The Kinetics of the Thermal Insertion Reaction of Tin(II) Halides with Cyclopentadienylnickel Carbonyl Dimer

1971 ◽  
Vol 49 (16) ◽  
pp. 2627-2630 ◽  
Author(s):  
P. F. Barrett ◽  
Ronald R. Clancy
Keyword(s):  
Kinetic Data ◽  
Activation Enthalpy ◽  
Insertion Reaction ◽  
Activation Entropy ◽  
Metal Bond ◽  
Metal Metal ◽  
Kinetics Of ◽  
Direct Attack ◽  
Bimolecular Mechanism

The kinetics of the thermal insertion of SnCl2 and SnBr2 into the metal–metal bond of [π-C5H5NiCO]2 have been studied. On the basis of the kinetic data a bimolecular mechanism, involving direct attack of the tin(II) halide on the nickel dimer, has been proposed. The thermal insertion with tin(II) bromide was found to proceed with an activation enthalpy of 19.4 ± 0.2 kcal/mol and an activation entropy of −8.8 ± 0.4 cal deg−1 mol−1. For the thermal insertion with tin(II) chloride a ΔH≠ and ΔS≠ of 22.5 ± 0.2 kcal/mol and −4.0 ± 0.2 cal deg−1 mol−1, respectively, were observed.

The kinetics of the thermal insertion reaction of tin(II) halides with cyclopentadienyliron dicarbonyl dimer

1970 ◽  
Vol 48 (21) ◽  
pp. 3300-3303 ◽  
Author(s):  
P. F. Barrett ◽  
Kenneth K. W. Sun
Keyword(s):  
Activation Energy ◽  
Kinetic Data ◽  
Activation Enthalpy ◽  
Visible Spectrum ◽  
Nucleophilic Attack ◽  
Insertion Reaction ◽  
Activation Entropy ◽  
Kcal Mole ◽  
Metal Metal ◽  
Kinetics Of

The kinetics of the thermal insertion reaction of SnBr2 and SnCl2 with the metal–metal bonded dimer [π-C5H3Fe(CO)2]2 have been studied by following the change in the visible spectrum. The kinetic data are consistent with a two-stage mechanism involving the formation of a carbonyl-bridged intermediate followed by nucleophilic attack by the halides on this intermediate. The formation of the intermediate requires an activation enthalpy of 38.0 ± 1.0 kcal/mole, and an activation entropy of 45.5 + 1.5 cal mole−1 deg−1. The activation energy required to break the Fe—Fe bond is estimated to be about 32 kcal/mole.

The Kinetics of the Insertion Reaction of Tin(II) Chloride with a Mono-substituted Derivative of Cyclopentadienyliron Dicarbonyl Dimer

1972 ◽  
Vol 50 (7) ◽  
pp. 972-976 ◽  
Author(s):  
P. F. Barrett ◽  
W. J. Jacobs
Keyword(s):  
Activation Enthalpy ◽  
Visible Spectrum ◽  
Insertion Reaction ◽  
Triphenyl Phosphite ◽  
Two Stage ◽  
Temperature Range ◽  
Metal Metal ◽  
Iron Iron ◽  
Kinetics Of

The kinetics of the thermal insertion reaction of SnCl2 with the metal–metal bonded complex (π-C5H5)2Fe2(CO)3P(OC6H5)3 have been studied by following the change in the visible spectrum in THF over the temperature range 40.0 to 55.0 °C. The data are consistent with a two-stage mechanism involving the formation of an intermediate in which the iron–iron bond has been broken but the carbonyl bridges are left intact. From the activation enthalpy of 23.4 ± 0.5 kcal/mol for the formation of the intermediate it is concluded that the triphenyl phosphite has brought about a weakening of the iron–iron bond.

The Kinetics of the Insertion Reaction of Tin(II) Chloride with Hexacarbonylbis(triphenylphosphite)dicobalt

1974 ◽  
Vol 52 (22) ◽  
pp. 3773-3777 ◽  
Author(s):  
Peter Fowler Barrett
Keyword(s):  
Electron Acceptor ◽  
Activation Enthalpy ◽  
Visible Spectrum ◽  
Insertion Reaction ◽  
Two Stage ◽  
Temperature Range ◽  
Metal Metal ◽  
Enthalpy And Entropy ◽  
Kinetics Of

The kinetics of the thermal insertion reaction of SnCl2 with the metal–metal bonded complex [P(OC6H5)3Co(CO)3]2 have been studied by following the change in the visible spectrum in THF over the temperature range 35.0 to 55.0 °C. The activation enthalpy and entropy for the reaction are 24.7 ± 0.4 kcal/mol and 2.4 ± 1.3 cal mol−l deg−1 respectively. The data are consistent with a two-stage mechanism identical to that proposed for the corresponding reaction with [P(n-C4H9)3Co(CO)3]2 and from a comparison of the two reactions it is concluded that the cobalt–cobalt bond is slightly weakened when tributylphosphine is replaced by the better π-electron acceptor triphenylphosphite. The insertion products [LCo(CO)3]2SnCl2 are shown to undergo further reaction with [LCo(CO)3]2 to form [LCo(CO)3]3SnCl (L = CO, P(n-C4H9)3, P(OC6H5)3).

