Analytical Applications of Crown Compounds and Cryptands

Blasius, E.; Janzen, K.‐P.

doi:10.1007/978-3-642-70108-5_4

Cited by 11 publications

(5 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There has been a considerable interest in the chemistry of crown ethers due to their wide applications. , Most of these applications depend on the complexes formed between crown ethers and different metal cations. Some of the applications of crown ethers are ionophores in membrane transport, column chromatography, disposals of nuclear waste, − and cancer treatment …”

Section: Introductionmentioning

confidence: 99%

“…1,2 Most of these applications depend on the complexes formed between crown ethers and different metal cations. Some of the applications of crown ethers are ionophores in membrane transport, 3 column chromatography, 4 disposals of nuclear waste, [5][6][7][8][9] and cancer treatment. 10 One of the smallest crown ethers is 12c4, which has been the subject of many conformational analysis reports, in the free state [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] and in the complexed form too.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Conformational Study of the Structure of 12-crown-4−Alkali Metal Cation Complexes

El-Azhary

Al-Kahtani

2005

J. Phys. Chem. A

View full text Add to dashboard Cite

A conformational search was performed for the 12-crown-4 (12c4)-alkali metal cation complexes using two different methods, one of them is the CONFLEX method, whereby eight conformations were predicted. Computations were performed for the eight predicted conformations at the HF/6-31+G*, MP2/6-31+G*//HF/6-31+G*, B3LYP/6-31+G*, MP2/6-31+G*//B3LYP/6-31+G*, and MP2/6-31+G* levels. The calculated energies predict a C4 conformation for the 12c4-Na+, -K+, -Rb+, and -Cs+ complexes and a C(s) conformation for the 12c4-Li+ complex to be the lowest energy conformations. For most of the conformations considered, the relative energies, with respect to the C4 conformation, at the MP2/6-31+G*//B3LYP/6-31+G* are overestimated, compared to those at the MP2/6-31+G* level, the highest level of theory considerd in this report, by 0.2 kcal/mol. Larger relative energy differences are attributed to larger differences between the B3LYP and MP2 optimized geomtries. Binding enthalpies (BEs) were calculated at the above-mentioned levels for the eight conformations. The agreement between the calculated and experimental BEs is discussed.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Conformational Study of the Structure of 12-crown-4−Alkali Metal Cation Complexes

El-Azhary

Al-Kahtani

2005

J. Phys. Chem. A

View full text Add to dashboard Cite

show abstract

“…Liner sweep voltammetry may be applied for quantifying more than one electroactive species in a mixture, provided peak potential overlap does not occur. When peak overlap does occur, various schemes including masking , and the use of chemical modified electrodes (CMEs) − may be attempted to suppress the electroactivity of interfering species) at the potential of interest.…”

mentioning

confidence: 99%

Voltammetric Peak Separation of Dopamine from Uric Acid in the Presence of Ascorbic Acid at Greater Than Ambient Solution Temperatures

Zen

Hsu

et al. 2004

Anal. Chem.

View full text Add to dashboard Cite

Peak overlap in voltammetry poses challenges for the quantitative analysis of electroactive species. Dopamine and uric acid are typically challenging to determine voltammetrically because of their very similar oxidation peak potentials. We report preliminary results of the use of a screen-printed carbon electrode for the determination of dopamine and uric acid in an electrolyte solution maintained above ambient temperatures. Higher temperatures resulted in dramatic shifting of the dopamine oxidation peak toward lower potentials, while the uric acid peak was essentially stationary. Ascorbic acid, an interference in voltammetric uric acid determinations, is effectively suppressed at higher temperatures. This resulted in a greater peak separation of dopamine from uric acid at higher temperatures, which is desirable for better peak integration. In addition, greater current responses for both species were recorded at higher temperatures. The cause for such an increase in peak current is unraveled using ac impedance measurements. Presented are preliminary results for determining dopamine and uric acid at temperatures higher than ambient. Much improved voltammetric peak separation and sensitivity is obtained at these higher temperatures compared to ambient.

show abstract

“…For this purpose, radiochemical methods like ion exchange and solvent extraction are very often used. In the recent years, crown compounds are used as new types of extractants in selective extraction methods [1,2]. Among these compounds, the macrobicyclic ligands, namely the ciyptands, form strong complexes, called cryptates, especially with alkali and alkaline-earth cations which are encapsulated within the central cavity of the cryptand [3].…”

Section: Introductionmentioning

confidence: 99%

Study of Strontium Extraction as a Cryptate Complex for Separation of Element 102 from the Actinides

Hussonnois

Bruchertseifer²,

Contantinescu

et al. 1988

Radiochimica Acta

View full text Add to dashboard Cite

show abstract

Analytical Applications of Crown Compounds and Cryptands

Cited by 11 publications

References 63 publications

Conformational Study of the Structure of 12-crown-4−Alkali Metal Cation Complexes

Conformational Study of the Structure of 12-crown-4−Alkali Metal Cation Complexes

Voltammetric Peak Separation of Dopamine from Uric Acid in the Presence of Ascorbic Acid at Greater Than Ambient Solution Temperatures

Study of Strontium Extraction as a Cryptate Complex for Separation of Element 102 from the Actinides

Contact Info

Product

Resources

About