Structural and Photophysical Properties of a Cd(II) Coordination Polymer Based on Mixed Aromatic Ligands: A Combined Experimental and Theoretical Study

A novel one-dimensional Cd(II) coordination polymer (CP) based on mixed aromatic ligands was synthesized and characterized by X-ray diffraction, thermogravimetric analysis and spectroscopic analyses. Fingerprint plots in Hirshfeld surface analysis illustrate that the one-dimensional crystal structure of the CP is stabilized by C-H center dot center dot center dot O, pi center dot center dot center dot pi, C-H center dot center dot center dot pi, and H center dot center dot center dot H intermolecular interactions. The structural and photophysical properties of the CP were then investigated by time-dependent density functional theory methods, and computational results well reproduced the experimental data. The combined investigations found a ligand-to-ligand charge transfer character during the electrons relax from the first singlet excited(1) state of the CP. The weak fluorescence of CP could be resulted from the energy interlacing of the frontier molecular orbitals (FMOs) of aromatic ligands and the fulfilled d (10) configuration of Cd(II). Herein, this CP exhibits as a potential tunable luminescent sensor by adjusting the energy levels of the FMOs of aromatic ligands.