Advances in chelator design are the cornerstone for the development of metals like copper and gallium based biomedical agents and radiopharmaceuticals. To develop optimal chelating ligands, we explored the synthesis and chelating properties of azaheterocycle pendant armed 1,4,7-triazacyclononane (TACN) dimethylcarboxylate derivatives and dimethylphosphonate derivatives. In the complexation kinetics test, dicarboxylate pendant armed TACN derivatives 2,2'-(7-((1H-imidazol-2-yl)methyl)-1,4,7-triazonane-1,4-diyl)diacetic acid (NODA-Im), 2,2'-(7-((1-methyl-1H-imidazol-2-yl)methyl)-1,4,7-triazonane-1,4-diyl)diacetic acid (NODA-MeIm), and 2,2'-(7-(thiazol-2-ylmethyl)-1,4,7-triazonane-1,4-diyl)diacetic acid (NODA-Thia) exhibited fast complexation kinetics towards Cu (II) cations, which were comparable to the frequently explored ligand 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA). And the diphosphonate pendant armed TACN derivative ((7-(thiazol-2-ylmethyl)-1,4,7-triazonane-1,4-diyl)bis(methylene))bis(phosphonic acid) (NODP-Thia) bound with Ga (III) cations at a much faster rate than NOTA. Density functional theory studies confirmed that the better complexation kinetics and metal chelating efficiency of NODA-Im, NODA-MeIm, NODA-Thia, and NODP-Thia could be ascribed to the lower Gibbs energies of corresponding chelator-metal complexes than NOTA-metal complexes. The kinetic inertness of the Cu (II) complex with NODA-Im, NODA-MeIm, and NODA-Thia was also demonstrated by cyclic voltammetry studies. Subsequently radiolabeling experiment demonstrated that these metal chelators could efficiently labeled with Cu or Ga in good radiochemical purities. These preliminary findings support NODA-Im, NODA-MeIm, NODA-Thia, and NODP-Thia as promising leading chelating agents for the development of bifunctional Cu and Ga chelators in biomedical applications.
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http://dx.doi.org/10.1016/j.jinorgbio.2022.111719 | DOI Listing |
Angew Chem Int Ed Engl
August 2024
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China.
A novel class of thienyltriazine triamides (TTTAs) was facile synthesized and firstly used as cathode interlayers (CILs) for organic solar cells (OSCs). By utilizing different aromatic arms and pendant polar groups, their optoelectronic properties and aggregation behaviors were effectively modulated. The combination of thienyltriazine (TT) core, naphthylamide arm and imidazole pendant group endows TT-N-M with suitable energy levels, intensified work function tunability, higher conductivity, and well-balanced crystallinity and film-forming ability, boosting both the performance and stability of OSCs significantly.
View Article and Find Full Text PDFMed J Armed Forces India
December 2022
Associate Professor (Pediatric Surgery), Maulana Azad Medical College, MAMC Campus, New Delhi, India.
Magnetic foreign body ingestion poses a threat especially if more than one is ingested. If consumed alone, small magnetic foreign bodies are likely to pass without significant event; however, when multiple magnets are ingested, they can be attracted to each other through the intestinal wall, which may lead to serious consequences and complications, including bowel perforation, obstruction, peritonitis, and death. We report a case of a 2-years male child patient presented with multiple small round magnetic beads ingestion from a magnetic pendant that appeared like a necklace pearl after conglomeration on abdominal radiograph.
View Article and Find Full Text PDFChem Biol Interact
March 2023
Post-Graduate and Research Department of Chemistry, The New College (Autonomous), University of Madras, Chennai, 600 014, India. Electronic address:
A series of pendant-armed mixed-ligand copper(II) complexes of the type [CuL(diimine)] (1-6) have been synthesized by the reaction of pendant-armed ligands N,N-bis(2-(((E)-2-hydroxy-5-methylbenzylidene)amino)ethyl)benzamide (HL), N,N-bis(2-(((E)-2-hydroxy-5-methylbenzylidene)amino)ethyl)-4-nitrobenzamide (HL) and N,N-bis(2-(((E)-2-hydroxy-5-methylbenzylidene)amino)ethyl)-3,5-dinitrobenzamide (HL) with diimine = 2,2'-bipyridyl (bpy) or 1,10-phenanthroline (phen) in the presence of copper(II) chloride and analyzed using various spectroscopic methods. All the spectroscopic results support that the complexes adopt a pentagonal-bipyramidal shape around the copper ion. Gram-positive and Gram-negative bacteria were used to test all the complexes for antibacterial activity and all the complexes had greater potency against gram-negative pathogens.
View Article and Find Full Text PDFMolecules
December 2022
Department of Chemistry and Physics, Southwestern Oklahoma State University, Weatherford, OK 73096, USA.
Ethylene cross-bridged tetraazamacrocycles are known to produce kinetically stable transition metal complexes that can act as robust oxidation catalysts under harsh aqueous conditions. We have synthesized ligand analogs with single acetate pendant arms that act as pentadentate ligands to Mn, Fe, Co, Ni, Cu, and Zn. These complexes have been synthesized and characterized, including the structural characterization of four Co and Cu complexes.
View Article and Find Full Text PDFInorg Chem
December 2022
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, Jiangsu Province, P. R. China.
The first-row transition-metal ions Mn-Cu could serve as effective templates to construct three types of double-[1 + 1], [2 + 2], and [1 + 1] Schiff-base dinuclear macrocyclic complexes in the presence of dialdehydes with different pendant arms and a common 1,8-diamine. The extremely flexible nature of macrocyclic ligands allows for the multiple template-directed syntheses, but the final products could be finely tuned by the subtle variations of Mn-Cu ions in a 3d-electronic configuration, radius, and coordination number/geometry as well as the auxiliary (pendant-armed and anionic) template effect at the same time. Two borderlines are observed at the Co ion for forming double-[1 + 1] and [2 + 2] metallacycles involving the Hpdd precursor and the [1 + 1] Cu complex for double-[1 + 1] and [2 + 2] macrocycles containing the Hhpdd unit, respectively.
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