Synthesis and reactivity of propionitrilium derivatives of cobalt and iron bis(dicarbollides)

The synthesis of propionitrilium derivatives of cobalt and iron bis(dicarbollides) [8-EtC N-3,3 '-M(1,2-C2B9H10)(1',2'-C2B9H11)] (M = Co, Fe) by the reaction of the cesium salts of the parent bis(dicarbollide) anions [3,3'-M(1,2-C2B9H11)(2)](-) with propionitrile in the presence oftert-butyl bromide is described. The nucleophilic addition reactions of water, alcohols, and thiols with the -N+=C triple bond of the prepared nitrilium derivatives were studied and the corresponding iminols [8-EtC(OH) HN-3,3'-M(1,2-C2B9H10)(1',2'-C2B9H11)] (M = Co, Fe), imidates [8-EtC(OR) HN-3,3 '-M(1,2-C2B9H10)(1',2'-C2B9H11)] (M = Co, R = Me, Et, i-Pr, Bu; M = Fe, R = Et), and thioimidates [8-EtC(SR) HN-3,3'-Co(1,2-C2B9H10)(1',2'-C2B9H11)] (R = Et, Bu, Hx) were synthesized as mixtures ofEandZ-isomers, some of which could be separated by the column chromatography on silica. The molecular structure of [(Z)-8-EtC(OiPr) HN-3,3'-Co(1,2-C2B9H10)(1',2'-C2B9H11)] was determined by single-crystal X-ray diffraction study.