Solvothermal Syntheses And Characterizations Of Chalcogenidoarsenates And Chalcogenidoantimonates

The solvothermal reaction in ethylene polyamine solutions had proven to be a versatile route to the synthesis of p group chalcogenidometalates containing the transition metal or lanthanide metal complexes. The ethylene polyamine acts as not only the solvent of the reaction, but also the ligand to the transition metals or lanthanide metals, so the ethylene polyamine plays an important role on the formation and structures of the chalcogenidometalates. In the thesis the Ln/As/Se, Ln/Sb/S and Ln/Sb/Se (Ln = lanthanide) synthetic systems in ethylene polyamine were investigated under mild solvothermal conditions. The selenidoarsenates and selenidoantimonates containing lanthanide metal complexes with mixed ethylene polyamine were synthesized for the first time from the Ln/As/Se and Ln/Sb/Se systems. The effects of lanthanide size and ethylene polyamine on the corrodination modes of [AsSe₄]^3-, [SbS4]^3- and [SbSe₄]^3- anions were investigated. Series of lanthanide selenidoarsenates were prepared, and the [AsSe₄]^3- ion can be controlled to coordinate with the lanthanide metal ions (Ln³⁺) by using different ethylene polyamines as the second ligands. In this work, the major studies and results as follows:1. The lanthanide selenidoarsenates [Ln(en)3(H2O)(μ-η1,η1-AsSe₄)] (Ln = La (1a), Ce (1b)) and [Ln(en)4]AsSe₄·0.5en (Ln = Gd (2a), Dy (2b)), [Ln(dien)2(μ-η1,η2-AsSe₄)](Ln = La(3a), Ce (3b), Pr (3c)), [La(en)(trien)(μ-η1,η2-AsSe₄)] (4a) and [Sm(en)(trien)(η2-AsSe₄)](4b) were prepared by solvothermal reaction in en, dien and mixed en/trien solvents respectively. Comparing the crystal structures, the coordination modes of the [AsSe₄]^3- anion to Ln³⁺ ions were not only related with the lanthanide ions, but also were much influenced by the ethylene polyamines.2. The lanthanide thioantimonates [Ln(dien)2(μ-η1,η2-SbS4)]∞(Ln = La (5a), Ce (5b)) were synthesized by solvothermal method in dien solvent.3. The lanthanide selenidoantimonates [Ln(en)(trien)(μ-η1,η2-SbSe₄)]∞(Ln = Ce (6a), Nd (6b)) and [Sm(en)(trien)(η2-SbSe₄)](6c) were synthesized by solvothermal method in en/trien mixed solvents. Comparison of different crystal structures, the coordination modes of the [SbSe₄]^3- anion were not only related with the lanthanide ions, but also were much influenced by the ethylene polyamines.4. The synthesized chalcogenidometalates were characterized by elemental analysis, IR and X-ray crystallographic, and their thermal stability and optical properties were also investigated.