Fluorescent poly(boron enaminoketonate)s: synthesis via the direct modification of polyisoxazoles obtained from the click polymerization of a homoditopic nitrile N-oxide and diynes

Abstract

Fluorescent poly(boron enaminoketonate)s (PBEKs) were synthesized via the polycycloaddition of a homoditopic nitrile N-oxide to diynes followed by other polymer reactions. Click polycycloaddition of the nitrile N-oxide to various diynes effectively produced polyisoxazoles in high yields. The polyisoxazoles were transformed into the corresponding fluorescent PBEKs by forming the poly(β-aminoenone) intermediates and reacting these intermediates with (C6F5)2BF·OEt2. The solution and solid-state optical properties of the PBEKs were evaluated by ultraviolet–visible (UV–vis) and fluorescence spectroscopy. Fluorescent poly(boron enaminoketonate)s (PBEKs) were synthesized via polycycloaddition of homoditopic nitrile N-oxide to diynes and subsequent polymer reactions. Click polycycloaddition of the nitrile N-oxide to various diynes effectively produced polyisoxazoles in high yields. Transformation of the polyisoxazoles afforded the corresponding fluorescent PBEKs via intermediary formation of poly(β-aminoenone) followed by the reaction with (C6F5)2BF·OEt2. The optical properties of PBEKs were evaluated by the UV–vis and fluorescent spectra obtained under solution and solid states.