Premium
Zinc Substitution of Cobalt in Vitamin B 12 : Zincobyric acid and Zincobalamin as Luminescent Structural B 12 ‐Mimics
Author(s) -
Kieninger Christoph,
Baker Joseph A.,
Podewitz Maren,
Wurst Klaus,
Jockusch Steffen,
Lawrence Andrew D.,
Deery Evelyne,
Gruber Karl,
Liedl Klaus R.,
Warren Martin J.,
Kräutler Bernhard
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201908428
Subject(s) - corrin , cobalt , zinc , singlet state , chemistry , triplet state , excited state , crystallography , coordination sphere , intersystem crossing , inorganic chemistry , crystal structure , molecule , organic chemistry , physics , atomic physics
Replacing the central cobalt ion of vitamin B 12 by other metals has been a long‐held aspiration within the B 12 ‐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 vitamin B 12 , 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 Co II ‐corrins, making such Zn‐corrins potentially useful for investigations of B 12 ‐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 ( E T =190 kJ mol −1 ) and was found to be an excellent photo‐sensitizer for 1 O 2 (Φ Δ =0.70).