New yttrium tropolonato-based complexes: synthesis, X-ray crystal structures and thermal properties

Abstract

New yttrium complexes containing HT (tropolone, 2-hydroxy-2,4,6-cycloheptatrien-1-one) and its anion, [Y(H2O)2T3]·0.5H2O, [Y(H2O)2(HT)T2]·NO3·0.5HNO3 and [Y(HT)T3]2, were synthesized and structurally characterized. In all compounds, the coordination number (CN) of yttrium is 8 and the coordination mode is YO8. In reactions with bidentate N-donor ligands, phen (1,10-phenantroline) and Bath (4,7-diphenyl-1,10-phenanthroline), anhydrous, non-hygroscopic, heteroleptic mononuclear complexes [Y(phen)T3] and [Y(Bath)T3]·0.5EtOH with CN = 8 and YO6N2 coordination mode were obtained. During thermolysis of [Y(H2O)2T3]·0.5H2O, the removal of coordinated and solvate water molecules leads to the formation of anhydrous YT3 remaining stable up to 320° C, which is also characteristic of [Y(HT)T3]2 thermolysis. Decomposition of tropolonate complexes containing phenanthroline occurs at temperatures >300 °C.