Fig. 1: Structures of the cyanopyrene isomers.
From: Detections of interstellar aromatic nitriles 2-cyanopyrene and 4-cyanopyrene in TMC-1
CN functionalization of pyrene (C16H10) forms three possible isomers (C17H9N), namely, 1-cyanopyrene (1-CN–C16H9), 2-cyanopyrene (2-CN–C16H9) and 4-cyanopyrene (4-CN–C16H9). Equivalent sites are shown with coloured circles.
