Dichlorine monoxide

If chlorine water is boiled the chloricfl) acid decomposes as above, but a little may break down into steam and the acid anhydride, dichlorine monoxide ... 

The smell of chlorine water, somewhat different from that of gaseous chlorine, may be due to minute amounts of evolved dichlorine monoxide ... 

Chlorine forms several very reactive, unstable oxides. Dichlorine monoxide CI2O is a yellowish gas at room temperature, the liquid... 

Cm ORINEOXYGENACIDSAND SALTS -DICm.ORINEMONOXIDE,HYPOCm.OROUSACID,ANDHYPOCm.ORITES] (Vol5) Dichlorine monoxide [7791-21-1]... 

Dichlorine monoxide, hypochlorous acid, and hypochlorites. Chlorous acid, chlorites, and chlorine dioxide. 

Dichlorine monoxide is the anhydride of hypochlorous acid the two nonpolar compounds are readily interconvertible in the gas or aqueous phases via the equilibrium CI2 O + H2 0 2H0Cl. Like other chlorine oxides, CI2O has an endothermic heat of formation and is thus thermodynamically unstable with respect to decomposition into chlorine and oxygen. Dichlorine monoxide typifies the chlorine oxides as a highly reactive and explosive compound with strong oxidhing properties. Nevertheless, it can be handled safely with proper precautions. 

Dichlorine monoxide, which exists in very low equiUbrium concentrations in dilute HOCl solutions, is nevertheless a kineticaHy significant reactant. Eor example, although tetracyanonickelate(II) can be oxidized by chlorine in aqueous solution to /n j -Ni(III) (CN)4(H20)2 , the second-order rate constant at 25°C for oxidation with CI2O is 40 times greater than for CI2 and 2.6 x 10 greater than for HOCl (31). 

Dichlorine monoxide, generated in situ in the presence of CCl by reaction of CO2 and NaOCl, has been used in preparation of substituted hydra2ines (48). Dichlorine monoxide reacts with finely divided cyanuric acid in a fluidized bed forming dichloro- and trichloroisocyanuric acids (49) and with sodium cyanurate monohydrate yielding sodium dichloroisocyanurate monohydrate (50) (see Cyanuric and isocyanuric acids). 

Dichlorine monoxide can also be prepared from concentrated HOCl solutions by vacuum distillation (55), by stripping with air (56,57), and by treatment with anhydrous Ca(N02)2 (58). It can also be prepared by treatment of aqueous HOCl or Ca(OCl)2, mixed with (C4H20)2P04 and CCl, with concentrated sulfuric acid (59,60). 

Dichlorine monoxide can be quantitatively determined alone or in admixture with CI2, by iodometry the acid consumed is a direct measure of CI2O (65). The reactions involved are... 

Dichlorine monoxide is an intermediate in the manufacture of calcium hypochlorite. It has been used in sterilization for space appHcations (70) (see Sterilization techniques). Its use in the preparation of chlorinated solvents (71) and chloroisocyanurates has been described. Chlorine monoxide has been shown to be effective in bleaching of pulp (qv) and textiles (72—74). 

J. A. WojTowicz, Dichlorine monoxide, hypochlorous acid and hypochlorites. Kirk-Othmer Encyclopedia of Chemical Technology, 4th edn., Wiley, New York, 1993, Vol. 5, pp. 932-68. J. J. Kaczur and D. W. Cawlfield, Chlorine dioxide, chlorous acid and chlorites, ibid., pp. 968-91. 

We next consider the synthesis and chemical reactions of the oxides of chlorine. Because the compounds are strongly endothermic and have large positive free energies of formation it is not possible to prepare them by direct reaction of CI2 and O2. Dichlorine monoxide, CI2O, is best obtained by treating freshly prepared yellow HgO and CI2 gas (diluted with dry air or by dissolution in CCI4) ... 

Scheme Some reactions of dichlorine monoxide. [In addition AsCla V02Cl Tia4 TiOCl2-]< >...

Shortly after a mixture of the four ingredients had been compressed into tablets, incandescence and an explosion occurred. This may have been caused by interaction of the oxidant and starch, accelerated by the acid salt, but may also have involved dichlorine monoxide liberated by the same salt. 

A mixture of the anhydride and hypochlorous acid exploded violently while being poured. Some acetyl hypochlorite and/or dichlorine monoxide may have been formed. 

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