Determination of the rate constants for chain transfer with the monomer and hydrogen in Ziegler-Natta polymerization

1976 ◽  
Vol 5 (4) ◽  
pp. 429-434 ◽  
Author(s):  
V. I. Zakharov ◽  
N. B. Chumaevskii ◽  
Z. K. Bulatova ◽  
G. D. Bukatov ◽  
Yu. I. Yermakov
Keyword(s):  
Rate Constants ◽  
Chain Transfer

Synthesis of highly reactive polyisobutylene by catalytic chain transfer in hexanes at elevated temperatures; determination of the kinetic parameters

2017 ◽  
Vol 8 (18) ◽  
pp. 2852-2859 ◽  
Author(s):  
Tota Rajasekhar ◽  
Jack Emert ◽  
Rudolf Faust
Keyword(s):  
Kinetic Parameters ◽  
Rate Constants ◽  
Chain Transfer ◽  
Elevated Temperatures ◽  
Polymerization Rate ◽  
Carbenium Ions ◽  
Catalytic Chain Transfer ◽  
Highly Reactive Polyisobutylene ◽  
Increasing Temperature

The rate constants of activation/deactivation for dormant oxonium/active carbenium ions have been measured and related to the increasing polymerization rate with increasing temperature.

Determination of rate constants of redox reactions of second order from current-less potential-time curves by a simplified graphical-numerical method

1983 ◽  
Vol 48 (5) ◽  
pp. 1358-1367 ◽  
Author(s):  
Antonín Tockstein ◽  
František Skopal
Keyword(s):  
Numerical Method ◽  
Explicit Form ◽  
Rate Constant ◽  
Optimization Algorithm ◽  
Rate Constants ◽  
Redox Reactions ◽  
Second Order ◽  
Wide Region ◽  
Recurrent Formula

A method for constructing curves is proposed that are linear in a wide region and from whose slopes it is possible to determine the rate constant, if a parameter, θ, is calculated numerically from a rapidly converging recurrent formula or from its explicit form. The values of rate constants and parameter θ thus simply found are compared with those found by an optimization algorithm on a computer; the deviations do not exceed ±10%.

Determination of the Accurate Values of the Rate Constant and Thermodynamic Parameters for the Rotation About the C(sp2)-C(aryl) Bond; Adamantan-1-yl 3-Bromo-2,4,6-trimethylphenyl Ketone

1998 ◽  
Vol 63 (7) ◽  
pp. 955-966
Author(s):  
Eva Přibylová ◽  
Miroslav Holík
Keyword(s):  
Thermodynamic Parameters ◽  
Shape Analysis ◽  
Rate Constants ◽  
Line Shape ◽  
Microsoft Excel ◽  
Hindered Rotation ◽  
H Nmr ◽  
Line Shape Analysis ◽  
Coalescence Temperature

Four programs for the 1H NMR line shape analysis: two commercial - Winkubo (Bruker) and DNMR5 (QCPE 165) and two written in our laboratory - Newton (in Microsoft Excel) and Simtex (in Matlab) have been tested in order to get highly accurate rate constants of the hindered rotation about a single bond. For this purpose four testing criteria were used, two of them were also developed by us. As supplementary determinations the rate constants obtained for the coalescence temperature and for the thermal racemization of chromatographically separated enantiomers were used which fitted well the temperature dependence of the rate constants determined by the line shape analysis. As a test compound adamantan-1-yl 3-bromo-2,4,6-trimethylphenyl ketone was prepared and studied. It was shown that supermodified simplex method used in our algorithm (Simtex), though time consuming, gives the most accurate values of the rate constants and consequently the calculated thermodynamic parameters Ea, ∆H≠, and ∆S≠ lay in relatively narrow confidence intervals.

Determination of the Nucleophilicity of Tricarbonyliron Coordinated Cyclohepta-1,3,5-triene

1999 ◽  
Vol 64 (11) ◽  
pp. 1770-1779 ◽  
Author(s):  
Herbert Mayr ◽  
Karl-Heinz Müller
Keyword(s):  
Gibbs Energy ◽  
Ambient Temperature ◽  
Rate Constants ◽  
Second Order ◽  
Order Rate ◽  
Electrophilic Additions ◽  
Kinetics Of

The kinetics of the electrophilic additions of four diarylcarbenium ions (4a-4d) to tricarbonyl(η4-cyclohepta-1,3,5-triene)iron (1) have been studied photometrically. The second-order rate constants match the linear Gibbs energy relationship log k20 °C = s(E + N) and yield the nucleophilicity parameter N(1) = 3.69. It is concluded that electrophiles with E ≥ -9 will react with complex 1 at ambient temperature.

Interfacial catalysis by phospholipase A2: determination of the interfacial kinetic rate constants

Biochemistry ◽  
1991 ◽  
Vol 30 (29) ◽  
pp. 7283-7297 ◽  
Author(s):  
Otto G. Berg ◽  
Bao Zhu Yu ◽  
Joe Rogers ◽  
Mahendra Kumar Jain
Keyword(s):  
Phospholipase A2 ◽  
Rate Constants ◽  
Kinetic Rate ◽  
Kinetic Rate Constants ◽  
Interfacial Catalysis

Reactions of the hydroxyl radical. Part 2.—Determination of absolute rate constants

1965 ◽  
Vol 61 (0) ◽  
pp. 1417-1424 ◽  
Author(s):  
G. E. Adams ◽  
J. W. Boag ◽  
B. D. Michael
Keyword(s):  
Hydroxyl Radical ◽  
Rate Constants ◽  
Absolute Rate
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