gas chromatography and 13C NMR were used for the reaction products identification. It was found that the solubility of glucose in propylene glycol is 21 % by weight, and in ethylene glycol 62% by weight. It was pointed out that the process of hydrogenolysis can take place at a pressure close to atmospheric. Under these conditions, the conversion of hexoses reaches 96-100 %. The reaction products are preferably propylene glycol and ethylene glycol. The total selectivity for C3-2 polyols is 90-94 %, that is higher than in the hydrogenolysis of glucose in aqueous solution.

Highly Luminescent 4-Pyridyl-Extended Dithieno[3,2-b:2′,3′-d]phospholes

2020 ◽  
Author(s):  
Thomas Baumgartner ◽  
Paul Demay-Drouhard
Keyword(s):  
Electrochemical Properties ◽  
Quantum Yields

The unexpectedly challenging synthesis of 4-pyridyl-extended dithienophospholes is reported. The optical and electrochemical properties of the phosphoryl-bridged species were studied experimentally and computationally, and their properties compared to their non-<i>P</i>-bridged congeners. The 4-pyridyl-extended dithieno-phospholes display quantitative luminescence quantum yields in solution.<br><br>

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