Five-co-ordinate magnesium complexes: synthesis and structure of quadridentate Schiff-base derivatives

Abstract

Reaction of dibenzylmagnesium in tetrahydrofuran (thf) with the quadridentate Schiff-base ligands NN'-ethylenebis (acetylacetoneimine) (H,acen), (H,salen),

Group IV Coordination Chemistry of a Tetradentate Redox‐Active Ligand in Two Oxidation States

“…Whereas salen-type ligands typically form six-coordinate complexes with titanium(IV), [13] seven-coordinate complexes are often observed for complexes of the larger metals zirconium and hafnium. [14] In the [N 2 O 2 ] ligand platform, the formation of three five-membered chelates upon metal coordination results in access to seven-coordinate geometries for all three metal ions. In the case of zirconium derivatives 2 and 5, these seven-coordinate species are fluxional on the NMR timescale.…”

Asymmetric Baeyer—Villiger oxidation: control of stereoelectronic demand

“…To eliminate the solvent molecule, refluxing in toluene is required (Scheme 24), 23 resulting in the cis β configuration of the complexes.…”

Salen-type zirconium complexes with a labile coordination site and a robust skeleton: crystal structure of [(t-Bu4-salen)ZrCl2(H2O)]

“…Here, we describe the preparation of [ Treatment of ZrCl 4 and the sodium salt of a substituted salen-type ligand in THF generated a mixture of THF-solvated and unsolvated species [LZrCl 2 (THF) n ] (n ¼ 0,1), which turned to pure unsolvated complexes 1 and 2 when refluxed in toluene. The analogous salen and salphen zirconium complexes in THF-solvated form were previously prepared and structurally characterized by Floriani and co-workers [16] and Repo et al [17]. The H 2 O-solvated complexes [1(H 2 O)] and [2(H 2 O)] were obtained, using either the unsolvated species LZrCl 2 or the mixture obtained from a THF solution, with 1.5 equiv of H 2 O in toluene (Scheme 1).…”