Zinc Substitution of Cobalt in Vitaminâ
B12 : Zincobyric acid and Zincobalamin as Luminescent Structural B12 -Mimics.
Angew Chem Int Ed Engl
; 58(41): 14568-14572, 2019 10 07.
Article
em En
| MEDLINE
| ID: mdl-31420932
Replacing the central cobalt ion of vitamin B12 by other metals has been a long-held aspiration within the B12 -field. Herein, we describe the synthesis from hydrogenobyric acid of zincobyric acid (Znby) and zincobalamin (Znbl), the Zn-analogues of the natural cobalt-corrins cobyric acid and vitaminâ
B12 , respectively. The solution structures of Znby and Znbl were studied by NMR-spectroscopy. Single crystals of Znby were produced, providing the first X-ray crystallographic structure of a zinc corrin. The structures of Znby and of computationally generated Znbl were found to resemble the corresponding CoII -corrins, making such Zn-corrins potentially useful for investigations of B12 -dependent processes. The singlet excited state of Znby had a short life-time, limited by rapid intersystem crossing to the triplet state. Znby allowed the unprecedented observation of a corrin triplet (ET =190â
kJ mol-1 ) and was found to be an excellent photo-sensitizer for 1 O2 (ΦΔ =0.70).
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vitamina B 12
/
Zinco
/
Cobalto
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2019
Tipo de documento:
Article