Spirobifluorene-BINOL-based microporous polymer nanoreactor for efficient 1H-tetrazole synthesis and iodine...

Porous polymeric nanoreactors capable of multitasking are attractive and require a judicious design strategy. Herein, we describe an unusual approach for the synthesis of a porous polymer SBF-BINOL-6 by in situ formation of the BINOL entity taking substituted naphthols and spirobifluorene as co-monomers with high yield (81%). The as-synthesized polymer exhibited nanotube and nanosphere-like morphology, thermal endurance up to 372 °C and a BET surface area as high as 590 m² g^-1. The polymer endowed efficient loading of silver nanoparticles to generate Ag@SBF6, as confirmed from X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. Ag@SBF6 was effectively used as a heterogeneous catalyst towards the [3 + 2] dipolar cycloaddition reaction for the synthesis of biologically important 5-substituted 1H-tetrazoles with yields in the range of 75-99% and recyclability for at least seven times without a significant decline in its catalytic efficiency. Additionally, a superior host-guest interaction by the polymer offered iodine adsorption in the vapour phase with a high uptake capacity of up to 4.0 g g^-1. Interestingly, the iodine-loaded polymer, I2@SBF6, demonstrated iodine-promoted increased conductivity (1.3 × 10^-3 S cm^-1) through facile charge transfer interactions.