Triphenylamine-anthraquinone based donor-acceptor conjugated microporous polymers for photocatalytic hydroxylation of phenylboronic acids

Triphenylamine-based donor-acceptor conjugated microporous polymers, namely PTPA-AQ and PTPA-AM, were synthesized for the first time via Suzuki-Miyaura coupling of tris(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-amine as a donor with 2,6-dibromoanthracene-9,10-dione and 2,2 '-(2,6-dibromoanthracene-9,10-diylidene)dimalononitrile acceptors for efficient visible-light driven oxidative hydroxylation of various phenylboronic acids. The dimalononitrile derivative having greater acceptor ability showed tunable photophysical properties of PTPA-AM (lower band gap of 1.47 eV and better exciton separation efficiency) as well as porosity (lower Brunauer-Emmett-Teller (BET) surface area of 43 m(2) g(-1)). PTPA-AQ having higher BET surface area (400 m(2) g(-1)), suitable HOMO-LUMO positions and an optimal band gap (1.94 eV) showed better photocatalytic activity for the hydroxylation with yields up to 96%.