Lanthanide luminescent di-metallic triple-stranded helicates formed from bis-tridentate (1,2,3-triazol-4-yl)-picolinamide (tzpa) ligands and their higher order self-assemblies

Abstract

The bis-tridentate (1,2,3-triazol-4-yl)-picolinamide (tzpa) ligands 1 and 2 were used in the formation of the luminescent di-metallic Tb(III) triple stranded helicates 3 and 4 (L₃Tb₂; L = 1 or 2). Both 3 and 4 were formed in high yield under either kinetic or thermodynamic conditions and their binding constant values were evaluated. The photophysical properties of the assemblies were analysed in the solution and solid state. The morphology of the ligands vs. the Tb(III) assemblies were significantly different as detected by SEM.