Studies on olefin epoxidation with t-BuOOH catalysed by dioxomolybdenum(VI) complexes of a novel chiral pyridyl alcoholate ligand

Synthesis and Structure of a Sodium Complex of an Aromatic β-Diketone and Pyrazolylpyridine

“…For example, endo-bidentate (η 2 ) coordination of pyrazolate ligands has been established for the lanthanides [7]. However, in attempts to prepare an anionic complex of the type [Eu(BTA) 3 …”

“…Most of this work has centred on either high-valent d 0 transition metal complexes, mainly Mo VI , as catalysts for olefin epoxidation [2][3][4][5], or trivalent lanthanide ions for optical applications [1,6]. Ligands derived from 2-(3-pyrazolyl)pyridine (Figure 1) have proven to be particularly interesting for both applications.…”

“…Ligands derived from 2-(3-pyrazolyl)pyridine (Figure 1) have proven to be particularly interesting for both applications. For example, the replacement of the coordinated water molecules in the tris(β-diketonate) complex Eu(NTA) 3 (H 2 O) 2 (NTA = 1-(2-naphthoyl)-3,3,3-trifluoroacetonate) with the ligand ethyl-[3-(2-pyridyl)-1-pyrazolyl]acetate modifies the luminescence properties of the parent triscomplex in a favourable way [6]. In these complexes the pyrazole moiety is in its neutral form and is bidentate, with the metal ion coordinated to the pyridyl nitrogen and the pyrazole nitrogen.…”

“…We have been interested in the coordination behaviour of a broad range of neutral or anionic chelating ligands containing N and/or O donor atoms, such as β-diketones [1], cis-diols [2], oximes [2], 2-pyridyl alcohols [3], diazabutadienes [4] and pyrazolylpyridines [5,6]. Most of this work has centred on either high-valent d 0 transition metal complexes, mainly Mo VI , as catalysts for olefin epoxidation [2][3][4][5], or trivalent lanthanide ions for optical applications [1,6].…”

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Abstract:Reaction of NaH with a THF solution of Eu(BTA) 3 (pypzH) 3,pyridine] leads to the formation of the europium-free tetrasodium complex [Na 4 (pypzH) 2 (µ 4 -BTA) 2 (µ 2 -BTA) 2 ]. Single-crystal Xray diffraction studies revealed the presence of a centrosymmetric Na + hybrid tetramer, which fully occupies the contents of the triclinic unit cell.

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