Homoleptic complexes niobium

Niobium (continued) complexes, 6 5 with bipy and phen, 12 179 homoleptic, 2,2 -bipyridine, 34 14 compounds... 

Besides the phosphoranes, the homoleptic amides of niobium(V) and tantalum(V) are the only pentamides known.1 These compounds, exemplified by M(NMe2)5 (M = Nb, Ta) are volatile, hydrocarbon-soluble solids.37 All physical and spectroscopic data are consistent with a strictly mononuclear existence for these complexes. 

No homoleptic isocyanide complexes of niobium, tantalum, titanium, zirconium, and halfnium have yet been synthesized. The vanadium cation... 

A recent review gives a chronological survey of the syntheses and characterizations of homoleptic mononuclear metal-carbonyl (see Carbonyl Complexes of the Transition Metals) anions. [M(CO)6] is a key precursor to niobium and tantalum carbonyls. More reliable synthesis of [Ta(CO)6] ... 

The first tris(arene) niobium complex, [Nb(l-4-jj -anthracene)3], prepared by the Na or K anthracene reduction of NbCl4(THF)2, undergoes facile anthracene displacement in the presence of CO to afford [K(18-crown-6)(THF)2][Nb(CO)6]. Reduction of TaCls by sodium naphthalene provides [Na(THF)][Ta(jj -naphthalene)3], the first homoleptic naphthalene complex of a third row transition metal. This complex reacts with CO and anthracene to give [Ta(CO)e] and [Ta(l-4-jj -anthracene)3], respectively. The latter product reacts with cyclooctatetraene (COT) to give [Ta(COT)3]-.==i= ... 

Carmalt CJ, Dinnage CW, Parkin IP, et al. (2002) Synthesis of a homoleptic niobium(v) thiolate complex and the preparation of niobium sulfide via thio sol-gel and vapor phase thin-film experiments. Inorg Chem 41 3668-3672... 

The tetranuclear [La (OC2H4)3N 2 Nb(OPr )4 3] contains eight-coordinated (bicapped trigonal antiprism) La and distorted octahedral niobium (Fig. 4.62). ° A homoleptic trinuclear lanthanum niobium complex [(Pr 0)3Nb(/t-OPr )3La(OPr )(/t-OPr )2Nb(OPr )4] has also been established. The distorted octahedral La is triple-bridged to one Nb and double-bridged to the other, generating a bent (136.2°) NbLaNb axis." ... 

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