- P. Maier and M. Rösslein
“The B 4∑u– ¬ X 4∑g– Electronic Spectrum of C2+ “
J.Chem.Phys., 88, 4614, 1988.
Identification of the electronic spectrum of this fundamental diatomic cation; implications for a later astronomical search in the diffuse medium.
- Fulara, M. Jakobi and J.P. Maier
“Electronic and Infrared Spectra of C60 Ions in Neon and Argon Matrices”
Chem.Phys.Lett., 211, 227, 1993.
The first well resolved absorption spectrum of C60+ in the near infrared, in a 5 K neon matrix. This enabled astronomers to search for diffuse interstellar bands in this region.
- P. Maier, N.M. Lakin, G.A. H. Walker and D.A. Bohlender
“Detection of C3 in diffuse interstellar clouds”
Astrophys.J., 553, 267, 2001.
As part of the search for the absorptions of linear carbon chains in diffuse clouds based on the gas phase spectra obtained by us in the laboratory, C3 could be unambiguously identified and its column density inferred.
- Dzhonson, E.B. Jochnowitz and J.P. Maier
“Electronic gas-phase spectra of larger polyacetylene cations”
J.Phys.Chem. A, 111, 1887, 2007.
Following the construction of a radiofrequency trap to study organic cations under interstellar conditions, the measurement of the electronic absorption spectra of polyacetylene cations, as large as HC16H+, at 20 K.
- Chakrabarty, M. Holz, A. Banerjee, D. Gerlich and J.P. Maier
“A novel method to measure electronic spectra of cold molecular ions”
J.Phys.Chem.Lett., 4, 4051, 2013.
Demonstration of a new universal method to measure the absorption spectra on merely a few thousand of mass-selected ions at 6 K.
- W.Campbell, M.Holz, D.Gerlich and J.P.Maier
“Laboratory confirmation of C60+ as carrier of two diffuse interstellar bands”
Nature, 523, 323, 2015. See also C60+ page
The highlight of my scientific endeavours. Twenty years after our observation of the absorption spectrum of C60+ in a neon matrix, development of a technique to produce and trap ions under interstellar temperatures, the measurement of its electronic spectrum in the gas phase at 6 K was successful. This provides unambiguous proof that C60+ is present in the diffuse interstellar clouds and led to the first identification of two diffuse interstellar bands (and subsequently of two further ones).