Synthesis, crystal structures and two-photon absorption properties of triphenylamine cyanoacetic acid derivative and its organooxotin complexes.

Three novel organooxotin complexes (Z1, Z2 and Z3) were synthesized by reaction of L1 (2-cyano-3-(4-(diphenylamino)phenyl) acrylic acid) with n-Bu2SnO, Ph3Sn(OH) and nBu6Sn2O. The structures of the three complexes have been confirmed by single-crystal X-ray diffraction analysis. The metal complex Z1 features a ladder framework while Z2 and Z3 show discrete structures. The UV-vis absorption, single-photon excited fluorescence (SPEF) and two-photon excited fluorescence (2PEF) of the complexes have been systematically studied, suggesting that the three metal complexes have strong two-photon absorption (2PA) and large 2PA cross-sections. It is noteworthy that Z2 possesses an enhanced two-photon absorption, and Z3 exhibits larger 2PA cross-section per molecular weight compared to L1. Finally, high anti-tumor activity of these three metal complexes has also been identified.