Synthesis and Characterization of a Dysprosium(III)–Iron(III) Heterodinuclear Complex: Crystallographic, Hirshfeld Surface, Density-Functional Theory, and Luminescence Analyses

Here, a new cyano-bridged 3d–4f compound, a Dy(III)–Fe(III) molecular assembly ([Dy(DMF)4(H2O)3(μ-CN)Fe(CN)5.H2O] (1)), having a structure consisting of neutral one-dimensional (1D) chains, as well as an unbound aqua molecule, was synthesized and characterized using single crystal X-ray diffraction (XRD), infrared (IR), and elemental analyses. We then examined its structural topologies and studied its density functional theory (DFT), Hirshfeld surface analyses, and photophysical properties. The 1D chains were further linked by H-bond interactions, generating a three-dimensional (3D) motif which stabilizes the whole molecule. The weak interactions in 1 were assessed using Hirshfeld surface analyses, as well as fingerprint plots and DFT studies. Additionally, Hirshfeld surface analysis was performed to elucidate the roles of the weak interactions, such as the H⋯H, C⋯H, C–H⋯π, and van der Waals (vdW) interactions which are pivotal to stabilizing the crystal environment. Furthermore, the DFT studies were used to elucidate the bonding structure within the complex system. Complex 1 exhibits characteristic fluorescence as the Dy(III) complex is an excellent lime green luminescent material. Thus, it is considered to be a suitable material for preparing photoluminescent material.