Synthesis, crystal structures, photophysical properties, and bioimaging of living cells of bis-β-diketonate phenothiazine ligands and its cyclic dinuclear complexes

摘要

Two bis-β-diketones, RCOCH_2CO-EPTZ-COCH_2COR (EPTZ = 10-ethylphenothiazine; R = C_6H_5 for H _2L~1 and CF3 for H_2L~2) and their cyclic dinuclear Zn(II), Cd(II), Ni(II), Mn(II), Cu(II), Co(II) complexes have been synthesized and fully characterized. Their crystal structures were determined by single crystal X-ray diffraction analysis. Their photophysical properties have been further investigated both experimentally and theoretically. The results revealed that significant enhancement of two-photon absorption cross section values were obtained for the cyclic dinuclear Zn(II) and Cd(II) complexes compared with their free ligands. Additionally, confocal microscopy and two-photon microscopy fluorescent imaging of MCF-7 cells labeled with two ligands and Zn(II) complexes reveal their potential applications as a biological fluorescent probe.