Hydrothermal synthesis, crystal structure and luminescence of two new 2D coordination polymers [Ln(IN)(CO ₃)(H ₂O)] (LnLa, Eu) constructed by interesting flat lanthanide carbonate layers

Hydrothermal reactions of lanthanide(III) oxide, isonicotinic acid, methanoic acid at 170°C lead to two new lanthanide carbonate frameworks[Ln(IN)(CO ₃)(H ₂O)] (LnLa (1), Eu (2); HINisonicotinic acid). Compounds 1 and 2 feature a two-dimensional (2D) architecture constructed by the intergrowth of infinite lanthanide carbonate layers. The enhanced fluorescence intensity of 2 indicates the effective energy transfer from the ligand to the Eu ³⁺ center.