A novel bi-layered samarium complex with an unprecedented coordination mode of orotic acid [Sm2(HL)2(ox)(H2O)2]n · 2.5nH2O (H3L = orotic acid, ox2− = oxalate2−): Synthesis, crystal structure and physical properties

The first structurally characterized orotato samarium(III) complex, [Sm2(HL)2(ox)(H2O)2]n · 2.5nH2O (1), with a novel bi-layered structure has been synthesized and structurally characterized by X-ray crystallography, in which orotic acid ligands exhibit two coordination modes of μ3-η2κO,O′:η2κO′,N:η1κ″ and μ4-η2κO,O′:η2κO′,N:η1κ″:η1κO‴ for HL2− with the latter being novel coordination mode. The temperature dependence of the magnetic susceptibilities of the title complex reveals that the title complex follow the Curie–Wiess paramagnetic behavior down to 5 K. The title complex exhibits strong luminescent emissions based on the f–f transitions of Sm(III) ion and 4G5/2 lifetime.