secondary cells with lithium anodes and immobilized fused_salt

I. Introduction
108.
RE7IIEw OF ADVANCED INORGANIC OXIDIZFRS
Edward W. Lawless and Robert J. Rowatt
Midwest Research Institute, Kansas City, Missouri
In this Faper the Froperties and chemistry of advanced inorganic oxidizers
will be reviewed with emphasis on recent developments. The classes of compounds
w i l l be limited to the cxyzen fluorides, the nitrogen fluorides, the nitrogen fluo-
ride oxides, the halogen fluorides and the halogen fluoride oxides. In general, all
%f the zompoucds described here are highly reactive, toxic materials, and very vola-
tile exceat for ionic derivatives. The growth of chemistry involving 0-F, N-F and
Cl-F comFounds has been remarkable: from about nil in 1946 to over 1030 today.
11. O.y:gen Fluorides and Derivatives
The reported oxygen fluorides, their derivatives and some of their prop-
erties are summarized in Table I. Oxygen difluoride is the only binary compound of
t?is tpe which 1s stable at room temperature, but 02F2 is stable below about -80%
3rd is -,e11 cheracteri-ed. A reasonably good understanding has been gained recently
of the a?parent equilibrium system O4F2 e 202F.
The existeice of O3F2 as a separate entity is in doubt, and the natures of
the reported "O5F2" and "OgFg" are quite uncertain. Oxygen difluoride is comercially
available, while the others are prepared by electrical discharge at low temceratures
fron aporopriate O2-F2 mixtures.
The ;tructures of OF2 and 02F2 have been determined and are compared in
Figure 1 with those of related comnounds. The abnormally long 0-F distance and the
greatly shortened 0-0 bond in 02F2 have led Linett to formulate its structure as
zavirg an essentially four-electron 0-0 bond (as in 02 itself, 1.21 1 bond length)
szd a one-electron 0-F bond (resonating between the two positions). Dioxygen di-
fluoride can, therefore, readily dissociate at the 0-F bond t3 give F atoms and the
stable 09 radical:
az3 is an extremely energetic fluorinating agent. At low temperatures it is more
reactive than fluorine itself and far more reactive than OF2. The latter compound
begins to decompose near 23O0C and many of its reactions require activation by heat
or light. The 02F- radical can be generated by ultraviolet radiation of liquid OF2,
of 0F2-02, F2-02 or F2-N20 mixtures in a matrix, at 4'K, by the decomposition of
04F2 07 FSOpOOF, and in the reaction of CF4 with 02. The OF radical has never been
detected in the gas or liquid phase despite an intensive search.
The reactions o'f the oxygen fluorides are usually simple fluorinations,
but oxygen addition by OF2 can occur especially in aqueous solution or i n reactions