The number of charges and/or organic ligands covalently attached to the surface of CdTe quantum dot nanoparticles has been determined from their electrophoretic mobilities measured in capillaries filled with free electrolyte buffers. Three sizes of water soluble CdTe quantum dots with 3-mercaptopropionic and thioglycolic acids as surface ligands were prepared. Their electrophoretic mobilities in different pH and ionic strength values of separation buffers were measured by capillary electrophoresis with laser induced fluorescence detection. The ζ-potentials determined from electrophoretic mobilities using analytical solution of Henry function proposed by Ohshima were in the range from -30 to -100 mV. Charges of QDs were calculated from ζ-potentials. As a result, numbers of organic ligands bonded to QDs surface were determined to be 13, 14, and 15 for the sizes of 3.1, 3.5, and 3.9 nm, respectively. The dissociation constants of organic ligands bonded on QDs surfaces estimated from the dependence of QDs charge on pH of the separation buffer were 7.8 and 7.9 for 3-mercaptopropionic acid and 6.9 for thioglycolic acid.
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http://dx.doi.org/10.1002/elps.201400459 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
University of California Riverside, Chemistry Department, Chemistry Department, 92521, Riverside, UNITED STATES OF AMERICA.
Although metal-organic frameworks are coordination-driven assemblies, the structural prediction and design using metal-ligand interactions can be unreliable due to other competing interactions. Leveraging non-coordination interactions to develop porous assemblies could enable new materials and applications. Here, we use a multi-module MOF system to explore important and pervasive impact of ligand-ligand interactions on metal-ligand as well as ligand-ligand co-assembly process.
View Article and Find Full Text PDFSmall
January 2025
Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, School of Chemistry and Materials Science, Jiangsu Normal, University Xuzhou, Jiangsu, 221116, P. R. China.
Fabricating visible-light-responsive metal-organic frameworks (MOFs) with high stability and effective catalytic functionality remains a long-term pursuit yet a great challenge. Herein, a strategy of increasing ligand and cluster connectivity is developed to construct highly stable fluorescein MOFs, La-CFL, presenting a new (4,8)-connected topological structure compared to Cd-FL constructed using 6-connected dinuclear clusters and 3-connected tritopic ligands. La(CFL) containers like Chinese "Ritual Wine Vessels (Jue)" resemble linear arrangements interconnected by the [La(COO)] clusters.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
Achieving microecological balance is a complex environmental challenge. This is because the equilibrium of microecological systems necessitates both the eradication of harmful microorganisms and preservation of the beneficial ones. Conventional materials predominantly target the elimination of pathogenic microorganisms and often neglect the protection of advantageous microbial species.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Abteilung für Molekulare Physikalische Chemie, Clausius-Institut für Physikalische und Theoretische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Wegelerstraße 12, 53115 Bonn, Germany.
The binding of carbon dioxide to a transition metal is a complex phenomenon that involves a major redistribution of electron density between the metal center and the triatomic ligand. The chemical reduction of the ligand reveals itself unambiguously by an angular distortion of the CO-molecule as a result of the occupation of an anti-bonding π-orbital and a shift of its antisymmetric stretching vibration, ν, to lower wavenumbers. Here, we generate a carbon dioxide complex of the heavier group-10 metal, platinum, by ultrafast electronic excitation and cleavage of CO from the photolabile oxalate precursor, oxaliplatin, and monitored the ensuing primary dynamics with ultrafast mid-infrared spectroscopy.
View Article and Find Full Text PDFTransition metal-mediated catalytic reduction, oxidation, and hydrofunctionalization reactions are important organic reactions and are considered highly atom-economical. Owing to their unique properties, selenium ligated several transition metals-based complexes have been reported for several catalytic applications. This review presents the synthesis of various selenium-supported transition metal complexes and their catalytic applications in reduction, oxidation, N-alkylation of amines, and hydrofunctionalization reactions.
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