Alkali metal fluoroborates

Alkali metal fluorides and ammonium bifluorides, fluoroborates, fluorophosphates, fluoroarsenates, fluoroantimonates, fluorotitanates, fluorozirconates, etc. require either anhydrous HF or aqueous HF for their preparations. Similarly, alkaline earth metals, transition metals, rare earth metal fluorides or their fluorosalts require... 

Metal fluoroborates are produced either from fluoroboric acid and metal salts or by reactions of boric acid and hydrofluoric acid with metal salts. Fluoroborates of alkali metals and ammonium ions tend to crystallize as hydrates and are water soluble except for those of potassium, rubidium, and cesium. The major use for these compounds is as a high-temperature flux. Transition metal and other heavy metal fluoroborates are not as well known and well characterized. They are usually prepared from fluoroboric acid and an appropriate salt and are sold as 40-50% water solutions. Some fluoroborates from metals such as tin, lead, copper, and nickel are prepared by electrolysis of fluoroboric acid. The transition and other heavy metal fluoroborate solutions are used primarily as plating solutions and catalysts. 

Alkali, ammonium and transition metal fluoroborates can be produced from the acid. These fluoroborates are utilized as fluxes in the galvanic deposition of metals, as flame retardants etc. 

OSMOSOL EXTRA (71-23-8) Forms explosive mixture with air (flash point 59°F/ 15°C). Violent reaction with strong oxidizers, potassium-tert-butoxide, triethylaluminum. Reacts, possibly violently, with acetaldehyde, alkalineearth and alkali metals, strong acids, strong caustics, aliphatic amines, benzoyl peroxide, chromic acid, chromium trioxide, dialkylzincs, dichlorine oxide, ethylene oxide, hypochlorous acid, isocyanates, isopropyl chlorocarbonate, lithium tetrahydroaluminate, nitric acid, nitrogen dioxide, nitronium tetra-fluoroborate(l-), pentafluoroguanidine, phosphorus pentasulfide, tangerine oil, triisobutyla-luminum. Attacks some plastics, rubber, and coatings. 

For polyurethane foams, solid dicarboxylic acids such as fumaric, isophthalic or chlorendic acids are supplemented with sulphur, while alkali metal and ammonium fluoroborates (KBF4, NH4BF4) were patented as smoke suppressants for poly-isocyanurates. ... 

Alkali metal fluorides ZrF4- containing BeF2" containing ThF4- containing Fluoroborates... 

In this method " - the melt eontains boric oxide and the metal oxide in a suitable electrolyte, usually an alkali or alkaline-earth halide or fluoroborate. The cell is operated at 700-1000 C depending on electrolyte composition. To limit corrosion, the container serving as cathode is made of mild steel or of the metal whose boride is sought. The anode is graphite or Fe. Numerous borides are prepared in this way, e.g., alkaline-earth and rare-earth hexaborides " and transition-metal borides, e.g, TiBj NijB, NiB and TaB... 

In another category of template synthesis, ethylene oxide is cyclized in the presence of BF3 and alkali, alkaline earth, or transition ions as their fluoroborate, fluorophosphate or fluoroantimonate salts - see [4.4], This procedure yields cyclic tetramers, pentamers and/or hexamers with the particular product(s) obtained being quite dependent on the metal present. Thus Ca(BF4)2 gives a 50% yield of tetramer, Cu(BF4)2 and Zn(BF4)2 give the pentamer in 90% yield, whereas Rb(BF4) and Cs(BF4) yield exclusively hexamer (Dale Daasvatn, 1976). 

LEAD FLUOROBORATE (13814-96-5) Pb (BF4)2 Decomposes in water or acids, forming ionic lead and fluoboric acid solution. Aqueous solution incompatible with sulfuric acid, alkalis, ammonia, aliphatic amines, alkanolamines, alkylene oxides, amides, epichlorohydrin, organic anhydrides, isocyanates, nitromethane, vinyl acetate. Corrodes aluminum and most other metals. Thermal decomposition releases lead fumes and hydrogen fluoride gas. On small fires. 

Solid salts of tetrafluoroboric acid are readily isolated, those of NH4 and many metals such as the alkalis and alkaline earths being commercially available. Ammonium fluoroborate may be prepared in a dry way by fusing NH4HF2 with B203. B(OH)3 also readily dissolves in HF to form solutions of fluoroboric acid ... 

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