Polysilane-pyrazoline hybrid synthesized via mechanochemically assisted hydrosilylation: Structural and optical insights for optoelectronic applications

• Solvent-minimized mechanochemical route to polysilane–pyrazoline copolymer (PSTP). • Efficient Pt-catalyzed hydrosilylation under ambient grinding conditions. • Structural confirmation by FTIR, 1 H-NMR, GPC-MALS, UV-Vis, and fluorescence. • Dual light harvesting and Förster resonance energy transfer demonstrated. • Thermal stability (∼207 °C) supports potential in optoelectronic applications. This study reports the synthesis of a polysilane-pyrazoline hybrid polymer ( PSTP ) through a mechanochemically assisted hydrosilylation process carried out under solvent-free conditions. Triphenylpyrazoline was efficiently grafted onto poly[diphenyl-co-methyl(H)]silane ( PSH ) using a platinum-based catalyst by grinding the solid reactants under anhydrous conditions. While a trace amount of xylene was introduced via the catalyst solution (Pt ∼ 2% in xylene), the total solvent usage was maintained below the accepted threshold for mechanochemical synthesis (η ≤ 1 µL/mg). The reaction produced high yields (>70%) with minimized side reactions typically associated with conventional hydrosilylation method. Detailed characterization using FTIR, 1 H-NMR, GPC-MALS, UV-Vis, and fluorescence spectroscopy confirmed the successful formation of PSTP with unique optical properties. The optical characterization revealed dual light-harvesting behavior consistent with a Förster Resonance Energy Transfer (FRET) mechanism from the polysilane backbone to the pyrazoline units. Computational analysis supported these observations and provided insights into the excited-state transitions. The polysilane backbone serves as the energy donor, while the pyrazoline derivative acts as the energy acceptor, resulting in efficient fluorescence emission. This innovative hybrid material exhibits promising optical properties, making it a potential candidate for optoelectronic devices, such as light-emitting diodes and optical sensors. The combination of a sustainable synthesis process, robust material characterization, and advanced optical functionality establishes PSTP as a versatile platform for future optoelectronic applications.