Novel fullerene-based ferrocene dyad and diferrocene triad: Synthesis and effects of introduction of fullerene[60] and phenyl linker on the thermodynamic stability, the magnetic properties and the band structure

In this paper, two nanoscale fullerene[60]-based compounds, N-methyl-2-(ferrocenyl) (phenyl) fulleropyrrolidine (C-60-ph-Fc) and N-methyl-2-(diferrocenyl propane) fulleropyrrolidine (C-60-diFc) were synthesized and characterized. The effects of the covalent linkage of fullerene[60] and the insertion of a phenyl group between fullerene[60] and diferrocenyl propane (diFc) moiety on the thermodynamic stability, the magnetic properties and the band structure were studied through measurements of the temperature-dependent magnetic susceptibility and cyclic voltammetry. The results show that both the covalent linkage of fullerene[60] and the insertion of a phenyl linker between fullerene[60] and diferrocenyl propane moiety lead to a weakness in the antiferromagnetic interaction between the two ferrocenyl entities. The introduction of C-60 leads to an increase in the thermodynamic stability of the diferrocenyl propane moiety. The insertion of phenyl group between C-60 and diFc or between C-60 and Fc decreases the thermodynamic stability, and result in an increase in the HOMO orbital energies, but lead to a decrease in the HOMO-LUMO gap. The above experimental results lay the foundation for the future design of novel functional materials that can be applied to molecular devices. (C) 2017 Elsevier B.V. All rights reserved.