Synthesis and characterization of poly(pyrazolyl)borate tantalum amide complexes and their reactivities toward oxygen

Abstract

5) has been synthesized by a similar procedure through the reaction of 1 with TpK [Tp = tris(pyrazolyl)borohydride].Reactions of 3 and 5 with oxygen were also studied. 2, 4, and 5 were characterized by NMR, EA, and single-crystal X-ray diffraction.polypyrazolyborate, tantalum, amide, oxygen

Synthesis and DFT, Multinuclear Magnetic Resonance, and X-ray Structural Studies of Iminoacyl Imido Hydridotris(3,5-dimethylpyrazolyl)borate Niobium and Tantalum(V) Complexes

“…Therefore, preliminary reports in this field pointed to facile in situ decomposition of the compounds via hydrolysis and redox reactions, B–N bond cleavage, or unexpected synthesis of ionic derivatives. However, despite these difficulties, a number of group 4 and 5 metal complexes of the [MTpX 3 ] − and [MTpX 4 ] , types, respectively, with sterically crowded and electronically flexible Tp ligands have been synthesized and their reactivity toward cationic species potentially useful in polymerization processes has been studied. In this context, we have reported the synthesis and structural studies of a series of chlorido, amido, and alkyl chlorido imido hydridotris(3,5-dimethylpyrazolyl)borate niobium and tantalum(V) compounds.…”

Hydridotris(3,5-dimethylpyrazolyl)borate Dimethylamido Imido Niobium and Tantalum Complexes: Synthesis, Reactivity, Fluxional Behavior, and C–H Activation of the NMe2 Function

“…In group 5, the formation of new niobium and tantalum complexes bearing tris(pyrazolyl)borate ligands in moderate to high yields was highly dependent on experimental details (solvent, temperature) and byproduct formation precluded their use as accessible starting materials . However, several classes of monoanionic hydrido(trispyrazolyl)borate niobium and tantalum complexes containing halide, alkoxide, alkyl, imido, oxo, and alkyne ancillary ligands have been prepared. − …”