Carbonyl chloride fluoride

Under normal conditions of temperature and pressure, COCIF is a gas. It is colourless in both the gaseous and condensed states, and has an odour similar to, but distinguishable from, phosgene. It is non-flammable. 

The synonyms of carbonyl chloride fluoride are carbonic chloride fluoride (currently used in Chemical Abstracts), carbonyl chlorofluoride, and monofluorophosgene. The Chemical Abstracts Registry No. is [353-49-1]. COCIF is included in the European inventory of existing chemical substances (EINECS) [602a], since it was included in the core inventory [602] its EINECS number is 206-533-7. No fuli-scale commercial synthesis of COCIF has ever been operated. 

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Preparation of Arylcarboxylic Acids and Derivatives. The general Friedel-Crafts acylation principle can be successfully appHed to the preparation of aromatic carboxyUc acids. Carbonyl haUdes (phosgene, carbonyl chloride fluoride, or carbonyl fluoride) [353-50-4] are diacyl haUdes of carbonic acid. Phosgene [75-44-5] or oxalyl chloride [79-37-8] react with aromatic hydrocarbons to give aroyl chlorides that yield acids on hydrolysis (133) ... 

The conversion of alcohols to the corresponding alkyl fluorides by the pyridine or boron trifluoride catalyzed decomposition of alkyl fluoroformates formed by the addition of 2, or of carbonyl chloride fluoride, to alcohols has been reported.47,48... 

Similar reactions follow on after the disproportionation of carbonyl chloride fluoride into dichlorodifluoromethane and carbon dioxide, following the primary reaction. 

If carbonyl chloride fluoride ts heated to 425 C in an autoclave in the presence of activated carbon impregnated with iron(III) chloride, dichlorofluoromethane, chlorotrifluoromethane and carbon tetrafluoride are obtained in addition to carbon dioxide.21-22... 

In the carbonyl compounds FC(0)Y the C—F bond distances show a strong dependence on the substituent X and shorten from 136.2(2) pm in acetyl fluoride (Y = Me) to 131.6(1) pm carbonyl fluoride (Y = F). In formyl fluoride (Y = H) and carbonyl chloride fluoride (Y = Cl) the C—F bond lengths are intermediate. When CF2 groups are double-bonded to C, O, S or Se, the C—F bond distances are remarkably constant and range only from 131.5 to 131.9 pm. Such bond lengths, however, are shorter by ca 1.5 pm in compounds with C=N double bonds, such as methanimine or 2,3-diaza-l, 3-butadiene. In both compounds only mean values for the C—F bond distances can be derived from the ED experiments. Ab initio calculations for perfluoromethanimine predict that the C—F bond trans to N—F is longer by 0.4 pm than the cis bond. 

Silicon(IV) fluoride reacts in a quartz tube with phosgene to give carbonyl chloride fluoride with 100% selectivity and 42% conversion, at 420 C no COFj is formed [377]. 

There was no reaction when difluorine was bubbled through liquid phosgene at 6 C, but the vapour over the reaction mixture was explosive [992]. However, when a mixture of difluorine and phosgene were passed over calcium fluoride, a reaction (frequently explosive) occurred to yield a liquid which boiled at -42 C [992]. Although then thought to be a mixture of COFj and dichlorine, it is likely that this reaction produced the first samples of carbonyl chloride fluoride (cf. Section 9.1.1), thirty-seven years before this material was first identified. 

Suitable gas chromatographic conditions for the analysis of carbonyl difluotide in mixtures with phosgene, carbonyl chloride fluoride, COj and air are as follows [84a] ... 

Synthesis of carbonyl difluoride from carbonyl chloride fluoride... 

A new and potentially economic route for the preparation of carbonyl difluoride has been found recently. This involves the catalytic disproportionation of carbonyl chloride fluoride over activated charcoal in a flow system at low temperatures (20-177 C) [8Sa,ICI110]. The high yields obtained in the process correspond closely to those calculated for the equilibrium reaction ... 

Section 3.2.3.1.2) can be employed for the detection of carbonyl chloride fluoride. 

In 1946, carbonyl chloride fluoride, COCIF, was reported in the open literature for the first time [1885] (although a US Defense report appeared in 1942 [1883a]) it was prepared (ca. 25% yield) by the reaction between phosgene and anhydrous hydrogen fluoride in a copper bomb at 80 C and 1.93 MPa, in the presence of a trace of antimony(V) chloride as well as hydrogen chloride, some by-product COFj was also formed [1885] ... 

Although it was not identified as such at the time, the first report of a material which could have been carbonyl chloride fluoride appeared in 1919 [992]. The reaction (oft explosive) between phosgene and difluorine at 200 C, in the presence of calcium fluoride, produced a liquid which boiled at ca. -42 "C [992]. The product was thought, at the time [992], to be a mixture of COF and dichlorine, but the proximity if its boiling point to that of COCIF is too close for coincidence. 

H - Hjgg, -AHf, and -dGj on facing page) of carbonyl chloride fluoride (ideai gas) in the temperature range of 0-1000 K [3S9aa]. 

Carbonyl chloride fluoride does not associate in the gas phase [1885], and possesses the expected planar Cj structure. The results of the published structural studies are summarized in Table 16.8 the most reliable determination is the result of the combined electron diffraction and microwave spectroscopic study [1531]. Remarkably, prior to these data being published, the fully optimized geometry calculated by ab initio molecular orbital methods [1532] was demonstrated (correctly) to be far superior to the best experimental results available (see Table 16.8). Rather unfortunately, a more recent ab initio study [2176a] performed rather... 

Although the most extensively recorded aspect of phosgene chemistry is its interaction with compounds at a nitrogen centre, only three reactions of carbonyl chloride fluoride with amines have been reported. No reports have appeared concerning the reactions of COCIF with tertiary amines, amino acids, hydrazine derivatives, imino compounds or nitrogen-containing heterocycles, to name but a few unstudied reagents. 

Treatment of a thiol or thiophenol with carbonyl chloride fluoride in the presence of a tertiary amine (in an inert solvent such as heptane) results in the formation of the corresponding thiol fluoroformate in 75-85% yield [1555a] ... 

The following is a selective list of some typical suppliers (USA and Western Europe) who are currently, or who have recently, produced research quantities of phosgene, isotopically-labelled phosgene, carbonyl difluoride or carbonyl chloride fluoride, for laboratory research or small-scale development studies. This list is always in a state of flux, but it is hoped that it will at least provide some useful starting points in the search for a supplier. Convenient laboratory syntheses of these materials are give in Appendix A5. 

The commercial availability of carbonyl chloride fluoride is, to say the least, variable appearing on suppliers lists e.g. Fluorochem and Ozark-Mahoning) in some years, and not in others. When available, this material has a price that is disproportionately high relative to phosgene and carbonyl difluoride, reflecting the speciality nature of the compound and the absence of any bulk production. 

Carbonyl chloride fluoride is conveniently prepared from the reaction of the trichlorofluoromethane, CCI3F, with sulfur(IV) oxide ... 

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