Di-tert-butyl chromate is an alkoxide with the formula CrO2(OC(CH3)3)2. It is prepared by treatment of t-butanol with chromic anhydride. It forms red crystals at temperatures below –5 °C, above which it melts to give a red oil.[3][4] The complex, which is diamagnetic, is of fundamental interest as a model for the intermediates in oxidations of alcohols by chromium(VI). This complex is stable because as a t-butyl groups lack beta-hydrogens. This complex and its analogues have tetrahedral geometry at chromium, as established by X-ray crystallography of its analogues.[5][6]
Names | |
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IUPAC name
tert-Butyl chromate
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Other names
Di-tert-butyl ester of chromic acid; Bis(tert-butyl)chromate
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Identifiers | |
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3D model (JSmol)
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ChemSpider |
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PubChem CID
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RTECS number |
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Properties | |
[(CH3)3CO]2CrO2 | |
Molar mass | 230.3 g/mol[1] |
Appearance | red oil |
Melting point | −2.8 °C (27.0 °F; 270.3 K)[2] |
Miscible[2] | |
Hazards | |
NIOSH (US health exposure limits): | |
PEL (Permissible)
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TWA 0.005 mg CrO3/m3 [skin][1] |
REL (Recommended)
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Ca TWA 0.001 mg Cr(VI)/m3[1] |
IDLH (Immediate danger)
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Ca [15 mg/m3 {as Cr(VI)}][1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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It is used as a precursor to chromium-based catalysts, such as the Phillips catalyst, which are employed for the polymerization of ethylene.[7]
Like other forms of hexavalent chromium, di-tert-butyl chromate is classified as a potential carcinogen by the United States National Institute for Occupational Safety and Health.[1][2]