The formation of the ternary complexes CuEDTA(en)(2-), CuEDTA(CN)(3-), CuDCTA(CN)(3-), NiDCTA(CN)(3-) and NiEDTA(en)(2-) has been established spectrophotometrically. The stability constants found were log K = 2.87 +/- 0.03, 3.76 +/- 0.06, 2.64 +/- 0.35, 2.41 +/- 0.21 and 2.74 +/- 0.35 respectively. For the system CuDCTA(2-) + en no ternary complex was observed, instead Cu(en)(2)(2+) was formed. No reaction was found for the systems CoEDTA(2-) + N(3)(-), CoDCTA(2-) + N(3)(-), NiDCTA(2-) + en, NiDCTA(2-) + phen, NiEDTA(2-) + phen, NiDCTA(2-) + N(3)(-), NiEDTA(2-) + N(3)(-), CrEDTA(-) + NH(3), CrEDTA(-) + CN(-), CuEDTA(2-) + N(3) and CuEDTA(2-) + N(3)(-). The systems CoEDTA(2-) + en and CoDCTA(2-) + en involve more than one equilibrium. The absorption spectra of the ternary complexes between 500 and 850 nm are reported.
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http://dx.doi.org/10.1016/0039-9140(83)80003-4 | DOI Listing |
Environ Sci Technol
January 2025
Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
Glyphosate (PMG) is a globally used broad-spectrum herbicide and receives environmental concerns because of its moderate persistence and potential carcinogenicity. Traditional PMG treatment methods often suffer from the generation of a more toxic and persistent aminomethylphosphonic acid (AMPA) intermediate. Herein, we develop a green method with ferrihydrite (FH) and CaO (FH/CaO) via regulating the coordination of PMG with FH and Ca, where the phosphonate group of PMG preferentially binds to FH and its carboxylate side complexes with Ca released by CaO, forming a FH-PMG-Ca ternary surface complex.
View Article and Find Full Text PDFJ Med Chem
January 2025
College of Pharmacy, Chongqing Medical University, Chongqing 400016, China.
Linker structures are a crucial component of proteolysis-targeting chimeras (PROTACs) and have traditionally been designed based on empirical methods, which presents significant challenges in the development of PROTACs. Current optimization strategies typically focus on reducing the number of rotatable bonds in the linker to limit conformational freedom. However, this approach overlooks the complexity of the target protein degradation process.
View Article and Find Full Text PDFJ Biol Chem
January 2025
Department of Chemistry, The University of Texas at San Antonio, Texas 78249, United States. Electronic address:
MarE, a heme-dependent enzyme, catalyzes a unique 2-oxindole-forming monooxygenation reaction from tryptophan metabolites. To elucidate its enzyme-substrate interaction mode, we present the first X-ray crystal structures of MarE in complex with its prime substrate, (2S,3S)-β-methyl-L-tryptophan and cyanide at 1.89 Å resolution as well as a truncated yet catalytically active version in complex with the substrate at 2.
View Article and Find Full Text PDFJ Contam Hydrol
January 2025
Mines Paris, PSL University, Center for Geosciences and Geoengineering, France; ORANO Mining, Environmental R&D Dpt., France.
Sandstone-hosted uranium is mined in the Sahel regions of Niger. The Teloua aquifer is located beneath the ore-processing facilities of one such former mine, COMINAK. The pores of the sandstone bedrock are partially filled by tosudite, a clay with sorption capacities.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China.
The photochemistry of nitrous acid (HONO) plays a crucial role in atmospheric chemistry as it serves as a key source of hydroxyl radicals (OH) in the atmosphere; however, our comprehension of the underlying mechanism for the photochemistry of HONO especially in the presence of water is far from being complete as the transient intermediates in the photoreactions have not been observed. Herein, we report the photochemistry of microsolvated HONO by water in a cryogenic N matrix. Specifically, the 1:1 hydrogen-bonded water complex of HONO was facially prepared in the matrix through stepwise photolytic O oxidation of the water complex of imidogen (NH-HO) via the intermediacy of the elusive water complex of peroxyl isomer HNOO.
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