Ring destruction and carbide formation in niobium–PAH complexes

Gas phase complexes between niobium atoms and the polycyclic aromatic hydrocarbons (PAHs) pyrene (C16H10) and coronene (C24H12) are produced in a molecular beam using laser vaporization in a pulsed nozzle cluster source. Cation complexes are studied with time-of-flight mass spectrometry and mass-selected photodissociation. Mass distributions and fragmentation patterns for Nbx–(PAH)y complexes are significantly different from those found previously for other Mx–(PAH)y complexes. Masses indicating the formation of metal–hydrocarbons and metal–carbides are prominent. Larger complexes add intact PAH moieties to the strongly bound mono-metal adducts. Niobium is significantly more reactive with PAH species than other transition metals studied to date.