Intermolecular bond stability of C60 dimers and 2D pressure-polymerized C60

TL;DR

This study investigates the thermal stability and transformation processes of C60 dimers and 2D pressure-polymerized C60, revealing activation energies and comparing expansivity to other polymerized forms.

Contribution

It provides detailed thermally activated process data for C60 dimers and 2D polymerized C60, expanding understanding of their stability and properties.

Findings

Activation energies: 1.75 eV for dimers, 1.9 eV for 2D polymerized C60.

2D polymer phase has expansivity close to diamond.

Transformation back to normal C60 follows a simple thermally activated process.

Abstract

The thermal stability of C60 dimers and 2D pressure-polymerized C60 is studied using high-resolution capacitance dilatometry. The transformation of both the dimer and the polymer phases back to 'normal' C60 is excellently described by a simple thermally activated process, with activation energies of 1.75 1 0.1 eV (dimer) and 1.9 1 0.2 eV (polymer). These results are compared to previous data of 1D-polymerized C60 and photo-polymerized C60. The thermal expansivity of the 2D-polymer phase is as much as a factor of ten smaller than that of pure C60 and approaches values for diamond.