A Dipleiadiene‐Embedded Aromatic Saddle Consisting of 86 Carbon Atoms. (10th January 2018)

• Record Type: Journal Article
• Authors: Pun, Sai Ho; Chan, Chi Kit; Luo, Jiye; Liu, Zhifeng; Miao, Qian
• Is Part Of: Angewandte Chemie. Volume 130:Number 6(2018)
• Page Start: 1597
• Page End: 1602
• Publication Date: 2018-01-10
• Subjects: Arene -- Nanographene -- Polycyclen -- Stereochemie; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201711437
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: This study presents a new type of negatively curved nanographene (C86 H32 ) that contains an unprecedented pattern of heptagons. A tert ‐butylated derivative of C86 H32 was successfully synthesized using tetrabenzodipleiadiene as a key building block. This synthesis involved a ring expansion reaction as a key step to form the seven‐membered rings in the framework of tetrabenzodipleiadiene. The single‐crystal structure reveals a saddle‐shaped molecule with a highly bent naphthalene moiety at the center of the polycyclic backbone. As found from the DFT calculations, this aromatic saddle is flexible at room temperature and has a saddle‐shaped geometry as the dominant conformation. The DFT calculations along with experimental results show that the attachment of t ‐butyl groups to the central tetrabenzodipleiadiene moiety of nanographene C86 H32 can stabilize the saddle conformation and make this nanographene less flexible.