An octadentate bis(semicarbazone) macrocycle: a potential chelator for lead and bismuth radiopharmaceuticals.
Dalton Trans
; 49(42): 14962-14974, 2020 Nov 03.
Article
em En
| MEDLINE
| ID: mdl-33079111
ABSTRACT
A variant of 1,4,7,10-tetraazacyclododecane (cyclen) bearing two semicarbazone pendant groups has been prepared. The octadentate ligand forms complexes with Bi3+ and Pb2+. X-ray crystallography showed that the neutral ligand provides an eight-coordinate environment for both metal ions and intermolecular hydrogen bond interactions have influenced the coordination environments of both complexes in the solid state. NMR spectroscopy revealed a fluxional environment for both complexes. The ligand was radiolabeled with the α-emitting radioactive isotope 213Bi3+, which is used in systemic targeted radiotherapy. The resulting complex was stable in serum for at least 90 min (two decay half-lives). The Pb2+ complex has reasonably fast kinetics of formation (t1/2 = 20 min) at 25 °C and pH 7.4. The Bi3+ and Pb2+ complexes show kinetic stability in 1.2 M HCl (half-lives of 214 min and 47 min, respectively). This is the first description of a macrocycle bearing semicarbazone pendant groups and its utility in coordinating main group metals, specifically those with radiotherapeutic potential.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Semicarbazonas
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Bismuto
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Quelantes
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Compostos Radiofarmacêuticos
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Complexos de Coordenação
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Ciclamos
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Chumbo
Idioma:
En
Revista:
Dalton Trans
Assunto da revista:
QUIMICA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Reino Unido