Dynamic dual spectral response on different cations by regulating PET and LMCT process of a simple luminescent sensor

A simple luminescent sensor BOPM-AB based on arylmaleimide (AM) with 4-methoxyphenyl and N, N-dimethylamino group was designed and synthesized. BOPM-AB exhibits dual spectra response of absorption and emission on Hg2+, Cu2+ and Fe3+. Interestingly, a dynamic response of BOPM-AB was observed upon the stimulus of Cu2+ or Fe3+. With the prolongation of interaction time, Cu2+ and Fe3+ make the emission of BOPM-AB become stronger and weaker, respectively. Titration experiments and DFT calculations demonstrate that the dynamic spectra response is closely related to two transfer process: photoinduced electron transfer (PET) from the N, N-dimethylamino to AM, and ligand metal charge transfer (LMCT) induced by metal ions. The unique of properties of BOPM-AB imposes it huge potential in the field of molecular operation. Combined with the factors of different loading amount, sequence of ions and coordinating time, two complex sequential logic systems (half-adder, and keypad lock) could be constructed based on BOPM-AB.