A Series of the Twelve-Vertex Ferratricarbollides [2-(eta(5)-C(5)H(5))-9-X-closo-2,1,7,9-FeC(3)B(8)H(10)] (Where X = H(2)N, MeHN, Me(2)N, Bu(t)()HN, Bu(t)()(Me)N). A Highly Stable Metallatricarbaborane System with Amine Functions in the Para Position to the Metal Center.

Abstract

Treatment of the zwitterionic amine tricarbollides of general formula 7-XH-nido-7,8,9-C(3)B(8)H(10) (1) [X = H(2)N (1a), Me(2)N (1b), Bu(t)()HN (1c), Bu(t)()(Me)N (1d)] with [(eta(5)-C(5)H(5))Fe(CO)(2)](2) in refluxing xylene for 24 h resulted in the formation of a series of new mixed-sandwich metallatricarbollides [2-(eta(5)-C(5)H(5))-9-X-closo-2,1,7,9-FeC(3)B(8)H(10)] (2) [X = H(2)N (2a), Me(2)N (2b), Bu(t)()HN (2c), Bu(t)()(Me)N (2d)] in yields 16-54%. The reaction of 1d is associated with partial loss of isobutylene and formation of the 9-MeHN-derivative 2e. Derivatives 2a and 2c were also isolated from reactions between the thallium salts Tl(+)[7-X-nido-7,8,9-C(3)B(8)H(10)](-) (Tl(+)1(-)) [X = H(2)N (Tl(+)1a(-)), BuH(t)()N (Tl(+)1c(-))] and [(eta(5)-C(5)H(5))Fe(CO)( 2)I] in refluxing toluene (yields 38 and 55%, respectively). All complexes of type 2 contain amine functionalities in para-positions with respect to the metal center, the complexation being in all cases associated with an extensive rearrangement 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 diffraction study.