Novel dinuclear dimethylamido-3,5-dimethylpyrazolato and tetranuclear dimethylamido-3,5-dimethylpyrazolato-polyoxo zirconium(iv) complexes. Synthesis and structural characterisation

Abstract

The dinuclear dimethylamido-tris(3,5-dimethylpyrazolato)-zirconium(IV) complex [Zr(3,5-Me2Pz)3(NMe2)]2 1 is prepared by treatment of [Zr(NMe2)4] with 3 equivalents of 3,5-dimethylpyrazole (3,5-Me2PzH) with elimination of dimethylamine. When [Zr(NMe2)4] reacted with 2 equivalents of 3,5-Me2PzH, the bis(dimethylamido)-bis(3,5-dimethylpyrazolato)zirconium(IV) compound [Zr(3,5-Me2Pz)2(NMe2)2]2 2 is obtained. Hydrolysis of [Zr(3,5-Me2Pz)3(NMe2)]2 in wet toluene affords the tetranuclear oxo compound [Zr4(eta2-3,5-Me2Pz)4(NMe2)2(mu3-O)2(mu2-3,5-Me2Pz)4(mu2-NMe2)2] . All synthesised compounds are characterised by NMR spectroscopic and analytical methods. Single crystal X-ray diffraction analysis has established the molecular structures of 1 and 4.

Coordination Versatility of Pyrazole‐Based Ligands towards High‐Nuclearity Transition‐Metal and Rare‐Earth Clusters

“…Molecular structure of [Eu 4 (L1m) 8 ]. [86] Tet-ranuclear heterobimetallic compounds with palladium(II) ions and silver(I) or gold(I) ions have also been reported, [52,87] as well as those with zinc(II) and sodium(I) ions. In these compounds, the pyrazolate anion bridges two dinuclear units.…”

“…Another example is the compound [Cu 4 F 2 (μ 4 ‐F)(L1j) 5 (HL1j) 4 ], which contains a μ 4 ‐F bridge between the four copper(II) ions that interact antiferromagnetically 85. A tetranuclear zirconium(IV) compound is obtained by conversion of a dinuclear compound in wet toluene 86. Tetranuclear heterobimetallic compounds with palladium(II) ions and silver(I) or gold(I) ions have also been reported,52,87 as well as those with zinc(II) and sodium(I) ions 88.…”

Ligand Exchange Reactions of a Monomeric Zirconium Carbonate Complex with Carboxylic Acids Studied by Extended X-ray Absorption Fine Structure, UV Absorption and Raman Spectrophotometry

“…For instance, they rarely exhibit any striking catalytic properties in aqueous solution, but they do exhibit polyoxometalate formation on their own or with other metallic elements. 6,7 This chemical inactivity can be associated with the corrosion resistance zirconiumcontaining materials, and provides other beneficial uses, such as a cross-linking agents for organic backbones to assemble metalorganic frameworks. 8,9 Zirconium salts are also employed in industrial uses, especially for cross-linking of polyvinyl alcohol (PVA).…”