Fig. 2. Synthesis of porphyrin-fused nanographene oligomers as model compounds.
a, Synthetic route to f-P1Ng1, f-P2Ng1 and f-P3Ng2. COD, 1,5-cyclooctadiene; DMF, N,N-dimethylformamide; DDQ, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; TfOH, trifluoromethanesulfonic acid; DCM, dichloromethane. b, DFT-optimized geometry of f-P3Ng2a (M,M,M,M configuration), showing the twisted edge structure, the molecular size and the distance between two porphyrin centres.