Conjugated one and two dimensional polymers

doi:10.1098/rspa.1979.0037

Cited by 396 publications

(49 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chemical bonding results from orbital interactions that have the effect of reducing the atomic charges to some extent. The effect that this has on the electrostatic potential was estimated using extended Hiickel, tight-binding calculations of cation-substituted phyllosilicates (Hoffmann and Lipscomb, 1962;Hoffmann, 1963;Whangbo et al, 1979;Bleam and Hoffmann, 1988). The critical point is that without orbital interactions, cation substitution produces a point defect, whereas with orbital interactions, the defect is a localized charge array.…”

Section: Methodsmentioning

confidence: 99%

The Nature of Cation-Substitution Sites in Phyllosilicates

Bleam

1990

Clays and clay miner.

View full text Add to dashboard Cite

Abstract--A fundamental property of electrostatic potentials is their additivity. This study demonstrates that the electrostatic potential of a negatively charged, cation-substituted phyllosilicate layer can be represented as the sum of two potentials. Viewing cation substitution as a defect, one potential is derived from the atoms in a charge-neutral, unsubstituted layer such as pyrophyllite or talc. The "'neutral-layer" potential rapidly decays to zero with distance from the layer and is determined primarily by the atoms in the first two atomic planes parallel to the (001) surface, i.e., the basal oxygens and tetrahedral cations. The second component, characterized as a "defect" potential, is a long-range potential derived from cation-substitution. The model used to compute the electrostatic potentials, a two-dimensional Ewald lattice sum, represents the atoms of a single phyllosilicate layer as point charges.

show abstract

Section: Methodsmentioning

confidence: 99%

The Nature of Cation-Substitution Sites in Phyllosilicates

Bleam

1990

Clays and clay miner.

View full text Add to dashboard Cite

show abstract

“…8). This can also be demonstrated with many different conjugated polymers, and even with noncarbon conjugated connectors such as in carbazidyl sesquisulphide (CN 2 S) 41 (Fig. 8).…”

mentioning

confidence: 99%

Dirac Cones in two-dimensional conjugated polymer networks

et al. 2014

View full text Add to dashboard Cite

Linear electronic band dispersion and the associated Dirac physics has to date been limited to special-case materials, notably graphene and the surfaces of three-dimensional (3D) topological insulators. Here we report that it is possible to create two-dimensional fully conjugated polymer networks with corresponding conical valence and conduction bands and linear energy dispersion at the Fermi level. This is possible for a wide range of polymer types and connectors, resulting in a versatile new family of experimentally realisable materials with unique tuneable electronic properties. We demonstrate their stability on substrates and possibilities for doping and Dirac cone distortion. Notably, the cones can be maintained in 3D-layered crystals. Resembling covalent organic frameworks, these materials represent a potentially exciting new field combining the unique Dirac physics of graphene with the structural flexibility and design opportunities of organic-conjugated polymer chemistry.

show abstract

“…The combination of electrical and magnetic properties observed for 11 is typical of a Mott insulator [57][58][59], in which the unpaired spins are localized due to dominance of the Coulomb interaction U over the transfer integral t. Thus the magnetic data are well described in terms of a one dimensional S = 1/2 antiferromagnetic Heisenberg chain with J = 6.3 cm −1 ( Figure 7) [55]. The non-metallic character of the conductivity (Figure 8) would then be result of the localization of unpaired electrons due to their Coulombic repulsion as a result of the large intermolecular separation [57][58][59].…”

Section: Band Electronic Structure Of 11mentioning

confidence: 99%

Synthesis, Structure and Solid State Properties of Cyclohexanemethylamine Substituted Phenalenyl Based Molecular Conductor

et al. 2012

View full text Add to dashboard Cite

Abstract:We report the preparation, crystallization and solid state characterization of a cyclohexanemethylamine substituted spirobiphenalenyl radical; in the solid state the compound is iso-structural with its dehydro-analog (benzylamine-substitued compound), and the molecules packed in a one-dimensional fashion that we refer to as a π-step stack. Neighboring molecules in the stack interact via the overlap of one pair of active (spin bearing) carbon atoms per phenalenyl unit. The magnetic susceptibility measurement indicates that in the solid state the radical remains paramagnetic and the fraction of Curie spins is 0.75 per molecule. We use the analytical form of the Bonner-Fisher model for the S = 1/2 antiferromagnetic Heisenberg chain of isotropically interacting spins with intrachain spin coupling constant J = 6.3 cm −1 , to fit the experimentally observed paramagnetism [χ p (T)] in the temperature range 4-330 K. The measured room temperature conductivity (σ RT = 2.4 × 10 -3 S/cm) is comparable with that of the iso-structural benzyl radical, even though the calculated band dispersions are smaller than that of the unsaturated analog.

show abstract

Conjugated one and two dimensional polymers

Cited by 396 publications

References 27 publications

The Nature of Cation-Substitution Sites in Phyllosilicates

The Nature of Cation-Substitution Sites in Phyllosilicates

Dirac Cones in two-dimensional conjugated polymer networks

Synthesis, Structure and Solid State Properties of Cyclohexanemethylamine Substituted Phenalenyl Based Molecular Conductor

Contact Info

Product

Resources

About