C–C bond formation through oxidatively induced elimination of platinum complexes—A novel approach towards conjugated macrocyclesElectronic supplementary information (ESI) available: experimental section. See http://www.rsc.org/suppdata/cc/b3/b300542a/

Fuhrmann, Gerda; Debaerdemaeker, T.; Bäuerle, Peter

doi:10.1039/b300542a

Cited by 143 publications

(64 citation statements)

References 24 publications

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“…Interestingly, cyclo [8]thiophene 74 b, which may be viewed as an all-thia analogue of 73-R 8 , is a redcolored compound. [255] The macrocycle of 74 b, which is most likely very strained (t F = 0.70), is the smallest reported member of the cyclo[n]thiophene family discussed in Section 9.3.…”

Section: T0 Systemsmentioning

confidence: 99%

“…Even though the family of cyclo[n]thiophenes (74 b, 117 a-126 a) [255,275,276,280] is seldom discussed in the context of porphyrinoid chemistry, these unusual macrocycles can be regarded as heteroanalogues of cyclo[n]pyrroles. Unlike the latter class of compounds, of which only three representatives have been reported (29-H 4 , 56-H 5 , 72-H 6 with n = 6, 7, 8), cyclo[n]thiophenes, synthesized using carefully designed metal-mediated coupling reactions, can be obtained in a spectacular variety of molecular sizes ranging from octa-to tetracontamers (Scheme 26).…”

Section: Cyclo[n]thiophenesmentioning

confidence: 99%

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Figure Eights, Möbius Bands, and More: Conformation and Aromaticity of Porphyrinoids

2011

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The aromatic character of porphyrins, which has significant chemical and biological consequences, can be substantially altered by judicious modifications of the parent ring system. Expansion of the macrocycle, which is achieved by introducing additional subunits, usually increases the so-called free curvature of the ring, leading to larger angular strain. This strain is reduced by a variety of conformational changes, most notably by subunit inversion and p surface twisting. The latter effect creates a particularly convenient access to Möbius aromatic molecules, whose properties, predicted over 40 years ago, are of considerable theoretical importance. The conformational processes occurring in porphyrin analogues are often coupled to other chemical phenomena, and can thus be exploited as a means of constructing functional molecular devices. In this Review, the structural chemistry of porphyrinoids is discussed in the context of their conformational dynamics and p-electron conjugation.

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Section: T0 Systemsmentioning

confidence: 99%

Section: Cyclo[n]thiophenesmentioning

confidence: 99%

Figure Eights, Möbius Bands, and More: Conformation and Aromaticity of Porphyrinoids

2011

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“…[39] Normalerweise wird diese Verbindung in Form ihres Sulfatsalzes [72a-H 8 ][SO 4 ] isoliert (Schema 23). Sie ist der wichtigste Vertreter aus der Cyclopyrrol-Familie mit mögli-chen Anwendungen in der molekularen Elektronik, [258] für Flüssigkristalle, [259] für die Detektion von Sprengstoffen [259] [255] Sein höchstwahr-scheinlich stark gespannter Makrocyclus (t F = 0.70) ist der kleinste in der ganzen Cyclo[n]thiophen-Familie (siehe Abschnitt 9.3).…”

Section: T0-systemeunclassified

Figure‐Eight‐Strukturen, Möbius‐Bänder und mehr: Konformation und Aromatizität von Porphyrinoiden

