The fullerenes—precursors for 21st century materials

Abstract

The fullerenes represent a new molecular form of carbon. Their remarkable physico-chemical properties make them desirable as components in new materials, and in order to exploit these properties it is necessary to understand the principles for the preparation of both pure buckminsterfullerene (C 60) derivatives of known addition number and pattern, and C 60 containing materials of known composition and structure. C 60 is brominated by Br 2 in a variety of solvents to give either C 60 Br 6 or C 60 Br8, depending upon the particular solvent used. Crystals of C 60 Br 6.Br 2.CCl 4, C 60 Br 6.xBr 2 (x ≈ 2), and C 60 Br 8.Br 2 (x ≈ 2) are obtained from CCl 4, C 6 H 6, and CS 2 respectively. Reaction of C 60 with ICl yields C 60 Cl 6, which has the same addition pattern as C 60 Br 6. Cocrystallisation of C 60 and I 2 from C 6 H 5 CH 3 solution yields the intercalate C 60.I 2.C 6 H 5 CH 3 which contains discrete C 60 and I 2 molecules. Slow evaporation of C 6 H 6 solutions of C 60 gives crystals of the solvate C 60.4C 6 H 6. Mixing of saturated C 6 H 6 solutions of C 60 and (η 5 -C 5 H 5) 2 Fe gives a dark red solution from which black crystals of C 60.2[(η 5 -C 5 H 5) 2 Fe] are deposited. In a similar manner cocrystallisation of C 60 and (η 5 -C 5 H 5) 4 Fe 4 (CO) 4 from C 6 H 6, solution yields black crystals of the intercalate C 60.(η 5 -C 5 H 5) 4 Fe 4 (CO) 4.3C 6 H 6. © 1994, Walter de Gruyter. All rights reserved.