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A series of monoiodoborane adducts LBH 2 I (L = N(CH 3 ) 3 pyridine, 3-methylpyridine, 4-methylpyridine or (C 6 H 5 ) 3 P) has been prepared. Ideally, the addition of suitable amines, phosphines or trimethylarsine to a benzene solution of these adducts would be expected to yield boronium salts containing two different donors coordinated to a central boron atom. These salts, of the general formula LL′BH 2 I, were formed in several instances (L′ = (CH 3 ) 3 P, (C 6 H 5 ) 3 P, (CH 3 ) 3 N). Six previously unreported boronium cations have been characterized. The iodide salts of these boronium cations may be easily converted to their hexafluorophosphate analogs except for the large ligands such as (C 6 H 5 ) 3 P or 3-methylpyridine. In contrast, trimethylarsine reacted with 4-MepyBH 2 I in benzene to give 4-MepyH + I − and [(CH 3 ) 3 AsI] + I − . The proton and boron NMR spectra of all species were investigated when experimentally feasible.

The addition of an equivalent of Cl 2 , Br 2 or I 2 to a solution of Na[H 3 BCN] in glyme (1,2-dimethoxyethane) yields the cyanoborane cyclic oiligomers previously reported. The addition of an excess of a Lewis base (e.g. a pyridine, a tertiary amine or a tertiary phosphine) to the cyanoborane yields a cyanoborane adduct, LBH 2 CN. The addition of an excess of chlorine yields a solution believed to contain [glyme]-BH 2 CN. This solution reacts slowly with Lewis bases (L) to yield LBH 2 CN, and small amounts of chlorinated cyanoborane adducts. The proportion of chlorinated products relative to LBH 2 CN increases as the amount of moisture in the reaction mixture increases and as the base strength of L is reduced. The chlorination of LBH 2 CN in moist benzene yields LBCl 2 CN as the principal product when L is pyridine, while a complex misture is obtained when L = (C 2 H 5 ) 3 N.

The reaction of trimethylgallium or trimethylindium with 2,3-dicarba-nido-hexaborane(8) yields the closed polyhedral species 1-CH3GaC2B4H6 and 1-CH3InC2B4H6, respectively, in which the metal atom in each case forms one apex of a pentagonal bipyramidal cage. These carboranes have been structurally characterized by boron-11 and proton NMR, mass spectra, and infrared spectra, and by a single crystal X-ray diffraction study of the gallium compound. The X-ray results have disclosed two distinctive features: The gallium atom is closer to the boron atoms than to the carbon atoms in the five-membered equatorial ring; The Ga-CH3 axis is tilted by 23 deg with respect to the perpendicular to the equatorial plane. These findings are interpreted in terms of a qualitative molecular orbital model. The gallium and indium compounds are thermally stable to at least 100C but pyrolysis at high temperatures generates 2,3-C2B4H8. Bromine attacks both metallocarboranes at room temperature, destroying the cage structure and forming the dimer of (CH3)2GaBr and, presumably, the indium analog respectively. (Author)

The new compound tris(trifluoromethylthio)borane, (CF3S)3B, has been prepared by interaction of BBr3 and Hg(SCF3)2 in hydrocarbon solvent. The thioborane is a fairly volatile liquid which decomposes slowly at room temperature yielding BF3 and SCF2. Due to the enhanced Lewis acidity of B(SCF3)3 relative to its proton analog, reaction of the compound with excess trimethylamine gives a white 1:1 adduct whereas B(SCH3)3 does not. The new adduct decomposes in the solid state or in solution to yield (CH3)3NBF3 and a brown-yellow solid material.

The following new compounds containing perfluoroalkyl-tellurium linkages have been synthesized: CH3TeCF3, (CF3)2Te, CH3TeC2F5, (C2F5)2Te. These preparations were brought about by the photochemical interaction of (CH3)2Te and an appropriate perfluoroalkyl iodide in a vycor tube at 310 nm wavelength. The resulting mixture of tellurides, RfTeCH3 and (Rf)2Te in which Rf = CF3 or C2F5, cannot be separated by trap-to-trap distillation, but the relative amounts of each product were determined by 19F NMR spectroscopy. The clear yellow tellurides are air stable, but yield either CF3H or C2F5H on basic hydrolysis. No reaction was noted with CH3Cl up to 80°, but at 215° a mixture of CH3TeCF3 and (CF3)2Te interacted with benzyl chloride to give C6H5CH2CF3 in a 3·4 cent yield.

New 1 : 1 adducts of BBr3 and BI3 with (CH3)3As and (CH3)3Sb are reported. The (CH3)3As adducts are stable indefinitely at room temperature under an inert atmosphere while the (CH3)3Sb compounds slowly decompose at that temperature to form (CH3)3SbX2 (X = Br, I). Boron-11 and proton NMR data suggest that these species may exist as ions in chloroform solution.