Starre anellierte Kohlenstoff‐Schwefel‐Strukturen

Noncovalent Interactions in the Asymmetric Synthesis of Rigid, Conjugated Helical Structures

“…[6,7] Helical structures derived from conjugated ortho-annelated aromatic rings, known as [n]helicenes, are precisely defined at the molecular level. [8][9][10][11] For [n]helicenes with a sufficiently large number of aromatic rings (n), rigid conformations with large barriers to racemization and enhanced molecular chiroptical properties may be expected. [11a, 12, 13] Diverse electronic structures for such helices may result from various aromatic rings [11ab-19] or by introducing antiaromatic rings [20] to the structure, to obtain materials with a wide range of band gaps, 2-4 eV.…”

“…[11a, 12, 13] Diverse electronic structures for such helices may result from various aromatic rings [11ab-19] or by introducing antiaromatic rings [20] to the structure, to obtain materials with a wide range of band gaps, 2-4 eV. [11a,b, 17, 20, 21] Although significant progress has been made in the synthesis of [n]helicenes, the preparation of such highly annelated and strained p-systems, [11] especially by asymmetric synthesis, [16,17,[22][23][24] remains a challenge. The development of new synthetic strategies for the preparation of precisely defined and extended helical structures, as well as under-standing the factors that control the structure and properties of these molecules, are crucial to making progress in the area of rigid helical motifs.Herein, we demonstrate the important role of noncovalent interactions in the asymmetric synthesis of rigid, conjugated helical structures.…”

FT Raman and DFT Study on a Series of All‐anti Oligothienoacenes End‐Capped with Triisopropylsilyl Groups

“…[1,2] Oligothienoacenes, the fused-ring analogues of a-linked oligothiophenes that resemble acenes, are of particular interest as conjugated materials due to their outstanding electronic properties and environmental stability. [2,3] Because of their rigid architecture, oligothienoacenes are not hampered by the conformational defects in the solid state from which their nonfused counterparts may suffer. Furthermore, oligothiophenes and acenes such as pentacene commonly display a herringbone packing arrangement in the solid state, which is predicted to hinder charge-carrier mobility due to the nonoptimal p-p overlap.…”

Molecular, Crystal, and Thin‐Film Structures of Octathio[8]circulene: Release of Antiaromatic Molecular Distortion and Lamellar Structure of Self‐Assembling Thin Films

“…Takuya Fujimoto, Rie Suizu, Hirofumi Yoshikawa, and Kunio Awaga* [a] Carbon-sulfur compounds [1] have been studied extensively as key materials in organic/molecular electronics. A variety of poly-and oligothiophenes have been synthesized by organic synthesis and electrochemistry to elucidate their electronic properties.…”