Synthesis of new multidentate ligands for the coordination of indium(iii), gadolinium(iii) and thorium(iv)

Abstract

Efficient syntheses are described for five new multidentate ligands containing 3-hydroxy-6-methyl-2-pyridyl donor groups: 4,7,10-tris(3-hydroxy-6-methyl-2-pyridylmethyl)-1-oxa-4,7, 10-triazacyclododecane, 2; 4,10,13-tris(3-hydroxy-6-methyl-2-pyrildylmethyl)-1,7-dioxa-4,10,13-triazacyclopentadecane, 3; 4,10,16-tris(3-hydroxy-6-methyl-2-pyridylmethyl)-1,7,13-trioxa-4,10,16-triazacyclooctadecane, 4; 1,4,7,10-tetrakis(3-hydroxy-6-methyl-2-pyridylmethyl-1,4,7,10-tetraazacyclododecane, 5; 1,4,8,11 -tetrakis(3-hydroxy-6-methyl-2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane. 2, 3, and 4 are designed for the coordination of In(III) and Gd(III): 5 and 6 are for Th(IV).