Truxene-based covalent organic polyhedrons constructed through alkyne metathesis

Abstract

Dynamic alkyne metathesis has successfully been employed toward the synthesis of shape-persistent macrocycles and covalent organic polyhedrons (COPs). In this contribution, we present two newly designed COPs, TC1 and TC3, based on truxene moieties. Specifically, COPs were successfully synthesized under open air conditions within 2 h upon heating at 55 °C with a highly active multidentate molybdenum catalyst. The fluorescent nature of truxene inspired the photoluminescence (PL) titration experiments, which demonstrate the host–guest complexation of fullerenes and the truxene based COPs with a high binding constant of 10⁵ M⁻¹. DFT calculations reveal that the C₇₀@TC1 complexation is exothermic with an enthalpy change of −102.7 kJ mol⁻¹. These findings suggest that the truxene-based COPs can function as discrete fullerene acceptors, whose complexation is driven by the thermodynamics of the system. Such donor–acceptor complexation systems can potentially be used in the development of artificial photosynthetic systems and optoelectronic applications.