6) Physical development, where the source of metal ions for precipitation is the developer solution, is distinguished In photographic literature from the more common "chemical or direct development," where the source of the oxidant is the lattice of the exposed grain in the photographic emulsion.7 (7) T. H. James in "The Theory of the Photographic Process," 3rd ed, C. E.

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From data at 25°and ionic strength 1.0 M in various media, assuming negligible temperature dependence over the range 5-20°, as has been found at zero ionic strength.16 (20) F.

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AIC40679U Tetramethylammonium fluoride and hydroxide form stable monohydrates from which water is removed only with difficulty at high temperatures with concurrent decomposition to trimethylamine. The infrared spectra of the monohydrates are completely different from those of the higher clathrate hydrates and show, in addition to cation bands and stretching and bending bands representative of strongly hydrogen-bonded 0-H, two intense bands in the region assigned to rocking or torsional modes of tightly coordinated water (tricoordinated oxygen). Cation C-H to anion hydrogen bonding is present but is not strong enough to account for the third coordinate link to water. This fact, coupled with steric limitations on anion size and the appearance of the cation infrared spectra of the hydrates, suggests that discrete, probably dinegative, water-anion species exist in these salts. This is supported by symmetry coordinate analysis of the proposed molecular ions 2nd by topological equivalent-orbital approach comparisons Contribution from the N-Trimethylborazine undergoes reversible addition reactions with hydrogen halides to form compounds of the empirical formula ( C H~)~N~B~H Y~H X .At elevated temperatures, hydrogen-halogen exchange occurs to yield B-halogenated derivatives of N-trimethylborazine and hydrogen. Bromine reacts under equivalent conditions to yield the previously unreported N-trimethyl-B-dibromoborazine. Hydrogen bromide forms a 3:l adduct with B-trichloroborazine but the analogous reaction between hydrogen chloride and B-tribromoborazine could not be effected. The infrared spectra of the hydrogen halide adducts were recorded in the 4000-650-cm-1 region and partial assignments are proposed.