Isolation and Characterization of a Carbene Derivative of La@C<sub>82</sub>

The photochemical reaction of La@C<sub>82</sub> with 2-adamantane-2,3-[3H]-diazirine affords adduct <b>2</b>, La@C<sub>82</sub>(Ad), in a quantitative and highly selective manner. The structure of compound <b>2</b> is confirmed by ESR, MS, and UV−vis−NIR spectroscopies, and the first X-ray crystallographic characterization of an endohedral monometallofullerene derivative is reported.