Pyromellitic Diimide-Based Donor–Acceptor MOF with Panchromatic Absorption for High-Efficiency Photothermal Conversion

The incorporation of donor–acceptor components into metal–organic frameworks (MOFs) is an effective approach for developing efficient near-infrared (NIR) photothermal conversion materials; yet, their precise structural design and synthetic methodologies still present significant challenges. In this work, we present a distinctive MOF material Zn 2 (bpPDI)(TTFTB)·solvent ( MOF 1 ) constructed by the coordinated assembly of donor–acceptor components, featuring a tetrathiafulvalene tetrabenzoate (TTFTB) electron donor and a bis-pyridyl-substituted pyromellitic diimide (bpPDI) electron acceptor. The material demonstrates significant intrinsic intermolecular electron-transfer capability and possesses a long-lived TTFTB •+ radical cation and a bpPDI •– radical anion. These characteristics enable panchromatic absorption spanning the visible to the second near-infrared (NIR-II) region, thus allowing efficient NIR photothermal conversion. Under NIR light irradiation, MOF 1 achieves efficient photothermal conversion (Δ T max = 137 °C under 0.5 W cm –2 laser exposure), including rare NIR-II photothermal conversion capabilities, while exhibiting excellent thermal stability and cycling durability.