Wydział Chemii

Tomasz Ruman

Zbigniew Ciunik

Stanisław Wołowiec

2003

European Journal of Inorganic Chemistry

89-93

10.1002/ejic.200390017

Naukowa

Angielski

Artykuł

The synthesis of hydrotris(pyrazol-1-yl)borate ligands (Tp^x) by condensation of sodium borohydride with 3(5)-isopropylpyrazole and either 5(3)-methyl-3(5)-phenylpyrazole or 3,5-diphenylpyrazole gave the novel heteroscorpionate ligands hydrobis(5-methyl-3-phenylpyrazolyl)(5-isopropylpyrazolyl)borate and hydrobis(3,5-diphenylpyrazolyl)(5-isopropylpyrazolyl)borate, respectively. These were converted into CoTp^x(NCS) complexes as well as CoTp^x₂ in the case of the former ligand. In an attempted synthesis of heteroscorpionates bearing two y-isopropylpyrazolyl moieties (y = 3 or 5) formation of the homoscorpionate hydrotris(3-isopropylpyrazolyl)borate along with the above-mentioned heteroscorpionates was noticed; no formation of the desired heteroscorpionates could be detected. The bis[hydrobis(5-methyl-3-phenylpyrazolyl)(5-isopropylpyrazolyl)borato]cobalt(II) and tetrahydrofuranothiocyanatobis[hydrobis(5-methyl-3phenylpyrazolyl)(5-isopropylpyrazolyl)borato]cobalt(II) tetrahydrofuran solvate complexes were studied by X-ray crystallography. Two Tp^x ligands provide six nitrogen donors from pyrazol-1-yl residues to form a Tp^x₂Co complex in which two 5-isopropylpyrazolyl rings are placed in a plane of symmetry, whereas the same Tp^x ligand is bound in an η³ fashion in the pentacoordinate [CoTp^x(NCS)(THF)]·THF complex, in which a nitrogen atom from thiocyanate and an oxygen atom from THF complete the coordination sphere of the central metal ion. These compounds as well as the complexes thiocyanatohydrobis(3,5-diphenylpyrazolyl)(5-isopropylpyrazolyl)boratocobalt(II) and thiocyanatohydrotris(3-isopropylpyrazolyl)boratocobalt(II) were characterized by ¹H NMR and IR spectroscopy.

https://doi.org/10.1002/ejic.200390017

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