Solution‐Phase Synthesis and Isolation of An Aza‐Triangulene and Its Cation in Crystalline Form. (5th September 2022)

• Record Type: Journal Article
• Authors: Wei, Haipeng; Hou, Xudong; Xu, Tingting; Zou, Ya; Li, Guangwu; Wu, Shaofei; Geng, Yanhou; Wu, Jishan
• Is Part Of: Angewandte Chemie. Volume 134:Number 40(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-05
• Subjects: Heteroatom Doping -- Polycyclic Hydrocarbon -- Radical -- Triangulene -- Zwitterionic; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202210386
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Synthesis of triangulene and its derivatives is challenging due to their intrinsic high spin nature. Herein, we report solution‐phase synthesis and isolation of a nitrogen‐doped triangulene (i.e., aza‐triangulene) (NT ) and its cation (NT + ) in single‐crystal form. Notably, the cation NT + can be regarded as an isoelectronic structure of the corresponding all‐carbon triangulene. Both NT and NT + show reasonable stability due to kinetic blocking by bulky and electron‐withdrawing aryl substituents, and intramolecular donor‐acceptor interaction. Bond length analysis, magnetic measurements and theoretical calculations reveal that the neutral NT has a doublet ground state with a zwitterionic character, while the cation NT + exhibits a triplet ground state with a singlet‐triplet energy gap of +0.84 kcal mol −1 . This study provides a rational strategy to access high‐spin systems by heteroatom doping of pure π‐conjugated polycyclic hydrocarbons. Abstract : A nitrogen‐doped triangulene and its cation were synthesized and isolated in crystalline form. The cation is an isoelectronic structure of triangulene, showing a triplet ground state with a singlet‐triplet energy gap of about 0.84 kcal mol −1 .