Synthesis of platinum(ii)-complex end-tethered polymers: spectroscopic properties and nanostructured particles

Although metal-containing polymers have been widely studied as a novel class of functional soft materials, the microphase separation between polymeric segments and metal-ligand complexes has been less addressed, which is critical to control their structures and functions. To do this, short-chain polystyrenes (PSs) have been end-functionalized with nanosized square-planar platinum(ii) complexes. The platinum(ii)-comprising polymers were found to show significant luminescence enhancement in chloroform/methanol solvent mixtures upon increasing the methanol composition. By modulating both the PS length and solvent quality, various self-assembled morphologies formed controllably in the mixed solvents and typical examples include nanofibers, nanoellipsoids, and nanospheres. More interestingly, the inside structures of these polymer particles are shown to be lamellar with sub-10 nm spacings, wherein the PS blocks are alternatively aligned with the platinum(ii) units. Such a luminescence enhancement and hierarchical nanostructured particles originate from a subtle combination of directional Pt(ii)MIDLINE HORIZONTAL ELLIPSISPt(ii) and/or p-p stacking interactions between the platinum(ii) units and the solvophobic effect between the PS blocks. This work suggests that by microphase separating polymer chains with nanosized metal-ligand complexes, metal-containing polymers can self-assemble to form sub-10 nm scale nanostructures showcasing desired properties and functions.

Automated summary

Metal-containing polymers have great potential as functional soft materials, but the microphase separation between polymeric segments and metal-ligand complexes has not been well explored. This study focuses on the use of short-chain polystyrenes (PSs) functionalized with nanosized platinum(ii) complexes to control the structures and functions of metal-containing polymers. The results show that by manipulating the polymer length and solvent quality, various self-assembled nanostructures can be formed, and the inside structures of these polymer particles are lamellar with sub-10 nm spacings. This work suggests that metal-containing polymers can self-assemble to form sub-10 nm scale nanostructures with desired properties and functions.