Niobium complexes arsenic donors

Although trialkyl- and triarylbismuthines are much weaker donors than the corresponding phosphoms, arsenic, and antimony compounds, they have nevertheless been employed to a considerable extent as ligands in transition metal complexes. The metals coordinated to the bismuth in these complexes include chromium (72—77), cobalt (78,79), iridium (80), iron (77,81,82), manganese (83,84), molybdenum (72,75—77,85—89), nickel (75,79,90,91), niobium (92), rhodium (93,94), silver (95—97), tungsten (72,75—77,87,89), uranium (98), and vanadium (99). The coordination compounds formed from tertiary bismuthines are less stable than those formed from tertiary phosphines, arsines, or stibines. 

Numerous adducts of MX4 with nitrogen, phosphorus, arsenic, oxygen and sulfur donors have been obtained, mainly for niobium with X = CI or Br7 (Tables 29-33). The absence of MF4 adducts, except for [NbF4(py)2],511 may be due less to their instability than to a lack of investigations. An ill-defined fluoro trichloride complex, [NbCl3F(MeCN)2.65], has also been reported.512... 

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See also in sourсe #XX -- [ , ]

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