Title: Chromyl Fluoride
CAS Registry Number: 7788-96-7
CAS Name: Difluorodioxochromium
Additional Names: chromium oxyfluoride
Molecular Formula: CrF2O2
Molecular Weight: 121.99
Percent Composition: Cr 42.62%, F 31.15%, O 26.23%
Line Formula: CrO2F2
Literature References: Prepn of impure product from CrO2Cl2 and F2: von Wartenberg, Z. Anorg. Allg. Chem. 247, 140 (1941). Prepn from CrO3 and SeF4: Bartlett, Robinson, J. Chem. Soc. 1961, 3549; from K2Cr2O7 and HF or from Cr, KNO3 and HF: Wiechert, Z. Anorg. Allg. Chem. 261, 315 (1950). Review of earlier prepns and prepn from CrO3 and ClF, COF2, MoF6 or WF6: P. J. Green, G. L. Gard, Inorg. Chem. 16, 1243 (1977). Review of chromium halides: Fergusson in Halogen Chemistry vol. 3, V. Gutmann, Ed. (Academic Press, New York, 1967) pp 227-302.
Properties: Red-violet to black rhombic or monoclinic crystals; described as a gas or a liq in earlier work with impure samples. Sublimation temp 29.6°; mp 31.6° (885 mm). Extremely reactive; etches glass, quartz. Ignites hydrocarbons such as methane or butane at elevated temps; mixtures burn with a bright flame producing fumes of Cr2O3 and CrF3. Can be stored in a sealed aluminum phosphate glass tube or in a Kel-F tube. Stable indefinitely at room temp in the dark. Polymerizes slowly if exposed to visible, ultraviolet or infrared light to a gray-white solid, mp 200°.
Melting point: mp 31.6° (885 mm); mp 200°
Use: Fluorination catalyst; to increase olefin-polymer receptivity for dyes.