Solvent effect on activation parameters for the neutral hydrolysis of phenyl trifluoroacetates in aqueous acetonitrile

The ruthenium(III) complex Hlnd trans-[RuCl4,(ind)2], with two trans-standing indazole (ind) ligands bound to ruthenium via nitrogen, shows remarkable activity in different tumor models in vitro and in vivo. The solvolysis of the complex trans-[RuCl4,(ind)2]- has been investigated by means of spectroscopic techniques (UV/vis, NMR)in different solvents. We investigated the indazolium as well as the sodium salt, the latter showing improved solubility in water. In aqueous acetonitrile and ethanol the solvolysis results in one main solvento complex. The hydrolysis of the complex is more complicated and depends on the pH of the solution as well as on the buffer system.

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Medium effects on activation parameters of alkaline hydrolysis of acetylmandelate ion

Journal of the Chemical Society A Inorganic Physical Theoretical ◽

10.1039/j19710001831 ◽

1971 ◽

pp. 1831 ◽

Cited By ~ 1

Author(s):

Apurba Kanti Ray ◽

Mihir Nath Das

Keyword(s):

Alkaline Hydrolysis ◽

Activation Parameters ◽

Medium Effects ◽

Hydrolysis Of

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PHYSICAL CHEMICAL STUDIES OF THE SURFACTANT DILAURYLDIMETHYLAMMONIUM BROMIDE (DLDMAB): AGGREGATION AND CATALYTIC PROPERTIES

Southern Brazilian Journal of Chemistry - Southern Brazilian Journal of Chemistry, Volume 28, No. 28, 2020 ◽

10.48141/sbjchem.v17.n17.2009.23_2009.pdf ◽

2009 ◽

Vol 17 (17) ◽

pp. 21-32

Author(s):

Elizabeth Fatima de Souza ◽

Silvia Dani ◽

Lavinel G. IONESCU

Keyword(s):

Thermodynamic Parameters ◽

Catalytic Properties ◽

Activation Parameters ◽

Critical Micellar Concentration ◽

Physical Chemical ◽

Chemical Studies ◽

Diphenyl Phosphate ◽

C 32 ◽

Free Energy Of Micellization ◽

Hydrolysis Of

The micellization of dilauryldimethylammonium bromide (DLDMAB) in water was studied by using surface tension measurements. The critical micellar concentration (CMC) was determined at 25°C, 32°C and 40°C and thermodynamic parameters such as the free energy of micellization (∆G°mic), enthalpy (∆H°mic), and entropy (∆S°mic) of micellization were measured. The CMC at 25°C was 4.93 x 10-5 M and the corresponding values of the thermodynamic parameters were: ∆G°mic = -5.87 kcal/mol; ∆H°mic = -1.12 kcal/mol and ∆S°mic = +16.00 e.u. Micelles of the surfactant DLDMAB act as catalysts for the alkaline hydrolysis of p-nitrophenyl diphenyl phosphate (NPDPP) with a maximum catalytic factor of approximately 120 compared to 80 for CTAB. Typical activation parameters measured for 1.00 x 10-3 M surfactant and 0.005 M NaOH were: Ea = 9.7 kcal/mo/; ∆H°≠ = 9.1 kcal/mol; ∆G°≠ = 19.6 kcal/mol and ∆S°≠ = -33.9 e.u. The kinetic results were also analyzed in terms of the pseudo-phase ion-exchange models (PPIE) and showed that the model is applicable to describe the experimental results.

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