The capability of Co-DHBDC or CoCl2 to undergo photothermal activation, dominated by the wavelength of light used, has enabled us to explore light-assisted orthogonal synthesis. Thus, in order to shed more light on the photothermal reaction mechanism, and due to the versatile options offered by the photothermal heating, our interest naturally leaned towards photo-switching experiments achieved simply by toggling the light source during reactions. We firstly started by analyzing the photothermal reactions in time dependent manner and compared with conventional heating. When employing conventional heating, Co-DHBDC nanorods typically formed within 1-2 hours (Fig. and). However, under photothermal conditions, the resulting MOF's morphological characteristics were contingent upon the specific wavelength utilized. Namely, rod-shaped Co-DHBDC structures were exclusively obtained through photothermal activation with a 660 nm LED, whereas at 520 nm assemblies of Co-DHBDC were obtained after 1 h reaction (Fig. and). This discrepancy is attributed to the varying effects of photothermal heating, as elaborated in Fig. . The rod-shaped Co-DHBDC MOF structures produced via 660 nm photothermal activation measured approximately 1600×400 nm, larger than those formed under regular heating conditions (≈450×80 nm) with similar reaction conditions except for light irradiation (Fig. and, and Supplementary Figs. . Meanwhile, the assembly generated through 520 nm activation measured approximately 3200×2300 nm, featuring individual nanorods protruding at an approximate width of 150-200 nm (Fig. ).