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Niobium pentoxide is the inorganic compound with the formula Nb 2 O 5. A colorless, insoluble, and fairly unreactive solid, it is the most widespread precursor for other compounds and materials containing niobium. It is predominantly used in alloying, with other specialized applications in capacitors, optical glasses, and the production of ...
Niobium oxide, archaically called columbium oxide, [1] may refer to: Niobium monoxide (niobium(II) oxide), NbO; Niobium dioxide (niobium(IV) oxide), NbO 2; Niobium pentoxide (niobium(V) oxide), Nb 2 O 5; In addition to the above, other distinct oxides exist general formula Nb 3n+1 O 8n−2 where n ranges from 5 - 8 inclusive, e.g. Nb 8 O 19 (Nb ...
Niobium forms oxides in the oxidation states +5 (Nb 2 O 5), [77] +4 (NbO 2), and the rarer oxidation state, +2 . [78] Most common is the pentoxide, precursor to almost all niobium compounds and alloys. [61] [79] Niobates are generated by dissolving the pentoxide in basic hydroxide solutions or by melting it in alkali metal oxides.
The niobate can be obtained by reacting niobium pentoxide with the corresponding oxide, hydroxide or carbonate. [1] For example, reacting lithium carbonate with niobium pentoxide would obtain lithium niobate: [2] Li 2 CO 3 + Nb 2 O 5 → 2 LiNbO 3 + CO 2 ↑. Cobalt metaniobate can be obtained by heating a mixture of cobalt monoxide and niobium ...
Vanadium(V) oxide or vanadium pentoxide is the most common, being precursor to most alloys and compounds of vanadium, and is also a widely used industrial catalyst. [29] Niobium forms oxides in the oxidation states +5 (Nb 2 O 5), [30] +4 (NbO 2), and the rarer oxidation state, +2 . [31]
Ferroniobium is an important iron-niobium alloy, with a niobium content of 60-70%. [1] It is the main source for niobium alloying of HSLA steel and covers more than 80% of the worldwide niobium production. The niobium is mined from pyrochlore deposits and is subsequently transformed into the niobium pentoxide Nb 2 O 5.
Niobium(V) can form complexes with hydroxy acids, as well as oxalic acid. The salt formed is more complex than tartaric acid for niobium (as opposed to tantalum). [3] NH 4 [NbO(C 2 O 4) 2 (H 2 O) 2]·3H 2 O starts to lose water at 125°C, and at 630°C, it fully decomposes, forming a compound known as niobium pentoxide; [4] Heating this complex and sodium citrate at 650°C can form sodium ...
A prominent early synthetic application of organoniobium chemistry was the use of dimethoxyethane niobium trichloride, NbCl 3 (DME), as a reagent for the reductive coupling of imines with carbonyl compounds to form amino alcohols. [9] This reagent has found further use in other pinacol-type reductive couplings. [10] [8]