A series of the twelve-vertex ferratricarbollides [2-(eta(5)-C5H5)-9-X-closo-2,1,7,9-FeC3B8H10] (Where x = H2N, MeHN, Me2N, (BuHN)-H-t, Bu-t(Me)N). Ahighly stable metallatricarbaborane system with amine functions in the para position to the metal center

Treatment of the zwitterionic amine tricarbollides of general formula 7-XH- nido-7,8,9-C3B8H10 (1) [X = H2N (1a), Me2N (1b), (BuHN)-H-t (1c), Bu-t(Me)N (1d)] with [(eta(5)- C5H5)Fe(CO)(2)](2) in refluxing xylene for 24 h resul ted in the formation of a series of new mixed-sandwich metallaticarbollides [2-(eta(5)-C5H5)-9-X-closo-2,1,7,9-FeC3B8H10 (2) [X = H2N (2a), Me2N (2b), Hu(t)HN (2c), (BuMeHN)-Me-t (2d)] in yields 16-54%. The reaction of Id is associated with partial loss of isobutylene and formation of the 9-MeHN-der ivative 2e. Derivatives 2a and 2c were also isolated from reactions between the thallium salts T1(+)[7-X-nido-7,8,9-C3B8H10] (-) (T1(+)1(-)) [X = H2N (T1(+)1a(-)), (BuHT)-T-t (T1(+)1c(-))] and [(eta(5)-C5H5)Fe(CO) I-2] in ref luxing toluene (yields 38 and 55%, respectively). All complexes of type 2 c ontain amine functionalities in para-positions with respect to the metal ce nter, the complexation being in all cases associated with an extensive rear rangement of the cluster carbons into positions of maximum separation. The structures of all compounds were established by high-field NMR spectroscopy and mass spectrometry, and that of 2c was determined by an X-ray diffracti on study.