Vanadium phosphide

Some phosphides, such as titanium phosphide [12037-65-9] TiP, can be prepared bypassing phosphine over the metal or its haUde. Reaction of phosphine with heavy metal salt solutions often yields phosphines that may contain unsubstituted hydrogens. Phosphides may also be prepared by reducing phosphoms-containing salts with hydrogen, carbon, etc, at high temperatures, the main example of which is the by-product formation of ferrophosphoms in the electric furnace process for elemental phosphoms. Phosphoms-rich phosphides such as vanadium diphosphide [12037-77-3] may be converted to lower phosphides, eg, vanadium phosphide [12066-53-4] by thermal treatment. 

Vanadium phosphides are synthesized from the purest V metal available and P. 

The vanadium phosphide VP can be obtained not only via the above synthesis, but also by thermal degradation of VP3 at 700-900°C (vacuum). 

Alternate method Electrolysis of V3O5-containing phosphate melts, with cathodic reduction to vanadium phosphides [M. Chene, Comptes Rendus Hebd. Seances Acad. Sci. 2W, 1144 (1939) Ann. chimie [11], 15, 272 (1941)]. 

These are usually reactions of anhydrous transition and B metal halides with dry alkali metal salts such as the sulphides, nitrides, phosphides, arsenides etc. to give exchange of anions. They tend to be very exothermic with higher valence halides and are frequently initiated by mild warming or grinding. Metathesis is described as a controlled explosion. Mixtures considered in the specific reference above include lithium nitride with tantalum pentachloride, titanium tetrachloride and vanadium tetrachloride, also barium nitride with manganese II iodide, the last reaction photographically illustrated. 

Ignition or explosive reaction with metals (e.g., aluminum, antimony powder, bismuth powder, brass, calcium powder, copper, germanium, iron, manganese, potassium, tin, vanadium powder). Reaction with some metals requires moist CI2 or heat. Ignites with diethyl zinc (on contact), polyisobutylene (at 130°), metal acetylides, metal carbides, metal hydrides (e.g., potassium hydride, sodium hydride, copper hydride), metal phosphides (e.g., copper(II) phosphide), methane + oxygen, hydrazine, hydroxylamine, calcium nitride, nonmetals (e.g., boron, active carbon, silicon, phosphoms), nonmetal hydrides (e.g., arsine, phosphine, silane), steel (above 200° or as low as 50° when impurities are present), sulfides (e.g., arsenic disulfide, boron trisulfide, mercuric sulfide), trialkyl boranes. 

Volume III Halides, Hydroxides, Oxides. (1997) ISBN 0-9622097-2-4 (descriptions of 628 mineral species, including antimonates, antimonites, arsenites, carbides, halides, hydroxides, nitrides, oxides, phosphides, silicides, vanadium oxysalts). 

Write the chemical formula for each substance mentioned in the following word descriptions (use the front inside cover to find the s5mbols for the elements you don t know), (a) Zinc carbonate can be heated to form zinc oxide and carbon dioxide, (b) On treatment with hydrofluoric acid, silicon dioxide forms silicon tetrafluoride and water, (c) Sulfur dioxide reacts with water to form sulfurous acid, (d) The substance hydrogen phosphide, commonly called phosphine, is a toxic gas. (e) Perchloric add reacts with cadmium to form cadmium(II) perchlorate. (f) Vanadium(in) bromide is a colored solid. 

The black powder consists of almost insoluble phosphides. This simple method seems to have very little to do with the discovery of vanadium. Sefstrom s use of the method and his ability for critical analysis, however, was of decisive significance. 

---