The Chemical Properties of Dioxygen Difluoride' by A
Total Page：16
File Type：pdf, Size：1020Kb
1380 A. G. STRENG Vol. 85 (CH3)3Sn:-ion, and, by the trends in coupling constants tion of H for CH3in the coupling Sn-CH3 (starting with observed in the neutral stannanes, substitution of a (CH3)4Snand extrapolating to the methylstannanes) . hydrogen for a methyl group in the trimethyltin anion There have been other observations of non-additivity would be expected to increase the SnCH3 coupling, as of substituent effects, such as the increasing positive observed. Due to rapid solvolytic proton exchange, deviations obtained for C-I€ or Si-H coupling, by the tin-bonded hydrogen atom would not be expected substitution of halogens (particularly F) in CH4 or to split the tin-methyl resonance into a doublet, nor SiH4,20or for the coupling Sn-CH3 upon substitution of would it be possible to observe a resonance for this C1 for CH3 in (CH,)&I.~ A discussion of possible proton as distinct from the solvent protons in such explanations for these deviations is given by Juan and dilute solutions. Gutowsky.*Oh Substituent Effects on Sn-H and Sn-CH3 Coupling.- The effect of substituting CH3 for H on the coupling Acknowledgment.-The authors wish to thank Sn-H in SnH4 and the methylstannanes is not strictly Professor Daniel E. Kivelson of this Department and additive, as illustrated in Fig. 1. The coupling for Dr. J. R. Holmes of the Allied Chem. Corp., hforris- (CHd3SnH strongly deviates from the extrapolated town, pi. J., for valuable discussions; Rlr. Richard straight line, and is larger than might have been ex- Gillespie for assistance in obtaining magnetic resonance pected if the effects were additive. The first three spectra on the 40 Mc. instrument; and the Ethyl points are nearly linear, except for a slight alternation Corporation for a sample of (CH3)4Pb. in positions which, though small, we nevertheless feel (20) (a) K Muller and P I Rose, J Aril Chcm Soc , 84, 3973 (1962), is real. B similar pattern of behavior, including a (h) (J' discussion and references in C Juan and H S Gutowsky, J Chem slight alternation, is observed for the effects of substitu- Phys , 37, 2198 (1962) [CONTRIBUTED BY THE RESEARCH INSTITUTE OF TEMPLEUNIVERSITY, PHILADELPHIA 44, PENNA.] The Chemical Properties of Dioxygen Difluoride' BY A. G. STKENG RECEIVEDDECEMBER 5, 1962 Dioxygen difluoride has a remarkably high oxidizing power, even at very low temperatures. The reactivity of OzFt with Clz, Br2, I*, P, S, and their lower fluorides, as well as with the fluorides of nitrogen, with HCl, HBr, H?S and with some other compounds was studied. Formation of intermediate addition products was observed in the reactions with ClF, BrF3, SF4, HCl and HBr. Most intermediates have only a transitory existence. Introduction Reagents Used Dioxygen difluoride, 02Fz,is the second member of Dioxygen difluoride was prepared directly from the the oxygen-fluoride family, consisting of OFs,2a OZF,,2h elements by the method described el~ewhere.~It was 03Fs3and O~FZ.~It is an orange-yellow solid which stored in a Pyrex glass cylinder, frozen at 90°K. melts at 109.7'K. to an orange-red liquid. Dioxygen Chlorine monofluoride, ClF, nitryl fluoride, N02F, difluoride is sufficiently stable at temperatures below its phosphorus trifluoride, PF3, and silicon tetrafluoride, melting point but decomposes rapidly into O2 and F2 SiF4,were also prepared by the well known methods.'O-13 at temperatures close to its normal boiling point, 216'K. All other reagents were the commercial products of Dioxygen difluoride has been known since 1933, when the highest available purity, supplied by Stauffer Ruff and Menzel achieved its preparation.2h Since Chemical Co. General Chemical Division of Allied then a number of investigations have been devoted to Chemical Co., Pennsalt Chemicals Corp., E. I. du the methods of preparation of 02F2and to its thermo- Pont de Nemours and Co., Matheson Co., Air Reduc- dynamic and physical properties6-8; but very little tion Co. and others. Most of these reagents were fur- has been published about its chemical properties. Only ther purified by fractional distillation. recently, when this paper was ready for typing, there appeared a very interesting article, by R. T. Holzmann Experimental Technique and M. S. Cohen Ilnorg. Chem., 1, 972 (1962)], The experiments were carried out either in a closed vacuum describing the reaction of 02F2with tetrafluoroethylene. system made of Pyrex glass or in one made of Kel-F, fitted with Since dioxygen difluoride is stable only at low tem- stainless-steel valves and T-pieces. Mercury manometers with a protective layer of Kel-F oil were used for measuring the gas peratures, its chemistry was studied in a temperature pressure. region which is substantially below the usual range of The experimental conditions were varied according to the chemical