Fullerene C60 dianion salt, (Me4N+)2(C602−)·(TPC)2·2C6H4Cl2, where TPC is triptycene, obtained by a multicomponent approach

Abstract

A multicomponent approach provided a new salt (Me₄N⁺)₂(C₆₀²⁻)·(TPC)₂·2C₆H₄Cl₂ (1) containing the discrete C₆₀²⁻ dianions, where TPC is triptycene. The crystal structure consists of alternating layers of closely packed zigzag fullerene chains solvated with C₆H₄Cl₂ molecules and the TPC network with Me₄N⁺ cations. The hexagonal vacancies in the TPC network accommodate the cations and simultaneously act as a template for the formation of zigzag fullerene chains. Optical spectra support the formation of C₆₀²⁻ dianions. According to the electron paramagnetic resonance technique (EPR) the C₆₀²⁻ dianions have a diamagnetic singlet ground state below 140 K. The increased intensity of the EPR signal above this temperature reflects the growing thermal population of the excited triplet state. This signal has g = 2.0003 and a linewidth of 2.53 mT at 302 K and the estimated singlet–triplet energy gap is 674 ± 10 K (468 ± 7 cm⁻¹).