Homo and Hetero Molecular 3D Nanographenes Employing a Cyclooctatetraene Scaffold

Two novel homo and
hetero three-dimensional nanographenes, NG1 and NG2, featuring a cyclooctatetraene core
are designed, synthesized, and characterized. A concise and efficient
bottom-up methodology was employed during which 24 new carbon–carbon
bonds were formed. By means of a Scholl reaction nanographenes with
53 fused rings are realized, which exhibited good solubility in common
organic solvents. The resulting saddle-like structures of NG1 and NG2 are electron-rich and show good chemical and
electrochemical stability. Their molecular structures are fully elucidated
by single-crystal X-ray crystallography. From their crystal structure
analysis is concluded that both nanographenes are chiral and crystallize
as a racemic mixture. Our work was rounded-off by excited state investigations
such as electron and energy transfer with electron-acceptors and -donors.