The substitution of an acetate pendant arm on the endocyclic or exocyclic nitrogen atoms of AAZTA with a hydroxybenzyl group results in two regioisomeric Gd(III)complexes with different hydration numbers,thermodynamic...The substitution of an acetate pendant arm on the endocyclic or exocyclic nitrogen atoms of AAZTA with a hydroxybenzyl group results in two regioisomeric Gd(III)complexes with different hydration numbers,thermodynamic stabilities differing by 5.5 log K units and remarkably different kinetic inertness.The ligand functionalized with the phenol group on the exocyclic N atom(AAZ3A-exoHB)forms a Gd(III)complex with remarkably high stability(log K_(GdL)=25.06)thanks to the tight coordination of the phenol group,which presents a rather low protonation constant(log K_(GdHL)=3.22).展开更多
文摘The substitution of an acetate pendant arm on the endocyclic or exocyclic nitrogen atoms of AAZTA with a hydroxybenzyl group results in two regioisomeric Gd(III)complexes with different hydration numbers,thermodynamic stabilities differing by 5.5 log K units and remarkably different kinetic inertness.The ligand functionalized with the phenol group on the exocyclic N atom(AAZ3A-exoHB)forms a Gd(III)complex with remarkably high stability(log K_(GdL)=25.06)thanks to the tight coordination of the phenol group,which presents a rather low protonation constant(log K_(GdHL)=3.22).
