A stable fullerene charge-transfer complex in the solid state: HMTTEF–C60

Abstract
The first stable complex of C60 with an organic electron donor has been synthesised; the complex, having C60 and HMTTEF (hexamethylenetetratellurafulvalene) in a 1 : 1 ratio, is black, insulating, weakly magnetic, insoluble in most solvents and stable in air.