SANDWICHED METALLACARBORANES OF F-BLOCK ELEMENTS

The dilithium complexed ''carbons adjacent'' nido-carborane anions of the type [2-(SiMe(3))-3-(R)-2,3-C2B4H4](2-) [R = SiMe(3), Me, H], as w ell as the disodium and dilithium complexed ''carbons apart'' nido-car borane anions [2-(SiMe(3))-4-(R)-2,4-C2B4H4](2-) [R = SiMe(3), Me] hav e exhibited different reactivity patterns toward various lanthanide ha lides, depending upon the solvents used in the reactions and the natur e of the group 1 metal. Both the tetrahydofuran (THF) and N, N, N, N-t etramethylethylenediamine (TMEDA)-solvated closo-dilithiacarboranes ha ve been found to be important synthons in the production of novel meta llacarboranes of f-block elements. Several unprecedented examples of l anthanide-carborane complexes have been synthesized, their structures determined and reactivity studied.