Oxide Trichloride

Molybdenum oxide trichloride has been prepared by heating molybdenum(VI) oxide or molybdenum dioxide dichloride with molybdenum(V) chloride. Molybdenum(VI) oxide tetrachloride is a by-product of the latter reaction.1 It was also prepared by the sealed-tube reaction of liquid sulfur dioxide with molybdenum (Y) chloride2 and by the thermal decomposition of molybdenum oxide tetrachloride in a stream of nitrogen. In the following procedure, it is prepared by reducing molybdenum oxide tetrachloride with refluxing chlorobenzene.4 

In all the following operations, an atmosphere of prepurified nitrogen must be maintained throughout the reaction, and all glassware must be flame-dried or oven-dried and purged with nitrogen to remove traces of moisture. Transferals of molyb- 

The method to be described is a significant modification of the synthesis outlined by Hurd and Brimm2 and is derived from the apparatus of Geilmann and Wrigge.6 This procedure allows for the decomposition of large quantities of rhenium(V) chloride in a short period (approximately an hour for a 14-g. sample), in high yield (of the order of 90%) and by an inexperienced person. 

The apparatus illustrated in Fig. 19 is utilized for the synthesis of nonachlorotrirhenium(III). The bulbs are constructed from 

J Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Mass. 02139. 

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Vanadium oxide trichloride, VOCI3, vanadyl chloride. Readily prepared yellow liquid, b.p. 127 C, formed CK plus heated V2OS plus C. Readily hydrolysed by water. 

Another method of purifying niobium is by distillation of the anhydrous mixed chlorides (29). Niobium and tantalum pentachlorides boil within about 15°C of one another which makes control of the process difficult. Additionally, process materials must withstand the corrosion effects of the chloride. The system must be kept meticulously anhydrous and air-free to avoid plugging resulting from the formation of niobium oxide trichloride, NbOQ. Distillation has been used commercially in the past. 

Niobium Pent chloride. Niobium pentachloride can be prepared in a variety of ways but most easily by direct chlorination of niobium metal. The reaction takes place at 300—350°C. Chlorination of a niobium pentoxide—carbon mixture also yields the pentachloride however, generally the latter is contaminated with niobium oxide trichloride. The pentachloride is a lemon-yeUow crystalline soHd that melts to a red-orange Hquid and hydrolyzes readily to hydrochloric acid and niobic acid. It is soluble in concentrated hydrochloric and sulfuric acids, sulfur monochloride, and many organic solvents. 

Niobium Oxide Trichloride. Niobium oxide trichloride, NbOCl, also can be prepared in a variety of ways, ie, oxidation of the... 

Octachloro-dimolybdan(II)-Salze2 und Molybdan-oxid-trichlorid/Zink reduzieren in guten Ausbeuten Sulfoxide zu Sulfanen2 (bessere Ausbeuten werden mit Trikalium-nonachloro-diwolframat erzielt) z. B. ... 

Treating the oxide, trichloride, or metal with boron tribromide or boron triiodide has produced tribromides and triiodides for lanthanum (119). Presumably, treating the metal or the oxide with boron trichloride will produce the trichloride. 

The pentachloride also may be made by chlorination of niobium pentoxide in the presence of carbon at 300°C. The products, however, contain small amounts of niobium oxide trichloride, NbOCls. 

Niobium pentoxide reacts with hydrogen chloride gas at 400 to 700°C to form niobium oxide trichloride, NbOCls [13597-20-1] ... 

Pentaoxide also reacts with niobium pentachloride at elevated temperatures, forming the oxide trichloride ... 

Table 5 lists parameters for a selection of halogen-bridged species with this type of asymmetry. The effect of multiply bonded oxygen is larger than the other ligands listed, and the comparison of oxide as part of the ligand, in the pentane-2,4-dionate complex,27 where the asymmetric Mo—Cl distances only differ by 0.091 A, with the oxide trichloride, where the difference is 0.44 A, is particularly striking. 

The impure vanadium (V) oxide is refluxed for 16 hours with an equivalent amount of thionyl chloride (12 ml. SOCI2 per 10 g. 205). The ground joints of the apparatus must be lubricated with silicone grease. A silica gel drying tube is connected to the top of the condenser to exclude moisture. The vanadium (V) oxide trichloride formed is distilled using a Widmer column. (The checkers report obtaining about 50 ml. of VOCI3, b.p. 123.5 to 124° at 737 mm.)... 

Hydrolysis of the oxide trichloride is effected by making successive small additions from a dropping funnel (the deliv-... 

Numerous methods have been described for the preparation of niobium(V) chloride, among them the reaction of niobium(V) oxide with thionyl chloride in a sealed system. In such a procedure some niobium(V) oxide trichloride, NbOCls, is almost always formed, and it is difficult to obtain the pentachloride completely free from this impurity, even by repeated sublimation. The simple, efficient method described here consists in allowing hydrous niobium(V) oxide to react with thionyl chloride at room temperature. Almost quantitative conversion is observed, the pentachloride dissolving in the thionyl chloride, from which it may be recovered, free of oxide trichloride, by vacuum evaporation... 

The stabilization of a novel dinuclear isomer of tellurium tetrachloride was possible by formation of an adduct with phosphorus oxide trichloride, which was prepared from solutions of TeCU in pure POCI3 (171, 172). The adduct molecule is shown in Fig. 17. As the Te-0 distance of 2.73 A shows, the interaction of the novel (TeCl4)2 molecule with the coordinated POCI3 is only weak. Prom vibrational spectra and... 

Niobium(V) oxide trichloride is a significant impurity in niobium(V) chloride, which is used for the preparation of niobium metal. Indeed oxygen impurities in the high-purity niobium produced in this way originate largely with NbOCl 3, and the feasibility of its removal by phosgene treatment has been examined between 380 and 450 C [223,224] ... 

Tungsten(VI) oxide tetrachloride is a common impurity in tungsten(VI) chloride. By anaiogy with niobium(V) oxide trichloride (Section 9.2.2), phosgene might have been expected to convert WOCi to WClj, according to ... 

A process for the commercial production of phosphorus(V) oxide trichloride by treating a pre-heated mixture of wood charcoal with P2O5. HPO3, H P O or H3PO4 has been patented [1915],... 

One method of separating niobium from tantalum is to pass a gaseous mixture of niobium(V) chloride and tantalum(V) chloride over adjacent beds of calcium oxide and calcium fluoride the niobium emerges as volatile niobium(V) oxide trichloride whilst the tantalum is trapped in the CaO and CaFj beds. The reactions postulated to be responsible for trapping tantalum are [1984b] ... 

Technetium oxide trichloride, TCOCI3, was obtained by reaction of technetium dioxide in a chlorine stream at 30f)-35() °C. The brown, slightly volatile product can be sublimed at about. 500 "C in vacuum. TcOCls shows a strong band in the IR at 1017 cm, which can be attributed to the metal-oxygen stretehing mode. Tlie compound is readily hydrolyzed and disproportionates [.30.98.99] ... 

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