Synthesis of the [MeAl(2-py)₃]^- Anion and Its Application as a Stable and Mild Pyridyl-Transfer Reagent (2-py = 2-Pyridyl)

Abstract

The thermally stable tris(pyridyl) Al(III) complex [MeAl(2-py)3Li·THF] (1·THF), obtained from the reaction of lithiopyridine [2-pyLi] with MeAlCl2 (3:1 molar equiv, respectively), functions as a pyridyl-transfer reagent, as exemplified by the reaction of 1·THF with CuCl (1:1 molar equiv), which gives the Cu(I) organometallic [{Cu(2-py)}3]∞ (2). The solid-state structures of 1, the dimer [MeAl(2-py)3Li]2 ([1]2), and 2 are reported. Complex 2, which cannot be obtained by direct reaction of [2-pyLi] with CuCl, has a polymeric structure in which macrocyclic [Cu(2-py)]3 ring units form infinite offset stacks associated by short Cu···Cu interactions between three- and four-coordinate Cu(I) centers (2.762(3) Å).

Steric Effects on the Structures, Reactivity, and Coordination Chemistry of Tris(2‐pyridyl)aluminates

“…In contrast to the behaviour of the dimeric unsubstituted complex [MeAl(2‐py) 3 Li] 2 ,6a no evidence for a monomer/dimer equilibrium is detected in solution for desolvated 1 . Room‐temperature 1 H and 7 Li NMR spectroscopic studies in [D 8 ]toluene show the presence of a single compound in solution, with no variation in the spectra observed on changing the concentration.…”

“…The extreme steric congestion of the aluminate ion is witnessed in the solid‐state structure of 1 ⋅THF, which has a highly distorted Li–THF coordination environment. In light of this apparently weak coordination of THF to Li + , we decided in our preliminary studies to explore the desolvation of 1 ⋅THF, anticipating the formation of a dimeric complex [ 1 ] 2 , which would be analogous to the dimeric complex [MeAl(2‐py) 3 Li] 2 formed by desolvation of THF using the unsubstituted complex [MeAl(2‐py) 3 Li⋅THF] (Scheme ) 6a…”

Cyclic trinuclear copper(i), silver(i), and gold(i) complexes: a theoretical insight

“…The calculated structural parameters are in good agreement with the available X-ray data. 3,19,25,27,28 For instance, for 1c, the calculated Au + -N and Au + -Au + bond distances and the N-Au + -N bond angle values are 2.002 Å, 3.360 Å, and 179.7°, the correspondent experimental values are 2.003 Å, 3.387 Å, and 177.0°, respectively. Excellent agreement between calculated and experimental structural parameters is also observed in 3a, 3c, 7c, and 8c (Fig.…”

“…26 It has also been shown that CTCs containing the same ligands but with different metal ions such as Cu + , Ag + , or Au + differ not only in their structural parameters, but also in their electronic structure. 28 Fackler and coworkers have synthesized and determined the crystallographic structures of complexes like [Au 3 (μ-3,5-Ph 2 pz) 3 ], [Ag 3 (μ-3,5-Ph 2 pz) 3 ], and [Cu 3 (μ-3,5-Ph 2 pz) 3 ], 29,30 showing that the gold complex exhibits a planar structure, while silver and copper complexes show significant deviation from planarity as well as different metal-ligand bond lengths, Au-N bonds are slightly shorter than Ag-N and Cu-N. Another important feature of CTCs is the amplified π-acidity and π-basicity that they present. [1][2][3]6,[12][13][14][15] The π-acid/ base properties are responsible for the formation of the supramolecular extended stacks with arenes.…”

Postfunctionalization of Tris(pyridyl) Aluminate Ligands: Chirality, Coordination, and Supramolecular Chemistry

“…[5b] We have been particularly interested in aluminates 3 ] À ;F igure 1 B)a s they are unusual in this area in having an overall negative charge( rather than being neutral). [3a] As one of the few anionic members of the tris(pyridyl) family,t hey exhibit as tronga ffinity for metal cations and have extensive coordination chemistry with ab road range of transition metals, [6] main-group metals, [7] and lanthanides. [8] The closely related tris (2-pyridyl)borates [3b, 9] have also attracted recent interest, stemmingf rom their potential applications in polymer and supramolecular chemistry.…”