Coordination and Bioinorganic Chemistry of Aryl-Appended Tris(2-Pyridylmethyl)amine Ligands

Abstract

Aryl-appended tris(2-pyridylmethyl)amine ligands are a relatively new class of chelate ligands in coordination and synthetic bioinorganic chemistry. As outlined herein, to date, coordination complexes of such ligands have been prepared and characterized for first row metal ions from groups 7-12. These studies revealed key coordination properties for this family of ligands. Aryl-appended tris(2-pyridylmethyl)amine ligands have been recently employed in synthetic, biologically relevant metal complexes that exhibit: 1) arene hydroxylation reactivity relevant to non-heme iron-containing containing enzymes that hydroxylate aromatic amino acids; and 2) structural and reactivity properties relevant to Ni(II)-containing acireductone dioxygenase, urease, and glyoxalase I enzymes.

Tripodal Tetraamine Ligands Containing Three Pyridine Units: The other Polypyridyl Ligands

“…This review attempts to highlight and summarise systematic studies which quantify these effects. It also complements other reviews on related ligand systems 13,14…”

O2-Dependent Aliphatic Carbon−Carbon Bond Cleavage Reactivity in a Ni(II) Enolate Complex Having a Hydrogen Bond Donor Microenvironment; Comparison with a Hydrophobic Analogue

“…Second, the phenyl-appended pyridyl donors of 6-Ph 2 TPA exhibit more variation in terms of Ni-N distances (~0.12 Å) in response to the presence of different exogenous ligands. This is not surprising in that aryl-appended pyridyl donors of chelate ligands have been shown to fully dissociate from a metal center in response to exogenous ligand coordination 29. Third, the microenvironment of bnpapa-ligated complexes is more compact, as determined by comparison of the distance between the two neopentylamine nitrogen atoms (~5.6 Å) versus that of the ipso carbons of the phenyl appendages of 6-Ph 2 TPA (~6.4 Å).…”

Asymmetry and steric hindrance in tripodal ligands: Reaching the limit for octahedral geometry with the newly synthesized [(6-bromo 2-pyridylmethyl) (6-fluoro 2-pyridylmethyl) (2-pyridylmethyl)] amine tripod in FeCl2 complexes

“…Indeed, it appears that there is an increasing demand for easy-to-prepare small ligands providing upon coordination with transition metals thermally stable complexes. Tetradentate tripods derived from the tris(2-pyridylmethyl)amine (TPA) are among the most thoroughly studied with a broad range of potential applications [3][4][5][6][7]. The introduction of asymmetric centres by substitution at the methylene carbon has been reported for several years, allowing extension of the chemistry of these simple ligands to various areas (asymmetric recognition of amino acids, study of chiropticalor luminescence properties to cite only a few of them) [7][8][9][10][11][12][13].…”