A new nickel complex [Ni(dpyb)2 ](NO3)2 ·(H2 O)3 was synthesized by means of solvent-thermal synthesis using 2,6-bis(2-pyrazinyl)-3,4′-bipyridine (dpyb), which is one of polynitrogen compounds, as the ligand and Ni(NO3)3 ·6H2 O as raw materials. The structure of the complex [Ni(dpyb)2 ](NO3)2 ·(H2 O)3 was characterized by X-ray single crystal diffraction, infrared spectroscopy and Raman spectroscopy. The results of structural analysis show that the complex was a mononuclear structure, and the mononuclear structure is further extended to the binuclear structure through intermolecular hydrogen bonds between the mononuclear units. The Hirshfeld surface analysis of the target complex was carried out using Crystal Explorer 21 software, and the results show that there is strong hydrogen bonding in the structure of [Ni(dpyb)2] (NO3)2 ·(H2 O)3. The frontline molecular orbitals and energy band gaps of the free ligand and the complex were also calculated by Gaussian 09W and Gauss View 5. 0 software using the B3LYP/6-311G (d, p) method, and the results suggest that the complex has high chemical stability. The results of the computational study are in good agreement with the experiments. In addition, fluorescence analysis of the free ligand and complexe were performed, and the results indicate that compared with the free ligand, the fluorescence intensity of the complex is weakened, which is due to the coordination between the ligand and the Ni(II) ion. [ABSTRACT FROM AUTHOR]