7788-97-8 Usage
Chemical Properties
Different sources of media describe the Chemical Properties of 7788-97-8 differently. You can refer to the following data:
1. Chromium(III) fluoride [7788-97-8], CrF3, Mr 108.99. The anhydrous compound forms highly refractive rhombohedral crystals. It melts above 1000°C and is distinctly volatile between 1100 and 1200 °C. Chromium(III) fluoride is insoluble in water if no divalent chromium is present. Double compounds are formed with other metal fluorides, e.g., green CrF3 · 2KF·H2O.
Hydrates are known which contain three [16671-27-5] to nine [68374-27-6] molecules of water. The violet hexaaquochromium(III) fluoride, [Cr(H2O)6]F3, and its trihydrate, [Cr(H2O)6]F3 · 3H2O, can be obtained from hexaaquochromium(III) salt solutions and alkali fluorides. Products containing lesswater are green. The composition of the industrial product corresponds approximately to CrF3 · 3.5H2O and the product contains about 30 % chromium.
For the production of chromium(III) fluoride hydrate, chromium(III) oxide hydrate is dissolved in hot aqueous hydrofluoric acid and the green salt crystallizes. Chromium(III) fluoride is used in the textile industry for mordanting wool, for chromating dyestuffs, and in vigoureux printing. Chromium(III) fluorides have also found application in rust-prevention paints as corrosion inhibitors.
2. Green crystalline powder or crystals
Uses
Different sources of media describe the Uses of 7788-97-8 differently. You can refer to the following data:
1. Some important uses are in printing and dyeing woolens; mothproofing of woolen materials; metal polishing; coloring marbles; and as a catalyst in halogenation reactions.
2. Used in the preparation of a mixed-metal fluoride catalyst for synthesis of HFC-134a.
3. Printing and dyeing woolens, moth-proofing,
halogenation catalyst.
Preparation
Chromium(III) fluoride may be prepared by heating chromium trichloride under a stream of hydrogen fluoride:
The compound may be prepared by the reaction of chromium hydroxide with hydrofluoric acid:
Physical properties
Dark green needles (anhydrous salt) or green hexagonal crystals (trihydrate); density 3.8 g/cm3 (anhydrous fluoride), 2.2 g/cm3 (trihydrate); anhydrous salt melts at 1,100°C and sublimes above this temperature; practically insoluble in water and ethanol (anhydrous salt); trihydrate sparingly soluble in water; soluble in HCl forming a violet solution.
General Description
Chromic fluoride solution is a green crystalline solid dissolved in water. CHROMIUM(III) FLUORIDE is corrosive to metals and tissue.
Air & Water Reactions
Water soluble.
Reactivity Profile
Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas.
Hazard
Irritant to skin and eyes, especially in solution.
Health Hazard
TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Fire Hazard
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.
Flammability and Explosibility
Notclassified
Safety Profile
A poison by ingestion.
A corrosive. When heated to decomposition
it emits toxic vapors of Cr and F-.
Check Digit Verification of cas no
The CAS Registry Mumber 7788-97-8 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,7,8 and 8 respectively; the second part has 2 digits, 9 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 7788-97:
(6*7)+(5*7)+(4*8)+(3*8)+(2*9)+(1*7)=158
158 % 10 = 8
So 7788-97-8 is a valid CAS Registry Number.
InChI:InChI=1/Cr.3FH/h;3*1H/q+2;;;/p-3
7788-97-8Relevant articles and documents
Synthesis of a porous chromium fluoride catalyst with a large surface area
Quan, Heng-Dao,Yang, Hui-E,Tamura, Masanori,Sekiya, Akira
, p. 254 - 257 (2005)
A novel approach to the preparation of a porous chromium fluoride catalyst with a large surface area is reported. The pores were generated by introduction of a siliceous material into the precursor of the catalyst and then removal of the material by reaction with anhydrous hydrogen fluoride. During the reaction, the formation and escape of a volatile gas (SiF4) from the precursor enlarged the surface area of the chromium fluoride. This process provided for the first time a porous chromium fluoride with a surface area of 187 m 2/g and a pore volume of 0.58 cm3/g. Furthermore, the porous chromium fluoride exhibited excellent chemical stability in the presence of HCl, HF, and F2. It was catalytically active for halogen exchange in a fixed-bed fluorination reaction, and it exhibited excellent catalytic performance in mitigating the coke formation on the surface of the catalyst during vapor-phase catalytic fluorination.
Chromium oxide trifluoride (CrOF3). Preparation and properties
Green,Johnson,Loehr,Gard
, p. 3562 - 3565 (1982)
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Structural and magnetochemical studies of Ba5Mn3F19 and related compounds AII5MIII3F19
Dahlke,Graulich,Welsch,Pebler,Babel
, p. 1255 - 1263 (2008/10/08)
Single crystal structure determinations by X-ray methods were performed at the following compounds, crystallizing tetragonally body-centred (Z = 4): Sr5V3F19 (a = 1423.4(2), c = 728.9(1) pm), Sr5Cr3F19 (a = 1423.5(2), c = 728.1(1) pm), Ba5Mn3F19 (a =1468.9(1), c =770.3(1) pm, Ba5Fe3F19 (a =1483.5(1), c =766.7 (1) pm), and Ba5Ga3F19 (a = 1466.0(2), c = 760.1(2) pm). Only Ba5Mn3F19 was refined in space group I4cm (mean distances for elongated octahedra Mn1-F: 185/207pm equatorial/axial; for compressed octahedra Mn2-F: 199/182 pm), the remaining compounds in space group I4/m. In all cases the octahedral ligand spheres of the M1 atoms showed disorder, the [M1F6] octahedra being connected into chains in one part of the compounds and into dimers in the other. The magnetic properties of the V, Cr and Mn compounds named above and of Pb5Mn3F19 and Sr5Fe3F19 as well were studied; the results are discussed in context with the in part problematic structures.
