Metal complexes of 1-oxa-4,7,10-triazacyclododecane-N,N',N''-triacetic acid.
The macrocyclic complexone 1-oxa-4,7,10-triazacyclododecane-N,N',N''-triacetic acid (cODTA) has been synthesized and its protona constants, stability constants of metal complexes and enthalpy changes for the formation of alkaline-earth complexes have been determined. Although it is not so powerful a complexing agent as the N-acetate derivative of the corresponding tetra-aza macrocycle, cDOTA, this is still one of the strongest complexones known, particularly towards the alkaline-earth metals. The complexes of the transition metals are also very stable and there is an inversion of the Irving-Williams order of stability for the complexes of cobalt and nickel.
Amorim
M T
MT
Centro de Quimica Estrutural, Instituto Superior Técnico, Lisbon, Portugal.
Delgado
R
R
da Silva
J J
JJ
Cândida
M
M
Vaz
T A
TA
Vilhena
M F
MF