Synthesis and structure of LaSc2N@C(s)(hept)-C80 with one heptagon and thirteen pentagons

Angew Chem Int Ed Engl. 2015 Jan 7;54(2):495-9. doi: 10.1002/anie.201409094. Epub 2014 Nov 20.

Abstract

The synthesis and single-crystal X-ray structural characterization of the first endohedral metallofullerene to contain a heptagon in the carbon cage are reported. The carbon framework surrounding the planar LaSc2N unit in LaSc2N@C(s)(hept)-C80 consists of one heptagon, 13 pentagons, and 28 hexagons. This cage is related to the most abundant Ih-C80 isomer by one Stone-Wales-like, heptagon/pentagon to hexagon/hexagon realignment. DFT computations predict that LaSc2N@C(s)(hept)-C80 is more stable than LaSc2N@D5h-C80, and suggests that the low yield of the heptagon-containing endohedral fullerene may be caused by kinetic factors.

Keywords: X-ray diffraction; cage compounds; density functional calculations; fullerenes; scandium.