HETEROATOM INCORPORATED CAGES AND CLUSTERS

The significant recent findings in our laboratory are as following: (1 ) The synthesis and crystal structure of the first ''carbons apart'' C 4B8-carborane provided an indirect evidence for the existence of a car borane cuboctahedron, a geometry that was proposed by Lipscomb in 1960 as an intermediate in his classic DSD mechanism for the thermal rearr angement of ortho-carborane to meta-carborane. (2) The first examples of fully sandwiched anionic lithia- and magnesacarboranes and half-san dwich cesia- and magnesacarboranes have been synthesized and structura lly characterized. (3) A number of half- and full-sandwich galla- and indacarboranes were synthesized and their reactivities at the metal ce nter for further complexation were explored. (4) The lanthanide metal reagents exhibited a different reactivity pattern with the ''carbons a part'' carborane ligands than with the corresponding ''carbons adjacen t'' counterparts and further exemplify the role of solvents in determi ning the course of reactions in these systems.