Zinc fluoride

The only reported toxicity data on zinc fluoride in the NIOSH RTECS file is a LD q of 280 mg/kg for subcutaneous adniinistration in frogs. 

Zinc Fluoride Tetrahydrate. Zinc fluoride tetrahydrate [13986-18-0] is prepared by reaction of ZnO and aqueous HF. ZnF2 4H20 has a water solubihty of about 1.6 g/100 mL solution at 25°C. Addition of HF increases the solubihty to 11.8 g/100 mL in a 29% HF solution. The tetrahydrate loses water at temperatures above 75°C. 

One of the most useful ways of introducing fluorine into organic compounds is the placement of the hydroxyl group in alcohols hydroxy compounds, and carboxylic acids Methyl alcohol reacts with anhydrous hydrogen fluoride at 100 500 °C in the presence of aluminum fluoride [60, 61], zinc fluoride [62] chromium fluonde [63], or a mixture of aluminum and chromium fluondes [64] to give a 20-78% yield of fluoromethane Attempted fluorinations of higher alcohols by this method failed [60]... 

Theperfluoroorganozmc compounds have limited application in organic syn thesis because of their lack of reactivity However, heptafluoro I methylethylzinc iodide reacts with acyl fluorides or anhydrides of carboxylic acids in the presence of pyndine to give the corresponding ketones [7S] (equations 28 and 29) In the presence of zinc fluoride, acyl chlorides can be used as substrates [7d]... 

Fluor-wasserstoffaaure, /. hydrofluoric acid, -zink, m. n. zinc fluoride, -zinn, n. tin fluoride. 

Zinc amalgam, 56, 102 Zinc chloride, 56,11 Zinc fluoride, 58, 77... 

In another study, oscillating rheometry was used to examine the effect of adding various simple metal salts to glass-ionomer cements (Crisp, Merson Wilson, 1980). It was found that cement formation for certain glasses which react only slowly with poly(acrylic acid) could be accelerated significantly by certain metal salts, mainly fluorides such as stannous fluoride and zinc fluoride. Some non-reactive glasses could be induced to set by the addition of such compounds. 

The reaction of an a-halo carbonyl compound with zinc, tin, or indium together with an aldehyde in water gave a direct cross-aldol reaction product (Eq. 8.90).226,227 A direct Reformatsky-type reaction occurred when an aromatic aldehyde reacted with an a-bromo ester in water mediated by zinc in low yields. Recently, it was found that such a reaction mediated by indium was successful and was promoted by son-ication (Eq. 8.91).228 The combination of BiCl3-Al,229 CdCl2-Sm,230 and Zn-Et3B-Eb0231 is also an effective mediator. Bismuth metal, upon activation by zinc fluoride, effected the crossed aldol reaction between a-bromo carbonyl compounds and aldehydes in aqueous media. The reaction was found to be regiospecific and syn-diastereoselective (Eq. 8.92).232... 

Zinc fluoride complexes of i-para-toXyX and 3-t-butyl of hydrotris(3-R-5-methylpyrazol-l-yl) borato zinc complexes have been synthesized via complex formation in the presence of potassium fluoride. Facile substitution of the fluoride yields the zinc pyridyl, diethyl ether, or hydride derivatives.241... 

A number of zinc halide complexes, including bridging halides, have already been mentioned in the context of the other ligands systems discussed in this Chapter. Examples will be presented of catalytic systems and solution speciation, particularly in the presence of other coordinating ligands. There are now also a few zinc fluoride species that have been well characterized. 

Fluoride ion selective spectrometry was used to determine the stability constants for zinc fluoride complexes in water at 25 °C, giving values j3i[ZnF(aq)]+ = 3.5 0.1 and /l2[ZnF2(-aq)] = 3.8 0.5.643 These results demonstrate that the complexation of fluoride is very weak and in aqueous chemistry no species beyond ZnF+ is of much importance. Organotitanium fluorides have been used as matrices for trapping molecular ZnF2 and MeZnF. 4... 

Probably the most widely employed technique now used in phase studies is powder X-ray diffraction. The X-ray powder pattern of a compound can be used as a fingerprint, and data for many compounds are available. This can be illustrated with reference to the sodium fluoride (NaF)-zinc fluoride (ZnF2) system. Suppose that pure NaF is mixed with a few percent of pure ZnF2 and the mixture heated at about 600°C until reaction is complete. An X-ray powder photograph will show the presence of two compounds (or phases), NaF, which will be the major component, and a small amount of a new compound (point A, Fig. 4.1a). A repetition of the experiment, with gradually increasing amounts of ZnF2 will yield a similar result, but the amount of the new phase will increase relative to the amount of NaF until... 

In view of the high toxicity of (II), it seemed that the sulphur analogue, dimethylaminosulphonyl fluoride (VI), might be of some interest. We therefore studied the fluorination of dimethylaminosulphonyl chloride. The reaction with potassium fluoride was incomplete, and that with zinc fluoride unsatisfactory, but that with antimony trifluoride using benzene as a solvent proved to be very satisfactory, and an 80 per cent yield of (VI) was obtained. Physiological examination showed that (VI) caused no irritation when small animals were exposed to a concentration of 1 mg./l. for 10 min., and no deaths took place. With the sulphonyl chloride at the same concentration, lacrimation and nasal irritation were caused no deaths were recorded, and all the animals recovered almost immediately on being removed from the chamber. 

Calcium sulfate is formed as a byproduct in industrial processes such as flue gas desulfurization and the production of zinc, fluoride, organic acids and phosphoric acid, in amounts of many million tons per year. In this study the attention is focussed on calcium sulfate from the production of phosphoric acid for fertilizer applications. It is precipitated, from solution after digestion of phosphate ore by addition of sulfuric acid according to [1] ... 

Zinc fluoride is used in the manufacture of phosphors for fluorescent lights. It also is used in electroplating baths, in preservation of wood, in glazes and enamels for ceramics, and in fluorination reactions of organics. 

Anhydrous zinc fluoride is a white hygroscopic solid tetragonal needles density 4.9 g/cm melts at 872°C vaporizes at 1,500°C vapor pressure 1 torr at 1,243°C and 5 torr at 1,328°C practically insoluble in water, 5.2 mg/L sparingly soluble in HCl, HNO3 and ammonia solution. 

Zinc fluoride may be prepared by heating zinc hydroxide or zinc carbonate with hydrogen fluoride ... 

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