A folded [2 × 2] metallo-supramolecular grid from a bis-tridentate (1,2,3-triazol-4-yl)-picolinamide (tzpa) ligand

Abstract

A flexible ditopic ligand 1 containing two N,N,O-tridentate (1,2,3-triazol-4-yl)-picolinamide chelating pockets is reported and the formation of multimetallic architectures is explored in the solid and the solution phase. The self-assembled Zn complex [Zn(1)](ClO) exhibited a folded [2 × 2] square grid supramolecular architecture that selectively assembled in MeCN solution as shown using various spectroscopic techniques. The closely related Fe complex shows equivalent behaviour in the solid state, while a discrete dinuclear species [Cu(NO)1]·5MeCN was the sole product observed in the solid state from the reaction between 1 and Cu under similar conditions.

Synthesis of α-amino acid derived (1,2,3-triazol-4-yl)-picolinamide (tzpa) ligands and their corresponding luminescent Tb(iii) complexes

“…1. 20,21 The tzpa family are designed by combining two effective ligand motifs, namely 2,3-bis(1,2,3-triazol-4-yl)picolinamide ( btp ) and dipicolinic acid/amide ( dpa ), both of which we have synthesized and employed in our studies over the years. 22,23 Here, we present the synthesis of two chiral tzpa ligands (shown as 4 and 5 in Scheme 1) from L-amino acids (as protected esters), and investigate their interactions with the lanthanide ion Tb( iii ) by probing their ground and excited state properties in solution.…”

Formation of lanthanide luminescent di-metallic helicates in solution using a bis-tridentate (1,2,3-triazol-4-yl)-picolinamide (tzpa) ligand

“…23 With that in mind we recently combined these two coordination environments within a single ligand motif, the result being the formation of a new class of bis-tridentate (1,2,3-triazol-4-yl)picolinamide (tzpa) ligands. [24][25][26] Up until now, our effort has focused on exploring some of the coordination chemistry of the tzpa ligands with d-metal ions, which included the formation of chiral tetranuclear Cu(II) supramolecular assembly (M 4 L 4 ) grids, using 1 (Figure 1). 26 However, no evidence for the formation of circular helicates was observed in the solid state using either Cu(II) or Fe(II) with tzpa ligands.…”