Two bimetallic compounds with attractive structures and properties

Abstract

Two new bimetallic lanthanide-mercury isonicotinic acid compounds were successfully synthesized through classical hydrothermal reactions using DyCl3·6H2O or LuCl3·6H2O, HgCl2, isonicotinic acid, and distilled water. The resulting compounds, [Dy2(IA)6(H2O)2(H3O)2(Hg2Cl5)2]n(3nHgCl2) (1; IA refers to isonicotinic acid anions) and [Lu(HIA)(IA)2(H2O)2Hg2Cl5]2n[3n(HgCl2)]·6nH2O (2; HIA refers to isonicotinic acid), exhibit intriguing crystal structures and photophysical properties. The crystal structures of compounds 1 and 2 were determined through single crystal X-ray diffraction, revealing their two-dimensional (2D) nature. Compound 1 displays upconversion yellow photoluminescence, attributed to the 4F9/2 → 6H13/2 electronic transition of the trivalent dysprosium ion. In contrast, compound 2 exhibits blue photoluminescent emission. The Commission Internationale de I'Éclairage (CIE) chromaticity coordinates of (0.4874, 0.5115) for 1 and (0.1225, 0.0678) for 2. The correlated color temperatures (CCT) are 2960 K and 5503 K for compounds 1 and 2, respectively. Furthermore, the semiconductor band gaps for compounds 1 and 2, determined by solid-state diffuse reflectance experiments, are 2.92 eV and 4.75 eV, respectively. Additional insights into their thermal stability are provided via thermogravimetric analysis (TG) results.