On the Physicochemical Properties of Pyridohelicenes

• Published in: Chemistry : a European journal Vol. 20; no. 3; pp. 877 - 893
• Main Authors: Vacek Chocholoušová, Jana, Vacek, Jaroslav, Andronova, Angelina, Míšek, Jiří, Songis, Olivier, Šámal, Michal, Stará, Irena G., Meyer, Michel, Bourdillon, Mélanie, Pospíšil, Lubomír, Starý, Ivo
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 13-01-2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc; Wiley-VCH Verlag
• Subjects: Barriers; basicity; Chemical Sciences; Chemistry; chirality; Constants; cyclic voltammetry; density functional calculations; helical structures; helicenes; Inversions; Kinetics; Mathematical analysis; or physical chemistry; Organic chemistry; Protonation; Theoretical and; Thermal cycling; Titration; Voltammetry; density functional calculations; basicity; chirality; cyclic voltammetry; helicenes; helical structures
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201204410

A comprehensive study on the physicochemical properties of a series of mono‐ and diaza[5]helicenes as well as mono‐ and diaza[6]helicenes is reported. Through the use of both computational and experimental methods, these helically chiral pyridohelicenes with the nitrogen atom(s) in various positions are characterised according to their inversion barriers, protonation constants and redox potentials. By using DFT calculations, kinetic measurements, UV/Vis titrations, cyclic voltammetry and EPR spectroscopy, a self‐contained picture of their behaviour under conventional treatment by heat, acids and oxidising/reducing agents is provided.
Helically chiral aromatics: The physicochemical properties of a series of pyrido[5]‐ and pyrido[6]helicenes and their protonated forms were calculated and measured, including their inversion and racemisation barriers, protonation constants and redox properties (see figure).