A ‘double reciprocal’ analysis of calorimetric data for simultaneous determination of equilibrium constants and enthalpies of complex formation: intermolecular hydrogen bonding in peroxy acid–oxygen base complexes in carbon tetrachloride

Author(s):  
Jože Škerjanc ◽  
Aleksander Regent ◽  
Božo Plesničar
2010 ◽  
Vol 75 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Branislav Jovic ◽  
Aleksandar Nikolic ◽  
Erna Davidovic ◽  
Slobodan Petrovic

This paper reports the results of an FT-IR and NIR study of N-methylformamide in carbon tetrachloride solution in presence of ethers as the O-electron donors, i.e., diethyl ether (DEE), diisopropyl ether (DiPE), methyl t- -butyl ether (MtBE), dibutyl ether (DBE), dipentyl ether (DPE), tetrahydrofuran (THF) and tetrahydropyran (THP). The spectroscopic characteristics of the N-H???O hydrogen bonded complexes are given. In addition, the equilibrium constants for 1:1 complex formation were determined at 25?C using Mid-IR and NIR measurements.


1974 ◽  
Vol 52 (4) ◽  
pp. 653-660 ◽  
Author(s):  
Earl M. Woolley ◽  
Dennis S. Rushforth

The intermolecular hydrogen-bonding self-association of the three cresols in CCl4 solutions at 25 °C has been investigated by calorimetric means. Calorimetrically determined heats of dilution of each of the cresols in anhydrous CCl4 are interpreted in terms of two different models: (i) dimerization and trimerization self-association reactions, and (ii) dimerization followed by stepwise polymerization self-association reactions. Values of K, ΔH0, and ΔS0 for these reactions are calculated using least-squares and other methods. Results show that o-cresol is clearly less associated in anhydrous CCl4 solution at 25 °C than either m- or p-cresol. Values of K2 and K3 (both based on molar concentrations of solutes) and ΔH20and ΔH30 (kcal) for the reactions [Formula: see text] respectively, are o-cresol: 0.7, 1.3,−3.4,−12.5; m-cresol: 0.8, 5.0,−5.0,−13.6; p-cresol: 0.35, 6.5,−5.5,−13.4. Values of K2 and Ks (both based on molar concentrations of solutes) and ΔH20 and ΔHs0 (kcal) for the reactions [Formula: see text] (all n > 2 with same Ks and ΔHS0), respectively, are o-cresol: 0.7, 1.6, −4.2, −4.5; m-cresol: 1.2, 4.0, −5.0, −4.3; p-cresol: 1.0, 7.0, −3.3, −3.5.


2000 ◽  
Vol 57 (1) ◽  
pp. o58-o60
Author(s):  
Sean P. Bew ◽  
Mark E. Light ◽  
Michael B. Hursthouse ◽  
David W. Knight ◽  
Robert J. Middleton

The crystal structure determination of the title compound, C13H15IO4, has allowed the relative stereochemistry between the tetrasubstituted C atoms on the tetrahydrofuran moiety to be confirmed. The title compound is a precursor of the ionophoric antibiotic Aplasmomycin. The compound is involved in both intra- and intermolecular hydrogen bonding, the latter link the molecules into chains running along thebaxis.


1978 ◽  
Vol 56 (23) ◽  
pp. 2959-2965 ◽  
Author(s):  
J. Korppi-Tommola ◽  
H. F. Shurvell

Complex formation between pentachlorophenol and acetone and acetone-d6 in carbon tetrachloride solution has been studied in both the hydroxyl and carbonyl stretching regions of the infrared spectrum. Factor analysis of the digitized spectra indicates three absorbing components for each set of solutions in the hydroxyl stretching region. Concentration studies revealed roughly linear relationships between the areas of the 'free' ν(OH) band and both of the resolved complex bands, suggesting that two different 1:1 complexes occur in CCl4 solution. In the ν(CO) region only one band due to complex formation was detected. Equilibrium constants for the isotopically different complexes at about 30 °C are reported. In the hydroxyl stretching region, band resolution was also carried out using four components which gave a better fit to the observed spectrum. A set of equilibrium constants were then obtained. However, considerable difficulties were met in the calculations and in the interpretation of these results, so that the three band, two complex model is preferred.


2019 ◽  
Vol 107 (7) ◽  
pp. 623-634
Author(s):  
Aleksandr N. Vasiliev ◽  
Nidhu L. Banik ◽  
Rémi Marsac ◽  
Stepan N. Kalmykov ◽  
Christian M. Marquardt

Abstract Natural clay rocks like Opalinus (OPA) and Callovo-Oxfordian (COx) clay rock are considered as potential host rocks for deep geological disposal of nuclear waste. However, small organic molecules such as propionate and lactate exist in clay rock pore water and might enhance Np mobility through a complexation process. Therefore, reliable complex formation data are required in the frame of the Safety Case for a nuclear waste repository. A solvent extraction technique was applied for the determination of ${\rm{NpO}}_2^ + $ complexation with propionate and lactate. Extraction was conducted from isoamyl alcohol solution containing 10−3 M TTA and 5 · 10−4 M 1,10-phenanthroline. Experiments were performed in 0.5–2.6 m NaCl solutions at temperatures ranging from 22 to 60 °C. Formation of 1:1 Np(V) complexes for propionate and lactate was found under the studied conditions. The SIT approach was applied to calculate equilibrium constants β°(T) at zero ionic strength from the experimental data. Log β°(T) is found linearly correlated to 1/T for propionate and lactate, evidencing that heat capacity change is near 0. Molal reaction enthalpy and entropy ( ${\Delta _{\rm{r}}}H_{\rm{m}}^ \circ $ and ${\Delta _{\rm{r}}}S_{\rm{m}}^ \circ $ ) could therefore be derived from the integrated van’t Hoff equation. Data for log β° (298.15 K) are in agreement with literature values for propionate and lactate. Np(V) speciation was calculated for concentrations of acetate, propionate and lactate measured in clay pore waters of COx. In addition, the two site protolysis non-electrostatic surface complexation and cation exchange (2SPNE SC/CE) model was applied to quantitatively describe the influence of Np(V) complexation on its uptake on Na-illite, a relevant clay mineral of OPA and COx.


1985 ◽  
Vol 63 (12) ◽  
pp. 3367-3370 ◽  
Author(s):  
Pierre Ménassa ◽  
Camille Sandorfy

The interaction of the inverted micelles of AOT (sodium di(2-ethylhexyl)sulfosuccinate) with different alcohols due to hydrogen bonding has been studied by means of infrared spectroscopy. Spectra of solutions of the alcohols with increasing concentrations of AOT showed a decrease in the intensity of the free OH stretching band. At the same time a new OH band due to a H-bonded alcohol-inverted micelle complex appears and its intensity increases as the intensity of the free band decreases. Calculated values of the equilibrium constants for the formation of the complexes n-alcohol–AOT, showed a decrease in alcohol–AOT association with the increase of the length of the aliphatic chains in the n-alcohols. Surprisingly, cholesterol behaved like a short chain while other cyclic alcohols like long chain alcohols.


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