Synthesis, characterization and thermal behaviour of solid-state compounds of 4-methoxybenzoate with some bivalent transition metal ions

Abstract

Solid compounds of general formula LnL<Subscript>3</Subscript> for La and Ce and LnL<Subscript>3</Subscript>&middot;<Emphasis Type=”Italic”>n</Emphasis>H<Subscript>2</Subscript>O for Pr, Nd and Sm where <Emphasis Type=”Italic”>Ln</Emphasis> stands for trivalent lanthanides, <Emphasis Type=”Italic”>L</Emphasis> is 2-chlorobenzylidenepyruvate and <Emphasis Type=”Italic”>n</Emphasis>=2, 3 and 2 respectively, have been synthesized. On heating these compounds decompose in two or five steps. They lose the hydration water in the first step and the thermal decomposition of the anhydrous compounds occurs with the formation of the respective oxide, CeO<Subscript>2</Subscript>, Pr<Subscript>6</Subscript>O<Subscript>11</Subscript> and Ln<Subscript>2</Subscript>O<Subscript>3</Subscript> (<Emphasis Type=”Italic”>Ln</Emphasis>=La, Nd, Sm) as final residue. The dehydration enthalpies found for these compounds (Pr, Nd and Sm) were: 140.1, 148.2 and 221.3 kJ mol<Superscript>-1</Superscript>, respectively.