Sökning: "lone pairs"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden lone pairs.

  1. 1. Transition metal oxofluorides comprising lone pair elements Synthesis and Characterization

    Detta är en avhandling från Stockholm : Department of Materials and Environmental Chemistry (MMK), Stockholm University

    Författare :Shichao Hu; Stockholms universitet.; [2014]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lone pairs; oxofluorides; low-dimensional compounds; oorganisk kemi; Inorganic Chemistry;

    Sammanfattning : Within the family of transition metal oxochlorides/bromides containing lone pair elements, the transition metal cations often adopt a low-dimensional arrangement such as 2D layers, 1D chains or 0D clusters. The reduced dimensionality is attributed to the presence of stereochemically active lone pairs which are positioned in the non-bonding orbital and will not participate in bond formation and instead act as structural spacers that help to separate coordination polyhedra around transition metal cations from forming three dimensional networks. LÄS MER

  2. 2. A new synthetic strategy for low-dimensional compounds Lone pair cations and alkaline earth spacers

    Detta är en avhandling från Stockholm : Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi

    Författare :Rie Takagi Fredrickson; Stockholms universitet.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Alkaline earth; Lone pair elements; Low-dimensional compounds; NATURAL SCIENCES Chemistry Inorganic chemistry; NATURVETENSKAP Kemi Oorganisk kemi; oorganisk kemi; Inorganic Chemistry;

    Sammanfattning : Complex transition metals oxyhalides containing a lone pair element, such as tellurium (IV), form an attractive research field because there is a high probability of finding new low-dimensionally arranged compounds and, particularly, a low-dimensionally arranged transition metals substructures, leading to interesting physical properties. Tellurium (IV) can drive the formation of many unusual structures because of its stereochemically active lone pair electrons, E. LÄS MER

  3. 3. The Role of Tetrahedral Building Blocks in Low-Dimensional Oxohalide Materials

    Detta är en avhandling från Stockholm : Department of Materials and Environmental Chemistry (MMK), Stockholm University

    Författare :Iwan Zimmermann; Stockholms universitet.; [2014]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lone-pair elements; crystal structure; low-dimensional compounds; oxohalides; oorganisk kemi; Inorganic Chemistry;

    Sammanfattning : The structural architecture found in low-dimensional materials can lead to a number of interesting physical properties including anisotropic conductivity, magnetic frustration and non-linear optical properties. There is no standard synthesis concept described thus far to apply when searching for new low-dimensional compounds, and therefore control on the design of the new materials is of great importance. LÄS MER

  4. 4. "Chemical scissors" - a shortcut to the low-dimensional world

    Detta är en avhandling från Stockholm : Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi

    Författare :Zuzana Hugonin; Stockholms universitet.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lone-pair of electrons; Low-dimensional compounds; Antimony oxo-halides; NATURAL SCIENCES Chemistry Inorganic chemistry; NATURVETENSKAP Kemi Oorganisk kemi; oorganisk kemi; Inorganic Chemistry;

    Sammanfattning : A number of oxo-halide compounds have been prepared and studied. The antimony Sb3+ cation shows great flexibility in adopting coordination numbers of three or four, and, since this ion carries a stereochemically active lone-pair of electrons (E), both coordinations are one-sided. LÄS MER

  5. 5. Terminating species and Lewis acid-base preference in oxohalides – a new route to low-dimensional compounds

    Detta är en avhandling från Stockholm : Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi

    Författare :Richard Becker; Stockholms universitet.; [2007]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Low dimensionality; crystal structures; tellurites; selenites; oxohalides; NATURAL SCIENCES Chemistry Inorganic chemistry; NATURVETENSKAP Kemi Oorganisk kemi;

    Sammanfattning : This thesis is based upon synthesis and structure determination of new transition metal oxo-halide compounds, which includes p-element cations that have a stereochemically active lone pair. A synthesis concept has been developed, which uses several different structural features to increase the possibility to yield a low-dimensional arrangement of transition metal cations. LÄS MER