scholarly journals The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate

2000 ◽  
Vol 65 (12) ◽  
pp. 857-866
Author(s):  
Mladjen Micevic ◽  
Slobodan Petrovic
Keyword(s):  
Kinetic Data ◽  
Reaction Rate ◽  
Frequency Factor ◽  
Reaction Rate Constant ◽  
Order Reaction ◽  
Activation Entropy ◽  
Second Order Reaction ◽  
Third Order ◽  
First Order ◽  
Kinetics Of

The alcoholysis of 1,2,2-trimethylpropyl-methylfluorophosphonate (soman) was examined with a series of alkoxides and in corresponding alcohols: methanol, ethanol, 1-propanol, 2-propanol, 2-methoxyethanol and 2-ethoxyethanol. Soman reacts with the used alkoxides in a second order reaction, first order in each reactant. The kinetics of the reaction between 1,2,2-trimethylpropyl-methylfluorophosphonate and ethanol in the presence of diethylenetriamine was also examined. A third order reaction rate constant was calculated, first order in each reactant. The activation energy, frequency factor and activation entropy were determined on the basis of the kinetic data.

The photoinsertion of tin(II) chloride into the metal–metal bond of hexacarbonylbis(tri-n-butylphosphine)dicobalt

1977 ◽  
Vol 55 (12) ◽  
pp. 2279-2285 ◽  
Author(s):  
Peter F. Barrett ◽  
Arnold Fox ◽  
Raymond E. March
Keyword(s):  
Quantum Yield ◽  
Quantum Yields ◽  
Insertion Reaction ◽  
Absorption Bands ◽  
Intense Band ◽  
Visible Absorption ◽  
Metal Bond ◽  
Metal Metal ◽  
Uv Visible ◽  
Limiting Value

The photochemical insertion reaction of SnCl2 into the metal–metal bond of [P(n-C4H9)3Co(CO)3]2 has been studied in THF at 23.0 °C at the irradiating wavelengths 365 nm, 436 nm, and 546 nm. At 365 nm, the quantum yield for the reaction increases with increasing concentration of SnCl2 and approaches a limiting value of 1.0. At 436 nm, however, the quantum yield increases above 1.0 and at 546 nm, quantum yields as high as 6 were measured. The uv–visible absorption spectrum of [P(n-C4H9)3Co(CO)3]2 shows an intense band at 372 nm and a broad shoulder at about 440 nm. A simple mechanism is proposed to operate on irradiation at 365 nm due to absorption by the intense band, but a more complicated chain mechanism is suggested to operate at 546 nm as a result of absorption by the lower energy shoulder band. It appears that both mechanisms operate on irradiation at 436 nm due to the overlap of the two absorption bands at this wavelength.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (03) ◽  
pp. 100-103 ◽  
Author(s):  
C. Schümichen ◽  
J. Waiden ◽  
G. Hoffmann
Keyword(s):  
Glomerular Filtration ◽  
Renal Clearance ◽  
Plasma Protein ◽  
Kinetic Data ◽  
Adult Rats ◽  
Compound A ◽  
Extravascular Space ◽  
Tubular Cells ◽  
Glomerular Filtrate ◽  
Kinetics Of

SummaryThe kinetic data of two different 99mTc-Sn-pyrophosphate compounds (compound A and B) were evaluated in non-adult rats. Only compound A concentrated in bone. Both compounds dispersed rapidly in the intravascular as well as the extravascular space. The plasma protein bond of both compounds increased with time after injection and impaired both the renal clearance of both compounds and the bone clearance of compound A. The renal clearance of both compounds was somewhat above that of 5 1Cr-EDTA. It is concluded that compound A and B is mainly excreted by glomerular filtration. About one fourth of the glomerular filtrate of compound B is reabsorbed and accumulated by the tubular cells.

Kinetics of catalytic conversion of methanol at higher pressures

1980 ◽  
Vol 45 (12) ◽  
pp. 3402-3407 ◽  
Author(s):  
Jaroslav Bartoň ◽  
Vladimír Pour
Keyword(s):  
Low Temperature ◽  
Reaction Kinetics ◽  
Water Vapour ◽  
Kinetic Data ◽  
Catalytic Conversion ◽  
The Given ◽  
Kinetics Of

The course of the conversion of methanol with water vapour was followed on a low-temperature Cu-Zn-Cr-Al catalyst at pressures of 0.2 and 0.6 MPa. The kinetic data were evaluated together with those obtained at 0.1 MPa and the following equation for the reaction kinetics at the given conditions was derived: r = [p(CH3OH)p(H2O)]0.5[p(H2)]-1.3.

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