Multifunctionality and cytotoxicity of a layered coordination polymer

Abstract

This work reports the synthesis and multifunctionality of 2D layered coordination polymers formulated as [Ln₂(H₃nmp)₂]·xH₂O (1, where Ln = Sm³⁺, Eu³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺ and Y³⁺) (x = 1 to 4). We describe detailed synthesis of the materials using various methods [typical hydrothermal reaction (HT), microwave-assisted synthesis (MWAS) and one-pot method (OP)], while discussing the various crystal morphologies which can be fine tuned by varying systematically the conditions. We further explore the multifunctionality of this material by studying its heterogeneous catalytic activity in the ring opening of styrene oxide, its photoluminescence behaviour and its cytotoxicity. A conversion of 88%/100% yield at 4 h/24 h reaction respectively, with excellent selectivity towards 2-methoxy-2-phenylethanol product (100%) was observed. Photoluminescence properties of the optically-active [Eu₂(H₃nmp)₂]·xH₂O (1Eu) and the mixed-lanthanide [(Gd_0.95Eu_0.5)₂(H₃nmp)₂]·xH₂O (1GdEu), on the other hand, show potential use for UV-to-visible light converters, with lifetimes of 2.31 ± 0.01 and 2.61 ± 0.01 ms at ambient temperature for 1Eu and 1GdEu samples. Preliminary cytotoxic studies showed no effects on metabolic activity of both in vitro human epithelial kidney (HK-2) and human hepatocellular carcinoma (HepG2) cell lines. A reduction of NR uptake was, however, observed indicating some cytotoxic effect on lysosomal activity.