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Vapor-phase rearrangement of (7r-C5H5)Co|>-(3)-l,2-B9C2Hii] (la), (T-C5H5) Co[7r-(3)-l,2-(CH:i)2-1,2-B9C2H9] (2a), and ( -5 5) [ -(3)-µ-1,2-( 2)3-1,2-9 2 9] (3a) at 400-700°y ielded isomeric complexes lb-g, 2b-g, 3d, 3h, and 3i. These compounds incorporate all nine isomeric dicarbollyl ligands and are formed by the migration of the cage carbon atoms over the polyhedral surface. All isomers were separated by thick-layer chromatography and their structures determined on the basis of their chromatographic, electrochemical, and spectral (uv-visible, , and 1LB nmr) properties.Polyhedral rearrangement of boranes, carboranes, and halocarboranes has been known for some time.1 Interest in the rearrangement of metal complexes of the dicarbollyl ligand is of more recent origin. The first thermal rearrangement of dicarbollyl derivatives, viz. those ofNiIV, were reported in 1970 by Warren and Hawthorne. 2 More recently, rearrangement of 3-MCH2-CH3-l,2-B9C2Hn (M = Al, Ga)3 and 3-Ge-l,2-B9-C2Hh4 5has been studied. In the rearrangement of these metallocarboranes, the 1,2-dicarbollyl moiety rearranges to the isomeric 1,7-and 1,6-dicarbollyl structures. Complexes with other isomeric dicarbollyl ligands were not observed. Since, at the present, only three (1,2, 1,7, and 1,12) of the possible nine dicarbollide ions can be obtained by the basic degradation of the parent Bi0C2Hi2 carboranes6 and there are no known synthetic pathways leading to the remaining dicarbollides, it was of interest to study the rearrangement of metallocarboranes to isomeric complexes incorporating the novel dicarbollyl ions. We now wish to report the detailed results of the thermal rearrangement of three monodicarbollyl complexes of cobalt: (tt-C5H5)Co(7r-(3)-l,2-R2-l,2-B9C2H9), R = H (la), R = CHa (2a), and R2 = (CH2)3 (3a)6•7 (Figure 1). ResultsThe starting materials la, 2a, and 3a were synthesized from the corresponding trimethylammonium 1,2dicarbaundecaborate( -1) ions6a•8 according to a modi-(1) For recent reviews see (a) E.

The method reported here utilizes the reaction between sulfur dichloride and N-(trimethylsilyl) sulfinylamine and gives a 68% yield of bis (sulfinylamino) sulfide conveniently. The other product, trimethylchloro-2MesSiNSO + SC12->-S(NSO)2 + 2Me3SiCl silane, was found to be an excellent recrystallization solvent for the amino sulfide. Benzene had been used previously.5The large, yellow rhombic crystals of the product were sensitive to traces of moisture. They could be conveniently handled in an atmosphere of dry nitrogen. The sample went red on heating and appeared to boil after melting, as previously reported.2 The infrared spectrum in carbon disulfide contained two major peaks at 1184 and 988 cm-1, attributable to the asymmetric and symmetric stretching vibrations of the sulfinylamino group.7Experimental Section Sulfur dichloride was purified by distillation in the presence of 10% of phosphorus trichloride,8 which inhibits disproportionation into sulfur monochloride and chlorine; the distillate was promptly used.N-(Trimethylsilyl )sulfinylamine was prepared in 88% yield according to the method of Scherer and Horning9 from tris-(trimethylsilyl)amine10 and thionyl chloride. The fraction boiling at 108°, n2°D 1.4254, was used.Bis (sulfinylamino) Sulfide.-In one experiment, 41.4 g (0.307 mol) of the silylsulfinylamine was placed in a 100-ml two-necked flask, fitted with a reflux condenser, and a 50-ml dropping funnel fitted with a by-pass. The whole apparatus was flushed with and maintained under an atmosphere of dry nitrogen, and 14.5 g (0.145 mol) of sulfur dichloride was slowly added to the sulfinylamine, with stirring. The reaction was exothermic, and fine, yellow' crystals w'ere deposited. The mixture was heated under reflux for 48 hr to ensure complete reaction. Long, yellow' needles formed on cooling and the liquid was then pumped off, trapped (30.2 g), and redistilled to yield trimethylcholorosilane (26.5 g, 87%), bp 57°, «25d 1.3864.The yellow crystals were dissolved in 50 ml of hot trimethylchlorosilane, recrystallized, and filtered under a dry nitrogen atmosphere. They were w'ashed with a little cold trimethylchlorosilane and all traces of solvent were pumped off over a period of 3 hr. The crystals melted in sealed tube at 100-101°( lit.4 mp 100.7°) (14.9 g, 68%).

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