The self-assembly of low-molecular weight telechelics equipped with terminal ligands in the presence of stochiometric amounts of a metal salt furnishes metallosupramolecular polymers (MSPs). The properties of MSPs can be altered by stimuli such as heat, light, or mechanical force, which affect the dynamic non-covalent interactions and shift the equilibrium between the assembled and disassembled states. MSPs are therefore intrinsically stimuli-responsive and have been exploited to create functional materials for applications that range from healable surface coatings to mechanically responsive materials to shape-memory polymers. While the majority of MSPs make use of charged metal-ligand complexes, zero-valent metal complexes have remained largely unexplored. Building on previous work with bis(η2-alkyne)platinum(0) complexes as conjugated cross-links in poly(p-phenylene ethynylene)s, we prepared MSPs by linear chain extension of a ditopic diphenylacetylene carrying telechelic core with platinum(0) complexes. This approach afforded soluble and stable MSPs. We demonstrate that such polymers permit the spatially resolved generation of metal nanoparticles (NPs) via decomplexation, nucleation, and growth without requiring a reduction step. A study of the temperature-dependence of the complex dissociation showed that the MSPs are stable under ambient conditions, but undergo an irreversible decomplexation above a threshold temperature. A characterization of heated films by means of differential scanning calorimetry, small angle X-ray scattering, and high-resolution transmission electron microscopy showed that the Pt-complexes dissociate, covalent cross-links of the polymer form, and 1 nm-sized clusters of Pt-atoms are obtained. Upon annealing at 200°C, Pt-NPs with diameters between 1 and 3 nm form. The NPs are homogenously distributed throughout the cross-linked polymer matrix, rendering such materials potentially interesting for applications that range from catalysis, to sensing and optoelectronic applications.

Stimuli-responsive Pt(0)-containing metallosupramolecular polymers

256th National Meeting (2018)

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