Discovery of the Seven-ring Polycyclic Aromatic Hydrocarbon Cyanocoronene (C 24 H 11 CN) in GOTHAM Observations of TMC-1

Abstract We present the synthesis and laboratory rotational spectroscopy of the seven-ring polycyclic aromatic hydrocarbon (PAH) cyanocoronene (C 24 H 11 CN) using a laser-ablation-assisted cavity-enhanced Fourier transform microwave spectrometer. A total of 71 transitions were measured and assigned between 6.8 and 10.6 GHz. Using these assignments, we searched for emission from cyanocoronene in the Green Bank Telescope (GBT) Observations of TMC-1: Hunting Aromatic Molecules project observations of the cold dark molecular cloud TMC-1 using the 100 m GBT. We detect a number of individually resolved transitions in ultrasensitive X -band observations and perform a Markov Chain Monte Carlo analysis to derive…

• NS
  National Science Foundation

  Awards: 1908576, 2307137, AST-2307137, 2205126
• AA
  Arnold and Mabel Beckman Foundation
• SF
  Schmidt Family Foundation
• NI
  National Institute of Standards and Technology
• CS
  Canadian Space Agency
• NS
  Natural Sciences and Engineering Research Council of Canada