A Carbon Nanotube Binding BODIPY-C₆₀ Nano Tweezer: Charge Stabilization through Sequential Electron Transfer

Electron donor-acceptor (DA) hybrids comprised of single-wall carbon nanotubes (SWCNTs) are promising functional materials for light energy conversion. However, the DA hybrids built on SWCNTs have failed to reveal the much-sought long-lived charge separation (CS) due to the close proximity of the DA entities facilitating charge recombination. Here, we address this issue and report an elegant strategy to build multi-modular DA hybrids capable of producing long-lived CS states. For this, a nano tweezer featuring V-shape configured BODIPY was synthesized to host SWCNTs of different diameters via pi-stacking. Supported by spectral, electrochemical, and computational studies, the established energy scheme revealed the possibility of sequential electron transfer. Systematic pump-probe studies covering wide spatial and temporal scales provided evidence of CS from the initial (BODIPY)-B-1* ultimately resulting in C-60(center dot-)-BODIPY-SWCNT center dot+ CS states of lifetimes in the 20-microsecond range.