Übergangsmetall—carbin-komplexe : LIX. Keteniminyl-komplexe des mangans und rheniums durch addition von isocyaniden an kationische carbin-komplexe

Dicarbonylcyclopentadienylphenylcarbynemanganese tetrachloroborate, C₅H₅(CO)₂MnCC₆H₅] BCl₄], reacts with the isocyanides CH₃NC, cyclo-C₆H₁₁NC and t-C₄H₉NC, affording the thermolabile, dark green keteniminyl-complexes C₅H₅(CO)₂MnC(C₆H₅)CNR] BCl₄] (R′  CH₃, cyclo-C₆H₁₁, t-C₄H₉). A clear stabilisation results when SbCl₆^- replaces BCl₄^- as counterion, for example in the salt C₅H₅(CO)₂MnC(C₆H₅)CNC₄H₉] SbCl₆]. The product obtained by the reaction of C₅H₅(CO)₂ReCCH₃] BCl₄] with t-C₄H₉NC is extremely labile and could up to now only be examined using infrared technique.Under carefully controlled conditions, the t-C₄H₉ group splits off the manganese product C₅H₅(CO)₂MnC(C₆H₅)CNC₄H₉] BCl₄], yielding the carbene complex C₅H₅(CO)₂MnC(C₆H₅)CN. Decomposition can be reversed by N-alkylation of the carbene complex with t-C₄H₉Cl/SbCl₅, establishing an alternative synthetic route towards C₅H₅(CO)₂MnC(C₆H₅)CNC₄H₉]SbCl₆].