Complexes of heteroscorpionate trispyrazolylborate anionic ligands Part II. The X-ray crystallographic and H-1 NMR studies on thiocyanatohydrobis(3-phenylpyrazolyl)(3,5-di-tert-butylpyrazolyl)borato cobalt(II) and thiocyanatohydrobis(3-phenyl,5-me
Synthesis of two heteroscorpionate tris(pyrazolyl)borate anionic ligands (Tp') was described; the sterically demanding hydro-bis(3-phenylpyrazolyl)(3,5-di-tert-butyl obtained by condensation of KBH4 with 3-phenylpyrazole and 3,5-di-tert-butylpyrazole and hydrpbis(3-phenyl,5-methlpyrazolyl)(3-methyl, 5-phenylylpyrazolyl)borate(-) and hydrobis(3-phenyl,5-methylpyrazolyl)(3- 5-phenylylpyrazolyl)borate - formed in similar reaction between NaBH4 and 3(5)-methyl,5(3)-phenylpyrazole. The ligands were converted into tetracoordinate HB(3,5-di-tBupz)(3-Phpz)(2)Co(NCS) and pentacoordinate HB(3-Me,5-Phpz)(3-Ph, 5-Mepz)(2)Co(NCS)(THF) THF complexes, which molecular structures were determined by X-ray crystallographic method. The reactivity of high-spin cobalt(II) complexes was studied by the 'H NMR spectroscopy in solution. The reactive HB(3-Me,5-Phpz)(3-Ph.5-Mepz)(2)Co(NCS) complex readily underwent conversions into pentacoordinate HB(3-Me,5-Phpz)(3-Ph,5-Mepz)(2)Co(OOCCH(OH-OH(3))and hexacoordinate HB(3-Me,5-Phpz)(3-Ph,5-Mepz)(2)CoHB(pz)(3) complexes. (C) 2001 Elsevier Science B.V. All rights reserved. References: 10
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