A new chelating ligand, 2-(2-(5-tert-butylisoxazol-3-yl)hydrazono)-N-(2,4-dimethylphenyl)-3-oxobutanamide (HL), and its four binuclear transition metal complexes, M(2)(L)(2) (micro-OCH(3))(2) [M=Ni(II), Co(II), Cu(II), Zn(II)], were synthesized using the procedure of diazotization, coupling and metallization. Their structures were postulated based on elemental analysis, (1)H NMR, MALDI-MS, FT-IR spectra and UV-vis electronic absorption spectra. Smooth films of these complexes on K9 glass substrates were prepared using the spin-coating method and their absorption properties were evaluated. The thermal properties of the metal(II) complexes were investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC). Different thermodynamic and kinetic parameters namely activation energy (E*), enthalpy of activation (DeltaH*), entropy of activation (DeltaS*) and free energy change of activation (DeltaG*) are calculated using Coats-Redfern (CR) equation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.saa.2007.01.006 | DOI Listing |
ACS Catal
November 2024
Department of Chemistry and Biochemistry, University of Arkansas, 345 North Campus Walk, Fayetteville, Arkansas 72701, United States.
Natural glycoside hydrolases are distinguished by their ability to hydrolyze glycosidic bonds with high efficiency and selectivity. This feature is achieved through specific interactions in the active site during catalytic turnover and is not just facilitated by two catalytically active amino acids. Intrigued by these features, a biomimetic α-galactosidase mimic was developed using an empirical catalyst design.
View Article and Find Full Text PDFDalton Trans
January 2025
Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia.
Four new metal-organic frameworks with the formulae [Sm(phen)(NO)(chdc)]·2solv, where solv = ,-dimethylformamide (DMF; 1), ,-dimethylacetamide (DMA; 2), ,-diethylformamide (DEF; 3), -formylpiperidine (NFP; 4), phen = 1,10-phenanthroline and chdc = -1,4-cyclohexanedicarboxylate were synthesized and structurally characterized. These compounds are based on similar binuclear samarium(III)-carboxylate blocks, bound by flexible chdc linkers into layered -type coordination networks. The amide solvents drive different intralayer block orientations between 1 and 2-4 and different layer-to-layer packings in all the described compounds.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Hubei Key Laboratory for Precision Synthesis of Small Molecule Pharmaceuticals, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China. Electronic address:
Transition metal complexes has been explored in the treatment of tumors in photodynamic theray (PDT) or photothermal therapy (PTT) and Osmium complex attracts attentration due to its lower toxicity and longer absorption wavelength. However, there was no report about binuclear Os complex for combined therapy of PDT and PTT which could have a synergistic effect and improve the effectiveness. Herein, we synthesis of mono/dinuclear Os complexes (OsY1, OsY2) with dual PDT/PTT capabilities under a single near-infrared (NIR) excitation wavelength.
View Article and Find Full Text PDFChem Asian J
January 2025
Department of Chemistry, Indian Institute of Technology Indore, Khandwa Road, Indore, 453552, Madhya Pradesh, India.
A series of N,O donor-based mono- and binuclear four-coordinated boron complexes were synthesized. Depending on the substitution and spacer, these complexes exhibit intense blue, green and yellow emission in solution states. Notably, the fluorescence quantum yields (Φ) and fluorescence decay (lifetime, τ) of mononuclear boron complexes (2 a-2 e) were higher than the binuclear boron complexes (2 f-2 k).
View Article and Find Full Text PDFDalton Trans
November 2024
Departamento de Química Inorgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
Two yellow-to-orange-emitting binuclear iridium complexes of the form [Ir(ppy)(N^N)](ClO) (namely IrL1 and IrL2) were designed and synthesized, using phenylpyridine (ppy) as a cyclometalating ligand (C^N) and phenanthroimidazole-based bridging compounds as ancillary ligands (N^N), to explore the effect of sterically hindered bulky bridging ligands and their substituents on the electronic and emission properties of the related ionic transition metal complexes (iTMCs) and the performance of iTMC-based light-emitting electrochemical cells (iTMC-LECs). In CHCl solution, complexes IrL1 and IrL2 afford yellow-to-orange emission centered at 570 and 582 nm with PLQYs of 27% and 36%, respectively. The reversible and quasi-reversible redox behaviors of both complexes are shown to reveal the excellent stability of the emitters in solution.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!