2011

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Der aromatische Charakter von Porphyrinen, der signifikante chemische und biologische Auswirkungen hat, kann durch gezielte Modifikationen des Stammringsystems beträchtlich verändert werden. Zusätzliche Untereinheiten expandieren den Makrocyclus und erhöhen seine Ringkrümmung, was zu einer höheren Winkelspannung führt. Diese Winkelspannung kann der Ring durch eine Reihe von Konformationsänderungen wieder abbauen, insbesondere durch Invertieren von Untereinheiten und Verdrillen (twisting) der π‐Oberfläche. Letzterer Effekt bietet einen Zugang zu Möbius‐aromatischen Molekülen, deren Eigenschaften, gleichwohl vor über 40 Jahren vorausgesagt, unter theoretischen Aspekten von großer Bedeutung sind. Häufig gehen Konformationsprozesse in den Porphyrinanaloga mit anderen chemischen Phänomenen einher, sodass sie für den Aufbau von molekularen Funktionseinheiten verwendet werden können. In diesem Aufsatz wird die Strukturchemie der Porphyrinoide im Zusammenhang mit ihrer Konformationsdynamik und elektronischen π‐Konjugation diskutiert.

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“…Finally, it is important to point out that both Eqs. (6) and (7) differ from the empirical expression for semiconducting carbon nanotubes 73,74 [E g = 0.84/d (nm), where d is the diameter of a nonmetallic nanotube] since each of our expressions have a constant energy term implying that cyclic oligothiophene nanotubes are always semiconducting and will not give a zero band gap regardless of size. This result is expected since conductivity in these noncovalently bound nanotubes will be ultimately limited by hopping transport between π orbitals of adjacent monomers, which we estimate in Eq.…”

Section: Electronic Band Structuresmentioning

confidence: 99%

“…For example, porphyrin nanotubes are known to self-assemble via strong ionic interactions, 4 and cyclic oligothiophenes have also demonstrated very stable self-assembling properties. 5 Furthermore, recent synthetic advances 6 in the creation of various cyclic oligothiophenes [7][8][9] have opened up the possibility of forming oligothiophene-based nanostructures with specific sizes and chemical functional groups. 10 Compared to conventional carbon nanotubes bonded via strong covalent interactions, cyclic oligothiophene nanotubes are held together along the tube axis via purely noncovalent interactions, lending to facile self-assembly from individual cyclic monomers.…”

Section: Introductionmentioning

confidence: 99%

Self-assembled cyclic oligothiophene nanotubes: Electronic properties from a dispersion-corrected hybrid functional

Wong

2011

Phys. Rev. B

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The band structure and size scaling of electronic properties in self-assembled cyclic oligothiophene nanotubes are investigated using density functional theory. In these unique tubular aggregates, the π -π stacking interactions between adjacent monomers provide pathways for charge transport and energy migration along the periodic one-dimensional nanostructure. In order to simultaneously describe both the π -π stacking interactions and the global electronic band structure of these nanotubes, we utilize a dispersion-corrected Becke three-parameter Lee-Yang-Parr-D (B3LYP-D) hybrid functional in conjunction with all-electron basis sets and one-dimensional periodic boundary conditions. Based on our B3LYP-D calculations, we present simple analytical formulae for estimating the fundamental band gaps of these unique nanotubes as a function of size and diameter. Our results on these molecular nanostructures indicate that all of the oligothiophene nanotubes are direct-gap semiconductors with band gaps ranging from 0.9 to 3.3 eV, depending on tube diameter and oligothiophene orientation. These nanotubes have cohesive energies of up to 2.43 eV per monomer, indicating future potential use in organic electronic devices due to their tunable electronic band structure and high structural stability.

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C–C bond formation through oxidatively induced elimination of platinum complexes—A novel approach towards conjugated macrocyclesElectronic supplementary information (ESI) available: experimental section. See http://www.rsc.org/suppdata/cc/b3/b300542a/

Cited by 143 publications

References 24 publications

Figure Eights, Möbius Bands, and More: Conformation and Aromaticity of Porphyrinoids

Figure Eights, Möbius Bands, and More: Conformation and Aromaticity of Porphyrinoids

Figure‐Eight‐Strukturen, Möbius‐Bänder und mehr: Konformation und Aromatizität von Porphyrinoiden

Self-assembled cyclic oligothiophene nanotubes: Electronic properties from a dispersion-corrected hybrid functional

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