studies. requirements of each combination of reagents. In most cases, 02F~was first frozen on the walls or on the Raschig-ring packing An exploratory study of the behavior and reactivity of the reaction vessel. The second reagent was then added in of dioxygen difluoride with various substances was small portions by vacuum distillation and condensed above the made in order to obtain information on the basic chem- 02F2. The vessel was then slowly warmed to the temperature of istry of 02F2 and its ability to form addition products. reaction. The solid and liquid products remained in the re- action vessel, and the gaseous products were removed for analy- (1) This paper describes a part of the wurk sponsored by the Office [IC sis. The reaction vessel was then cooled again to the original Naval Research, under Contract Sonr-3085(01). ____ ~ (2) (a) P. Lebeau and A. Ilamiens, Compl. rend., 185, 652 (1927); (h) (9) A. G Streng and A. V. Grosse, "Addition and Substitution Com- 0. Ruff and W Menzel, Z,anoyg. zi. allgem. Chem.. 211, 204 (1933). pounds of Oxygen Fluorides," Second Annual Progress Report for the Office (3) S. Aoyama and S. Sakuraha, J. Chem. Soc. Japan, 69, 1321 (1938). of Naval Research, Contract Nonr-3085(01), Research Institute of Temple (4) A. V. Grosse, A. G. Streng and A. 11. Kirshenhaum, J. Am. Chem. University, Philadelphia 43, Pa., January 19, 1962. Soc., 83, 1004 (1961). (10) 0. Ruff, E. Ascher and F. Lads, Z. anorg. alleem. Chem., 176, 256 (.5) 0. Ruffand W. Menzel, 2. anorg. 11. allgem. Chem., 217, 85 (1931). (1928) (0) H. J. Schumacher and P. Frisch, %. physik. Chem., B37, 1 (1937). (11) Georg Brauer, "Handbuch der Praparativen Anorganischen Chemie ," (7) A. 1). Kirshenhaum and A. V. Grosse, J. Am. Chem. Soc., 81, 1277 Ferdinand Enke Verlag, Stuttgart, 1954. (19.59). (12) L. I.ehouche, W. Fischer and W. Biltz, Z. am%'e. allgem. Chrm., 207, (8) A. I). Kirshenbaum and A. G. Streng, J. Cheiii. Phys., 35, 1410 64 (1932). (1961) (13) 8. Ruff and E. Ascher, ibid., 196, 413 (1931). May 20, 1963 CHEMICALPROPERTIES OF DIOXYGENDIFLUORIDE 1381 temperature and a new portion of reagent was added. The melting point of 02F2 and the excess of OzFZ pumped procedure was repeated until all the OZFZwas consumed. The reaction products (gaseous, liquid and solid) were measured and off. Hydrogen fluoride, hydrogen peroxide and water analyzed. were the reaction products. The amounts of the prod- If O~FZwas used as liquid, it was condensed in the bottom of the ucts indicate that the reaction proceeded in accordance reaction vessel. In some cases reactions were performed with with the summary equation 0sFz dissolved in a suitable solvent. Two-limb apparatus was used for some of the reactions between two liquid reagents or 0zFz + 5H. +2HF 4- 0.5HzOz + H20 (1) their solutions. The reagents were condensed separately in the Traces of Hi04 were also formed. No radical or other two limbs and one liquid was added to the other by tilting the apparatus. intermediate products have been found. If a reaction between liquid OZFZ(or its solution) and a gas was studied, the gas, usually diluted with an inert gas, was Reaction with Cl,, C1F and HC1 bubbled through the liquid. The reagents and the reaction products were measured care- A rapid addition of chlorine to dioxygen difluoride fully. In the gaseous and in the liquid phase, they were meas- cooled to about 140'K. caused a violent explosion. ured volumetrically; in the solid phase, by weight. The However, when small portions of CIz were added slowly reaction products were identified by chemical methods, by de- to OzF2cooled to 130'K., a violet intermediate product termination of their physical constants and by infrared spectrog- raphy. did form, together with ClF3.16 Here, the first step Liquid nitrogen, liquid oxygen, various Freons and Dry Ice was most probably the fluorination of C12 to CIF were used as refrigerants. OzFz Cls ----f 02 2C1F It must be emphasized that inadequate cooling or a fast addi- + + (2) tion of reagents to O~FZand oice vena caused explosions. After ClF was formed, it reacted further with 02F2, as The Reactivity of with Organic Compounds described below. 02F2 The study of the reaction of OsF2 with C1F showed Being a high energy oxidizer, dioxygen difluoride that if the reaction is carried out without special pre- reacted vigorously with organic compounds, even at cautions at temperatures above 140'K., the two sub- temperatures close to its melting point. It reacted in- stances react violently with heat evolutions following stantaneously with solid ethyl alcohol, producing a blue the equation flame and an explosion. When a drop of liquid 02F2 OzF2 CIF +02 ClFa 30.1 kcal. was added to liquid methane, cooled at 90°K., a white + + + (3) flame was produced instantaneously, which turned The ClF abstracts the fluorine from 02F2, forming ClF3 green upon further burning.