Viscosity of liquid toluene at temperatures from 25 to 150.degree.C and at pressures up to 30 MPa

Krall, A. H.; Sengers, J. V.; Kestin, J.

doi:10.1021/je00007a021

Cited by 54 publications

(33 citation statements)

References 20 publications

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“…The data of Dymond and Robertson 12 were obtained with a capillary viscometer with buoyancy, kinetic energy, and temperature effects being considered. The data of Krall et al 16 were obtained with an oscillating disk viscometer calibrated with water, with an accuracy of 0.5%. The kinetic energy correction was accounted for.…”

Section: Primary Datamentioning

confidence: 99%

Standard Reference Data for the Viscosity of Toluene

Santos¹,

Castro²,

Dymond³

et al. 2005

Journal of Physical and Chemical Reference Data

139

100

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Viscosity is an important transport property for the optimum design of a chemical process plant and for the development of molecular theories of the liquid state. A large amount of experimental viscosity data has been produced for all types of liquids, from alternative refrigerants to molten salts and molten metals. The accuracy of these data is related to the operating conditions of the instrument and, for this purpose as well as for the calibration of relative instruments, standard reference data for viscosity are necessary over a wide range of temperatures. New experimental data on the viscosity of liquid toluene along the saturation line have been obtained recently, mostly at low temperatures. The quality of the data is such that recommended values can be proposed with uncertainties of 0.5% ͑95% confidence level͒ for 260 KрTр370 K and 2% for 210 KрT Ͻ260 K and 370 KϽTр400 K. A discussion about the uncertainties in the measurements and about the purity of the samples is made. The proposed value for the viscosity of liquid toluene at 298.15 K and 0.1 MPa is ϭ554.2Ϯ3.3 Pa s.

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Section: Primary Datamentioning

confidence: 99%

Standard Reference Data for the Viscosity of Toluene

Santos¹,

Castro²,

Dymond³

et al. 2005

Journal of Physical and Chemical Reference Data

139

100

View full text Add to dashboard Cite

show abstract

“…The same modelling can be performed at multiple temperatures by repeating the statistical mechanical calculation of the free energies at the modified T , and by taking the appropriate experimental value for the solvent viscosity . However, agreement with experiment for the resulting unmodified model deteriorates upon switching to the other two temperatures studied experimentally, that is, 403 and 383 K. As an example, the calculated rates for the formation of 13 n at these temperatures are compared with experimental data in Figure .…”

Section: Resultsmentioning

confidence: 99%

“…The viscosity value h for toluene( the solventu sed in the experiments modelled here) is known as af unction of temperature and pressure; [15] for example, it is around 2.07 10 À4 kg m À1 s À1 for at emperature of 423 Ka nd ap ressure of 100 atm.…”

Section: Resultsmentioning

confidence: 99%

Computational Modelling of Selectivity in Cobalt‐Catalyzed Propene Hydroformylation

Szlapa

Harvey

2018

Chemistry A European J

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A mechanistic model for the cobalt-catalyzed hydroformylation of propene, based on density functional theory and coupled cluster electronic structure calculations and transition state theory, is proposed to explain the experimentally observed reactivity and selectivity. The electronic structure calculations provide very accurate energies, which are used with transition state theory to compute rate constants; the kinetics of the network of coupled reactions are then modelled numerically for this organometallic reaction. The model accounts well for the dependence of rate on the concentrations of catalysts and reagents, and also on the temperature, and the agreement with experiment is improved still further upon making small adjustments to the ab initio calculated free energy values. The calculations provide detailed kinetic insight into the mechanism of hydroformylation and the role of various elementary steps in defining reactivity and selectivity.

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“…[16c] They are assumed to be diffusioncontrolled, with rate constants in solution given by the approximate expression k = 8 k B T/3 h, where k B is Boltzmanns constant, T is temperature, and h is the solvent viscosity. [22] For toluene at 150 8C and 100 bar, h is 2.09 10 À4 Pa s, [23] yielding a diffusion-controlled rate constant of 4.49 10 10 m À1 s À1 at 150 8C.…”

Section: Angewandte Chemiementioning

confidence: 99%

“…The concentration [1] is related to the total concentration of cobalt [Co], which is twice the nominal value of [23]:…”

Section: Angewandte Chemiementioning

confidence: 99%

Computational Kinetics of Cobalt‐Catalyzed Alkene Hydroformylation

2014

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Density functional theory, coupled-cluster theory, and transition state theory are used to build a computational model of the kinetics of phosphine-free cobalt-catalyzed hydroformylation and hydrogenation of alkenes. The model provides very good agreement with experiment, and enables the factors that determine the selectivity and rate of catalysis to be determined. The turnover rate is mainly determined by the alkene coordination step.Cobalt-catalyzed hydroformylation, which was discovered 75 years ago based on earlier work at the Max Planck Institute for Coal Research, is the first reported metalcomplex-catalyzed industrial process. [1] Though rhodium catalysts have largely superseded cobalt systems because of greater efficiency, cobalt catalysts are cheaper, less toxic, and more thermally stable, and continue to be used. [2,3] Thus there continues to be much interest in the development of modified cobalt catalysts with increased activity, longevity, regioselectivity, and chemoselectivity especially with respect to avoiding wasteful alkene substrate hydrogenation. For each of these aspects of catalyst improvement, a detailed understanding of the hydroformylation mechanism is pivotal.Based on the mechanistic work of Heck and Breslow [4] and subsequent studies, [5] the hydroformylation mechanism with both rhodium and cobalt systems is quite well understood. Intermediates such as cobalt acyl tetracarbonyls [RCOCo(CO) 4 ] or phosphine derivatives thereof [RCOCo(-CO) 3 L] (where L = PR 3 ) have been detected under catalytic conditions, [4,6] and their reactivity studied. [7] The reactivity of the corresponding unsaturated intermediate [RCOCo(-CO) 2 L] obtained by flash photolysis has also been carefully examined. [8] Kinetics are available, in particular a systematic study [9] of the rate of hydroformylation of propene by [HCo(CO) 4 ], which gave the following empirical rate law:

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Viscosity of liquid toluene at temperatures from 25 to 150.degree.C and at pressures up to 30 MPa

Cited by 54 publications

References 20 publications

Standard Reference Data for the Viscosity of Toluene

Standard Reference Data for the Viscosity of Toluene

Computational Modelling of Selectivity in Cobalt‐Catalyzed Propene Hydroformylation

Computational Kinetics of Cobalt‐Catalyzed Alkene Hydroformylation

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