A New Micro-Calorimeter: the Heats of Dilution of Aqueous Solutions of Sucrose at 20 and 30° and their Heat Capacities at 25°

Gucker, Frank T.; Pickard, Hugh B.; Planck, Ralph W.

doi:10.1021/ja01871a068

Cited by 113 publications

(62 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their accuracy was tested by measuring the dilution enthalpy of a concentrated sucrose solution (0.985 mol/L). The resulting value (−0.643 ± 0.015 kJ/mol) agreed well with the literature value (−0.653 kJ/mol) (13). The sample cell and the reference cell of calorimeter were initially loaded with 0.5 and 0.7 mL of pure water, respectively.…”

Section: Methodssupporting

confidence: 87%

Enthalpies of Micellization of Double Chain and Gemini Cationic Surfactants

Bai

Wang

Yan

et al. 2001

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

Section: Methodssupporting

confidence: 87%

Enthalpies of Micellization of Double Chain and Gemini Cationic Surfactants

Bai

Wang

Yan

et al. 2001

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

“…Prior to use, the instrument was calibrated against an internal heat pulse, and the functional response was verified by determination of the heat of dilution of a concentrated sucrose solution. [42] Data points were collected every 2 s. The reaction heat was determined following 10 automatic injections from a 250 mL injection syringe (containing 2.01 mm of NADH model) into the reaction cell (1.00 mL) containing 10.87 mm N,N,N',N'-tetramethyl-p-phenylenediamine radical cation perchlorate. Injection volumes (10 mL) were delivered at 0.5 s time intervals with 500 s between every two injections.…”

Section: Titrated Calibration Experimentsmentioning

confidence: 99%

Determination of the C4H Bond Dissociation Energies of NADH Models and Their Radical Cations in Acetonitrile

Zhu

et al. 2003

Chemistry A European J

149

134

View full text Add to dashboard Cite

Heterolytic and homolytic bond dissociation energies of the C4-H bonds in ten NADH models (seven 1,4-dihydronicotinamide derivatives, two Hantzsch 1,4-dihydropyridine derivatives, and 9,10-dihydroacridine) and their radical cations in acetonitrile were evaluated by titration calorimetry and electrochemistry, according to the four thermodynamic cycles constructed from the reactions of the NADH models with N,N,N',N'-tetramethyl-p-phenylenediamine radical cation perchlorate in acetonitrile (note: C9-H bond rather than C4-H bond for 9,10-dihydroacridine; however, unless specified, the C9-H bond will be described as a C4-H bond for convenience). The results show that the energetic scales of the heterolytic and homolytic bond dissociation energies of the C4-H bonds cover ranges of 64.2-81.1 and 67.9-73.7 kcal mol(-1) for the neutral NADH models, respectively, and the energetic scales of the heterolytic and homolytic bond dissociation energies of the (C4-H)(.+) bonds cover ranges of 4.1-9.7 and 31.4-43.5 kcal mol(-1) for the radical cations of the NADH models, respectively. Detailed comparison of the two sets of C4-H bond dissociation energies in 1-benzyl-1,4-dihydronicotinamide (BNAH), Hantzsch 1,4-dihydropyridine (HEH), and 9,10-dihydroacridine (AcrH(2)) (as the three most typical NADH models) shows that for BNAH and AcrH(2), the heterolytic C4-H bond dissociation energies are smaller (by 3.62 kcal mol(-1)) and larger (by 7.4 kcal mol(-1)), respectively, than the corresponding homolytic C4-H bond dissociation energy. However, for HEH, the heterolytic C4-H bond dissociation energy (69.3 kcal mol(-1)) is very close to the corresponding homolytic C4-H bond dissociation energy (69.4 kcal mol(-1)). These results suggests that the hydride is released more easily than the corresponding hydrogen atom from BNAH and vice versa for AcrH(2), and that there are two almost equal possibilities for the hydride and the hydrogen atom transfers from HEH. Examination of the two sets of the (C4-H)(.+) bond dissociation energies shows that the homolytic (C4-H)(.+) bond dissociation energies are much larger than the corresponding heterolytic (C4-H)(.+) bond dissociation energies for the ten NADH models by 23.3-34.4 kcal mol(-1); this suggests that if the hydride transfer from the NADH models is initiated by a one-electron transfer, the proton transfer should be more likely to take place than the corresponding hydrogen atom transfer in the second step. In addition, some elusive structural information about the reaction intermediates of the NADH models was obtained by using Hammett-type linear free-energy analysis.

show abstract

“…The enthalpy of dilution ∆ dil H m of aqueous sucrose solutions, extensively studied mainly by Gucker and coworkers [19], is well known over a wide range of molalities and temperatures [7,13,14], and has been used for tests of microcalorimeters where two liquids are mixed. Concentrated sucrose solutions (w = 0.15 to 0.25) are quite viscous and can be difficult to mix with water, especially in flow calorimeters without stirring.…”

Section: Dilution Of Aqueous Sucrose Solutionsmentioning

confidence: 99%

Standards in isothermal microcalorimetry (IUPAC Technical Report)

Wadsö

Goldberg

2001

Pure and Applied Chemistry

317

119

View full text Add to dashboard Cite

The main calorimetric principles used in isothermal microcalorimetry are briefly discussed. Different chemical calibration and test reactions are discussed, with a focus on reactions suitable for ambient conditions: reactions initiated by mixing of liquids (including titration microcalorimetry), dissolution of solid compounds and of slightly soluble gases, a photochemical process, and thermal power signals released over an extended period of time. Guidelines on the use of standardized chemical test and calibration reactions in isothermal microcalorimetry are presented. A standardized terminology in reporting characteristics of isothermal microcalorimeters is proposed.

show abstract

A New Micro-Calorimeter: the Heats of Dilution of Aqueous Solutions of Sucrose at 20 and 30° and their Heat Capacities at 25°

Cited by 113 publications

References 0 publications

Enthalpies of Micellization of Double Chain and Gemini Cationic Surfactants

Enthalpies of Micellization of Double Chain and Gemini Cationic Surfactants

Determination of the C4H Bond Dissociation Energies of NADH Models and Their Radical Cations in Acetonitrile

Standards in isothermal microcalorimetry (IUPAC Technical Report)

Contact Info

Product

Resources

About