LD-JC. Laser desorption jet-cooling spectroscopy

Abstract

Laser desorption followed by jet-cooling allows wavelength-selective as well as mass-selective detection of organic molecules desorbed from a surface without fragmentation. The absolute detection sensitivity is demonstrated with the perylene molecule. A two-color REMPI spectrum (400 wavelength points) of perylene is recorded using only 30 picogram of material. Rotational cooling to 5-10 K is demonstrated with laser-desorbed anthracene; vibrational cooling below 15 K is demonstrated with laser-desorbed diphenylamine. The ability to take a 'snapshot' of molecules on a surface is illustrated with the spectrum of benzoic acid monomers. Other applications are discussed, i.e. PABA dimer spectroscopy and detection of C60.