Synthesis and Structure of Silicon-doped Heterofullerenes

We report on the synthesis of C_2n-qSiq clusters with 2n0ex0ex=0ex0ex32-100 and $q<4$. The analysis of the abundance distribution and photofragmentation spectra provides clear evidences that such clusters remain in the fullerene geometry and that the Si atoms are located close to each other in the fullerene network. These results are corroborated by ab initio calculations within the density functional theory. The stability and electronic properties of these heterofullerenes are discussed.