Synthesis, Supramolecular Insight, Hirshfeld Surface Analyses and Magnetic Properties of Two Lanthanide Complexes of 1,8-naphthalene Dicarboxylate

Two isostructural mononuclear complexes of lanthanides (Ln = La and Pr) constructed from 1,8-naphthalene dicarboxylate (NDC) and 1,10-phenanthroline (Phen) as auxiliary ligand are reported. Both the complexes were formed through an in situ hydrolytic ring opening reaction of 1,8-naphthalic anhydride with Phen ligands. 3D supramolecular structures are observed which are guided by different weak interactions. The crystal structures of both the complexes were determined by single crystal X-ray diffraction. The room temperature photoluminescence studies, carried out in the powder state displayed three noticeable peaks from excited (3PJ; J = 2, 1, and 0) to ground state (3H4) at ~464 nm, 497 nm, and 538 nm, respectively, under UV excitation. Temperature dependent dc susceptibility (χ = M/H) as a function of temperature is investigated where Pr-complex shows antiferromagnetic behaviour. The Hirshfeld surface analysis of the two complexes is also described.