Browsing by Author "Chilufya, Langson"

Now showing 1 - 2 of 2

Hydrothermal Synthesis and Characterization of Tungsten Oxide Containing Organic-Inorganic Hybrid Material
(Izmir Institute of Technology, 2019) Chilufya, Langson; Emirdağ Eanes, Mehtap; Eanes, Mehtap; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Importance and a wide area of applications of solid-state oxides are well known. Metal oxides crystallize in wide variety but simple structures. Lately general opinion is that piezoelectric, ferromagnetic and catalytic properties of simple oxide structures will be improved if the metal oxides could have more complicated and detailed crystal structures. Therefore, research interest increased towards synthesizing complicated crystal structures. One of the methods to increase the complexity of the structure is the modification of inorganic oxides with organic ligands to synthesize complex hybrid materials. There are a great number of organic-inorganic hybrid materials with Keggin or Lindqvist Polyoxometalates structure containing Molybdenum and Tungsten. Usually Obtaining multifunctional hybrid materials, mostly requires grafting an organic functionalized group into the lacunary Keggin structures [XM11O39](n+4)-. Only Tungsten containing polyoxometalates can form a stable lacunary Keggin structures. A Lindqvist structures [M6O19]2- can also self-assemble with organic dyes to form a stable hybrid materials which have important applications. These polyoxotungstates, as an inorganic building blocks, were combined with organic compounds to obtain organic-inorganic hybrid materials. The carboxylic acid functionalized organotin grafted lacunary Keggin structure was coupled with different amines using N, N’-dicyclohexylcarbodiimide (DCC). Another hybrid material was formed by the association of the Lindqvist POM with phosphine based BODIPY derivative dye. The synthesized compounds were all characterized by SEM, FT-IR, TGA and Powder XRD. Since one of the organic moiety use was a BODIPY-type organic dye, the fluorescence properties of these newly synthesized compounds were investigated.
Hydrothermal Synthesis, Characterization and Catalytic Activities of a Keggin Structure of (4,4′-Bpyh2)3[pw12o40]2•3h2o and a Wells-Dawson Structure of (4,4′-Bpyh2)3(4,4′
(Elsevier, 2025) Ece, Ozlem; Chilufya, Langson; McMillen, Colin D.; Emirdag-Eanes, Mehtap; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Two novel polyoxometalates composed of heteropolytungstates, (4,4 '-bpyH2)3[PW12O40]2 center dot 3H2O (1) and (4,4 '- bpyH2)3(4,4 '-bpyH)1.75[Cu(bpy)2]0.25[H2P2W18O62]2 (2) have been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction and TGA methods. Compound 1 crystallizes in the cubic space group Ia-3with a = 25.9356(12) angstrom, b = 25.936(3) angstrom, c = 25.936(3) angstrom, alpha = 90.00, (3= 90.00, gamma= 90.00 and Z = 8, and compound 2 crystallizes in the triclinic space group P-1with a = 13.5194(17) angstrom, b = 22.400(3) angstrom, c = 27.374(4) angstrom, alpha = 79.833(3), (3= 77.439(3), gamma= 80.213(4) and Z = 2. In addition to structural characterization, the catalytic activities of 1 and 2 were determined in hydrolysis reactions. In the catalytic study, starch hydrolysis reactions were performed by using hydrothermal synthesis, and starch was hydrolyzed successfully at 150 degrees C, 5 h, based on the results of Lugol's test, which highest conversion yields above 90 wt.% under optimum reaction conditions. FT-IR analysis and catalyst reusability tests were also performed for each compound. No appreciable loss was observed in activity after five reaction cycles.