wlth Metals Inside

Fullerenes with a single lanthanum atom trapped on the inside of the carbon cage were produced by laser vaporization of a lanthanum oxide/graphite composite rod in a flow of argon gas at 1200 OC. When sublimed with Ca and C70, they formed an air-stable film containing principally Lacm, Lac,,,, Lac7,, and Lacs2. When dissolved in toluene and exposed to air, Lacs2 was found to be uniquely stable. Evidence was also obtained for coalescence reactions between these fullerenes at high temperatures to form larger cages with as many as three lanthanum atoms inside. Indications have also been obtained for the successful production of KCm, CS9B, and KCS9B where the boron has substituted for a carbon in the soccerball cage. The use of the @I symbol is advocated for specifying such complex fullerenes as (K@CS9B).