Halogen-Bonded Assemblies of Arylene Imides and Diimides: Insight from Electronic, Structural, and Computational Studies.
Chemistry
; 26(46): 10607-10619, 2020 Aug 17.
Article
em En
| MEDLINE
| ID: mdl-32428280
ABSTRACT
Halogen-bonding interactions in electron-deficient π scaffolds have largely been underexplored. Herein, the halogen-bonding properties of arylene imide/diimide-based electron-deficient scaffolds were studied. The influence of scaffold size, from small (phthalimide) to moderately sized (pyromellitic diimide or naphthalenediimides) to large (perylenediimide), axial-group modification, and number of halo substituents on the halogen bonding and its self-assembly was probed in a set of nine compounds. The structural modification leads to tunable optical and redox properties. The first reduction potential E 1 / 2 1 ranges between -1.09 and -0.17â
V (vs. SCE). Two of the compounds, that is, 6 and 9, have deep-lying LUMOs with values reaching -4.2â
eV. Single crystals of all nine systems were obtained, which showed Brâ
â
â
O, Brâ
â
â
Br, or Brâ
â
â
π halogen-bonding interactions, and a few systems are capable of forming all three types. These interactions lead to halogen-bonded rings (up to 12-membered), which propagate to form stacked 1D, 2D, or corrugated sheets. A few outliers were also identified, for example, molecules that prefer C-Hâ
â
â
O hydrogen bonding over halogen bonding, or noncentrosymmetric rather than centrosymmetric organization. Computational studies based on Atoms in Molecules and Natural Bond Orbital analysis provided further insight into the halogen-bonding interactions. This study can lead to a predictive design tool-box to further explore related systems on surfaces reinforced by these weak directional forces.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Chemistry
Assunto da revista:
QUIMICA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Índia