Two-Step Synthesis, Structure, and Optical Features of a Double Hetero[7]helicene

Abstract

A novel double aza-oxa[7]helicene was synthesized from the commercially available N1,N4-di(naphthalen-2-yl)benzene-1,4-diamine and p-benzoquinone in two steps. Combining the acid-mediated annulation with the electrochemical sequential reaction (oxidative coupling and dehydrative cyclization) afforded this double hetero[7]helicene. Moreover, the structural and optical features of this molecule have been studied using X-ray crystallographic analysis, and the absorption and emission behaviors were rationalized based on DFT calculations.

Impact of helical elongation of symmetric oxa[n]helicenes on their structural, photophysical, and chiroptical characteristics

“…For the anisotropy of the induced current density (AICD) simulations, the AICD‐3.0.4 software was used 53 . The enantiomerization barriers were studied using MN15 as a functional and 6‐311G(d,p) as a basis set 54 . TD‐DFT calculations were performed directly on cartesian coordinates obtained from the crystal structures of oxa[ n ]helicenes at MN15/6‐311G(d,p)/PCM = chloroform level of theory and on those optimized at the lowest energy singlet excited state (S 1 ) 55 .…”

“…53 The enantiomerization barriers were studied using MN15 as a functional and 6-311G(d,p) as a basis set. 54 TD-DFT calculations were performed directly on cartesian coordinates obtained from the crystal structures of oxa[n]helicenes at MN15/6-311G(d,p)/PCM = chloroform level of theory and on those optimized at the lowest energy singlet excited state (S 1 ). 55 The electric and magnetic transition dipole moments of OH5, OH7, and OH9 were calculated by Multiwfn 56 and visulaized using VMD software.…”

“…Helicenes are ortho ‐fused polycyclic aromatic hydrocarbons in which the aromatic rings are angularly annulated to give them their characteristic helical scaffold 1–3 . This unique structure with an extended π‐conjugated system and inherent chirality imparts various desirable electronic, photophysical, and chiroptical properties, including circular dichroism (CD) and circularly polarized luminescence (CPL) 4–6 . Exploiting these advantages, helicenes have found applications in diverse material fields, such as molecular sensors, 7,8 chiral switches, 9 bioimaging, quantum computers, and displays 10 .…”

“…including circular dichroism (CD) and circularly polarized luminescence (CPL). [4][5][6] Exploiting these advantages, helicenes have found applications in diverse material fields, such as molecular sensors, 7,8 chiral switches, 9 bioimaging, quantum computers, and displays. 10 Extensive efforts have been devoted to enhancing the optical properties of helicenes, with a focus on studying the impact of structural modifications on these properties.…”

Synthesis and Structural and Optical Behavior of Dehydrohelicene-Containing Polycyclic Compounds

“…The key distinction between hetero[ n ]dehydrohelicenes and their carbo- analogs lies in the incorporation of one or more heteroatoms into the dehydrohelicene scaffolds. This modification results in the modulation of their physical and optical characteristics, consequently altering electronic properties and expanding their utility [ 65 , 66 , 67 ]. Despite the promising potential in various applications, it is crucial to recognize that the realm of hetero[ n ]dehydrohelicene chemistry represents a relatively recent and burgeoning area of research.…”