Niobium, tetrakis stereochemistry

Niobium, tetrakis(2,2,6,6-tetramethyl-3,5-heptanedione)-stereochemistry, 1, 94 structure, 1, 93... 

The stereochemistry of tetrakis (dipivaloylmethanato)niobium(iv) has been shown by X-ray analysis to be the first example of a M(bidentate)4 complex whose stereochemistry is based on an idealized square antiprism (38)." The first Ta pure n.q.r. spectra have been detected in Ta2X o (X = Q or Br) as part of a detailed n.q.r. study of such dimers. ... 

Tetrakis(dipivaloylmethanato)niobium(iv), [Nb (Bu CO)2CH 4] has been prepared by treating NbCl4 with dipivaloylmethane in MeCN containing EtjN. X-Ray crystallographic studies have shown that this compound is the first example of an M(bidentate)4 complex whose stereochemistry is based on an idealized D4 square antiprism (38). In the absence of oxygen and moisture, [Nb (Bu CO)2CH 4] affords stable, very weakly conducting solutions in CH2CI2 which contain the monomer. ... 

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See also in sourсe #XX -- [ ]

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