Self-assembly of tetra nuclear lanthanide (Pr, Nd) hydroxo clusters with functionalized β-diketone: Experimental and theoretical studies

Amenability of functionalized diketonate ligands to stabilize lanthanoid clusters is demonstrated. Two tetra nuclear lanthanide clusters [Ln4(O-DBM)4(HO-DBM)4(µ3-OH)2][Et3NH]2.3CH2Cl2, (Ln = Pr(1),Nd(2)) has been synthesized and structurally characterized. X-ray structure has been optimized theoretically using B3LYP/Gen method level of theory in the gas phase. [Display omitted] Reaction of LnCl3·6H2O (Ln = Pr, Nd) with functionalized β-Diketone {ortho-hydroxydibenzoylmethane (HO-DBM)} in 1:2 ratio in methanol and in presence of triethylamine (excess) as base yielded two tetra nuclear lanthanide hydroxo clusters of composition [Ln4(O-DBM)4(HO-DBM)4(µ3-OH)2][Et3NH]2.3CH2Cl2, (Ln = Pr (1), Nd (2)). The clusters 1 and 2 has been structurally characterized by single crystal X-ray diffraction. A one-dimensional supramolecular chain is observed in the solid state structure (2), where dichloromethane solvent molecules are linked to the phenyl rings of adjacent diketone linkers through CH⋯π and Cl⋯π interactions. Theoretical studies support the stability of structure (2), with calculated geometric parameters aligning with experimental findings.