Two-dimensional coordination polymers based on functionalized chiral binaphthyl-derived ligands with phosphine oxide groups and zinc(II) and cadmium(II) ions

Two-dimensional coordination polymers Zn2L2 (1) and Cd2L2·DMF·2H2O (2) (DMF = dimethylformamide) were synthesized under solvothermal conditions by the reactions between rigid dicarboxylate ligand containing two phosphine oxide groups, (S)-4,4′-bis(4-carboxyphenyl)-2,2′-bis(diphenylphosphinoyl)-1,1′-binaphthyl (H2L), and the Zinc(II) and Cadmium(II) salts. The complexes were characterized by single-crystal X-ray diffraction, infrared spectra (IR), elemental analyses, thermogravimetric analyses (TGA), and photoluminescent studies. Complexes 1 and 2 are isomorphous, while 2 contains different guest molecules with one DMF and two waters. Luminescent properties investigation shows that complexes 1 and 2 have red-shifted 14 nm and 11 nm, respectively, and the luminescence efficiency is also different compared with the free ligand H2L.

Graphical AbstractTwo-dimensional coordination polymers Zn2L2 (1) and Cd2L2·DMF·2H2O (2) with (S)-4,4′-bis(4-carboxyphenyl)-2,2′-bis(diphenylphosphinoyl)-1,1′-binaphthyl (H2L) have been synthesized under solvothermal conditions and characterized by single-crystal X-ray diffraction. The results confirmed that complexes 1 and 2 had red-shifted in luminescence spectrum compared with the free ligand H2L, which was induced by ligand-centered π→π∗ transitions.Figure optionsDownload as PowerPoint slide