Hydrosoluble aliphatic tertiary amine-containing hyperbranched polysiloxanes with bright blue photoluminescence

Dendritic and hyperbranched poly(amidoamines) are the first covered and most investigated photoluminescent polymers carrying unconventional chromogens, and studies reveal that the oxidation or acidification of the N-branched tertiary amine in these compounds is responsible for the light emission. Here, we report the synthesis and photoluminescence properties of novel hydrosoluble aliphatic tertiary amine-containing hyperbranched polysiloxanes (TAHPSi). The as-prepared polymers are fabricated by a mild one-step transesterification reaction using raw materials, including tetraethoxysilane (TEOS), triethanolamine (TEA), N-methyldiethanolamine (NMDEA) and diethylene glycol (DEG). Amusingly, the resultant products, without any treatment, such as oxidation or acidification, can still produce bright blue fluorescence under a UV light, and our rudimentary study manifests that the terminal hydroxyl group plays a key role in forming blue-fluorescent species. In addition, the significant concentration and pH-dependent profiles of luminescence intensity are also observed. Moreover, the TAHPSi can be used to detect metal ions, and there is strong selective quenching in respect of Fe³⁺. Therefore, the TAHPSi show promise as Fe³⁺ probes.