TY  - THES
U1  - Dissertation oder Habilitation
A1  - Kondinski, Aleksandar
T1  - On the Isomer Problem of Mixed−Addenda and Heterogroup−Substituted Polyoxometalates
N2  - Polyoxometalates (POMs) represent nanoscale metal−oxide clusters, conventionally constructed of early transition metals in high oxidation states (mainly V, Mo and W). POMs exhibit tunable physicochemical properties, which make them suitable for applications in catalysis, magnetism and preparation of nanostructured materials. The properties of POMs are predominantly tuned by the number, the type and by the arrangement of the involved building blocks in unique structural architectures. The stabilities and the properties rising from the arrangement of the building blocks define the problem of POM isomerism. In this thesis, density functional theory (DFT) and its time-dependent implementation (TD-DFT) are applied to shed light into the isomer problem of mixed−addenda and heterogroup−substituted POMs. The following problems were addressed: (i) Elucidation of the solution structure of the two reported polyoxoaurates [Au4Se4O16]4− and [Au4As4O16]8−. (ii) Understanding of the positional isomerism problem and structure-stability relationship in the mixed-addenda [NaAuxPd12–xAs8O40](x−15) and [NaAuxPd12–xSe8O32](x−7) polyoxoanions. (iii) Structure-stability relationship of the isomeric α–/γ–/β–[V14E8O50]12− and α–/γ–/β–[V14E8O42X8]12− (E = Si, Ge and Sn; X = S, Se and Te) heteropolyoxovanadates. (iv) Comparative study of the arsenate capped polyoxopalladates [Na2Pd22As16O76]26– and [Pd13As8O40]14–. (v) Study of anti–/syn–[Pt2(PW11O39)2]10− and their two electron oxidized species anti–/syn– [Pt2(H2O)2(PW11O39)2]8−.
AB  - Polyoxometalates (POMs) represent nanoscale metal−oxide clusters, conventionally constructed of early transition metals in high oxidation states (mainly V, Mo and W). POMs exhibit tunable physicochemical properties, which make them suitable for applications in catalysis, magnetism and preparation of nanostructured materials. The properties of POMs are predominantly tuned by the number, the type and by the arrangement of the involved building blocks in unique structural architectures. The stabilities and the properties rising from the arrangement of the building blocks define the problem of POM isomerism. In this thesis, density functional theory (DFT) and its time-dependent implementation (TD-DFT) are applied to shed light into the isomer problem of mixed−addenda and heterogroup−substituted POMs. The following problems were addressed: (i) Elucidation of the solution structure of the two reported polyoxoaurates [Au4Se4O16]4− and [Au4As4O16]8−. (ii) Understanding of the positional isomerism problem and structure-stability relationship in the mixed-addenda [NaAuxPd12–xAs8O40](x−15) and [NaAuxPd12–xSe8O32](x−7) polyoxoanions. (iii) Structure-stability relationship of the isomeric α–/γ–/β–[V14E8O50]12− and α–/γ–/β–[V14E8O42X8]12− (E = Si, Ge and Sn; X = S, Se and Te) heteropolyoxovanadates. (iv) Comparative study of the arsenate capped polyoxopalladates [Na2Pd22As16O76]26– and [Pd13As8O40]14–. (v) Study of anti–/syn–[Pt2(PW11O39)2]10− and their two electron oxidized species anti–/syn– [Pt2(H2O)2(PW11O39)2]8−.
KW  - Polyoxometalate
KW  - Density functional theory (DFT)
KW  - Isomerism
KW  - Noble metals
KW  - Polyoxovanadates
Y1  - 2016
U6  - https://nbn-resolving.org/urn:nbn:de:gbv:579-opus-1004465
UN  - https://nbn-resolving.org/urn:nbn:de:gbv:579-opus-1004465
ER  -