Three novel spiral chain Nd (III) Eu (III) Sm (III)complexes bridged by 1,1 '(1,4‐phenylene‐bis [methylene])‐bis (pyridine‐3‐carboxylicaicd): Synthesis, structural characterization, and antitumor activity

In this work, three new complexes [Ln2(L)3·H2O]n (where Ln = Nd(1)、Eu (2) and Sm (3)) have been synthesized by H2L (H2L = 1,1 ‘(1,4‐phenylene‐ bis [methylene])‐bis (pyridine‐3‐carboxylicaicd)) and were characterized by X‐ray single crystal diffraction and PXRD. The interaction of these complexes with FS DNA (fish sperm DNA) and the DNA binding constants of the complexes were determined using UV spectroscopy, indicating their ability to bind to FS DNA. The DNA binding constants k of the three complexes were 1.0186 × 104, 5.047 × 103, and 5.115 × 103, respectively. The results of UV spectrum showed that the complex 1–3 was bound to DNA through hydrogen bonding. The interaction of the complexes with FS DNA was studied by fluorescence spectroscopy. The stern‐volmer quenching values of complexes 1, 2, and 3 were 0.186, 0.093, and 0.114, respectively. Electrophoresis experiments showed that the three complexes could cleave DNA molecules. In addition, flow cytometry, and morphological apoptosis studies showed that the complex could induce apoptosis of HeLa tumor cells. Results all the three complexes had potential medicinal value. Three new isomorphic metal complexes [Nd2(L)3·H2O]n, [Eu2(L)3·H2O]n, [Sm2(L)3·H2O]n(H2L = 1,1′(1,4‐phenylene‐bis [methylene])‐bis (pyridine‐3‐carboxy‐ licaicd are novel structures and have favorable ability to induce apoptosis of HeLa cells. They will be used as potential cancer drugs in practical applications to meet the requirements of certain fields.