Lack of atrans-cisoidphase incis-polyacetylene

Wu, Chao; Miao, Jun; Yu, Jun

doi:10.1103/physrevb.57.6

Cited by 15 publications

(3 citation statements)

References 28 publications

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“…The same is not true for the cis isomer of Figure c but, nevertheless, here also the C−C bond lengths may alternate giving either the cis−trans isomer of Figure d or the trans-cis isomer of Figure e. Of these, the cis−trans isomer is the stabler form (see, e.g., ref and references therein). (As is common practice, we shall here refer to the systems of Figures a−b as trans isomers and those of Figures c−e as cis isomers.)…”

Section: Section 1 Introductionmentioning

confidence: 82%

Structural and Electronic Properties of Fluorinated and Chlorinated Polyacetylene

Springborg

1999

J. Am. Chem. Soc.

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Using a density-functional method we have calculated the electronic and structural properties of infinite and periodic (CF) x , (CCl) x , and (CFCCl) x chains. Only for the (CF) x and (CCl) x trans isomers without a C−C bond-length alternation we have optimized the structure completely and subsequently explored whether the total energy for these isomers could be lowered upon a such alternation. Finally, we studied the electronic properties of different cis isomers with fixed structures as well as of trans and cis isomers of (CFCCl) x . Special emphasis is put on whether these newly synthesized materials have properties resembling those of most other conjugated polymers, i.e., whether π orbitals from mainly carbon functions are those closest to the Fermi level and whether a bond-length alternation exists. We find that the F-substituted materials in many respects are similar to the unsubstituted ones (with, however, smaller differences), but that the Cl-substituted ones differ significantly from the unsubstituted ones. The trans isomers of the systems with mixed substitutions possess properties that are intermediate between those of the F- and the Cl-substituted ones. On the other hand, the cis isomers of (CFCCl) x have markedly different properties and are the only ones with F/Cl nearest neighbors. A comparison with the experimental information suggests that for (CFCCl) x the trans isomer is the one that is synthesized. Finally, we predict that only for (CF) x will solitons or polarons be generated upon doping.

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Section: Section 1 Introductionmentioning

confidence: 82%

Structural and Electronic Properties of Fluorinated and Chlorinated Polyacetylene

Springborg

1999

J. Am. Chem. Soc.

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“…[11] Thei mportance of NÀH···p interactions as ac onformation-defining element is discussed and adetailed analysis of the electronic structure is offered. [11] Thei mportance of NÀH···p interactions as ac onformation-defining element is discussed and adetailed analysis of the electronic structure is offered.…”

mentioning

confidence: 99%

“…Herein, we describe the first synthesis of conjugated azaborine oligomers and ac orresponding polymer.T hey are designed to be regioregular to minimize steric interactions between side chains and ensure optimal p-conjugation along the conjugated backbone.W ed iscuss the discovery of an unexpected and strong preference for a syn arrangement, which is reminiscent of that of the elusive trans-cisoid form of poly(acetylene) (PA). [11] Thei mportance of NÀH···p interactions as ac onformation-defining element is discussed and adetailed analysis of the electronic structure is offered.…”

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confidence: 99%

Regioregular Synthesis of Azaborine Oligomers and a Polymer with a syn Conformation Stabilized by NH⋅⋅⋅π Interactions

Baggett

Guo

et al. 2015

Angewandte Chemie

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The regioregular synthesis of the first azaborine oligomers and ac orresponding conjugated polymer was accomplished by Suzuki-Miyaura coupling methods.A n almost perfectly coplanar syn arrangement of the heterocycles was deduced from an X-ray crystal structure of the dimer, which also suggested that N À H···p interactions play an important role.C omputational studies further supported these experimental observations and indicated that the electronic structure of the longer azaborine oligomers and polymer resembles that of poly(cyclohexadiene) more than poly(pphenylene). Ac omparison of the absorption and emission properties of the polymer with those of the oligomers revealed dramatic bathochromic shifts upon chain elongation, thus suggesting highly effective extension of conjugation.

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Regioregular Synthesis of Azaborine Oligomers and a Polymer with a syn Conformation Stabilized by NH⋅⋅⋅π Interactions

et al. 2015

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The regioregular synthesis of the first azaborine oligomers and a corresponding conjugated polymer was accomplished by Suzuki-Miyaura coupling methods. An almost perfectly coplanar syn arrangement of the heterocycles was deduced from an X-ray crystal structure of the dimer, which also suggested that NH⋅⋅⋅π interactions play an important role. Computational studies further supported these experimental observations and indicated that the electronic structure of the longer azaborine oligomers and polymer resembles that of poly(cyclohexadiene) more than poly(p-phenylene). A comparison of the absorption and emission properties of the polymer with those of the oligomers revealed dramatic bathochromic shifts upon chain elongation, thus suggesting highly effective extension of conjugation.

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Lack of atrans-cisoidphase incis-polyacetylene

Cited by 15 publications

References 28 publications

Structural and Electronic Properties of Fluorinated and Chlorinated Polyacetylene

Structural and Electronic Properties of Fluorinated and Chlorinated Polyacetylene

Regioregular Synthesis of Azaborine Oligomers and a Polymer with a syn Conformation Stabilized by NH⋅⋅⋅π Interactions

Regioregular Synthesis of Azaborine Oligomers and a Polymer with a syn Conformation Stabilized by NH⋅⋅⋅π Interactions

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