One-step assembly of Pd-Keggin-polyoxometalates for catalytic benzothiadiazole generation and derived cell-imaging probe application

One-step assembly of organic-ligand modified Pd-Keggin-POMs has been rarely reported, so as for their applications in catalytic benzothiadiazole generation and derived cell-imaging probing. Herein, three Pd-Keggin-POMs (compounds 1–3) have been successfully synthesized via a one-step assembly strategy. Thus-obtained Pd-Keggin-POMs with well-defined structures and heterogeneous properties enable highly efficient catalytic benzothiadiazole generation. Specifically, compound 3 showed outstanding catalytic activities in Suzuki-Miyaura coupling reactions for the generation of benzothiadiazole derivatives (yields, 90%-97%) and was represented as one of the best catalysts reported to date. Consequently, the obtained benzothiadiazoles were used as the bio-probe for tracking lipid droplets in living-cells and exhibited large Stokes shifts (130 nm), low cytotoxicity and good targeting, which could be also applied to mark the distribution of LDs in living HeLa cells. Systematic investigations clearly decipher the functions of Pd-Keggin-POMs toward finding novel bio-probe materials, highlighting a new insight into the generation of sustainable materials in life-science.