Fritz-Haber-Institut der Max-Planck-Gesellschaft

Department of Molecular Physics

Infrared excitation of gas-phase molecules and clusters

Biomolecules in the gas phase Molecules of biological relevance are studied in the gas phase. By measuring their IR and far-IR spectra, information on the structure and on the intramolecular interactions is obtained. By exciting with modulated IR Pulses, active control of the confirmation will be possible. Such information can eventually be used to get a better picture on problems such as protein folding. Mass-selected ions in liquid helium droplets Liquid helium droplets are ultracold and superfluid and thus provide a unique environment for molecular species. In most experiments, however, droplets can only be doped with molecules that can be thermally evaporated, thus excluding interesting species such as larger biomolecules. We developed a machine that allows for the investigation mass-selected cluster or biomolecular ions in liquid helium droplets. The droplets are generated by a pulsed valve, kept at cryogenic conditions. They then traverse an ion trap, filled with mass-selected ions. Upon impact of a droplet on an ion, the ion can be embedded into the droplet and because of the high kinetic energy of the droplet (a result of its high mass), the doped droplet can leave the trap and be further investigated. Group Members Gert von Helden, Staff Scientist Peter Kupser, PhD Student Frauke Bierau, PhD Student Stephan Warnke, Diploma Student Former Group Members Dr. Marcin Frankowski Undine Erlekam, PhD Student

News Helium droplets loaded and charged! Mass-selected protein ions can be stored in an ion trap to be picked up by liquid helium droplets. Detection is performed by direct current measurement. A mass analysis shows that the droplets are very large and contain more than 1010 atoms. Work on further characterization of the protein doped helium droplets is in progress!

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Recent Publications

K. Pagel, P. Kupser, F. Bierau, N. C. Polfer, J. D. Steill, J. Oomens, G. Meijer, B. Koksch and G. von Helden.
Gas-phase IR spectra of intact alpha-helical coiled coil protein complexes
Int. J. Mass Spectom. Ion Process. 283, 161-168 (2009).
http://dx.doi.org/10.1016/j.ijms.2009.02.026

G. von Helden, I. Compagnon, M. N. Blom, M. Frankowski, U. Erlekam, J. Oomens, B. Brauer, R. B. Gerber and G. Meijer.
Mid-IR spectra of different conformers of phenylalanine in the gas phase
Phys. Chem. Chem. Phys. 10, 1248-1256 (2008).
http://dx.doi.org/10.1039/b713274c

P. Kupser, J. D. Steill, J. Oomens, G. Meijer and G. von Helden.
IR spectroscopy of gas-phase C₆₀^-
Phys. Chem. Chem. Phys. 10, 6862-6866 (2008).
http://dx.doi.org/10.1039/b811862k

F. Filsinger, U. Erlekam, G. von Helden, J. Kupper and G. Meijer.
Selector for structural isomers of neutral molecules
Phys. Rev. Lett. 100, 133003 (2008).
http://dx.doi.org/10.1103/PhysRevLett.100.133003

A. Fielicke, C. Ratsch, G. von Helden and G. Meijer.
The far-infrared spectra of neutral and cationic niobium clusters: Nb₅^(0/+) to Nb₉^(0/+)
J. Chem. Phys. 127, 234306 (2007).
http://dx.doi.org/10.1063/1.2806176

U. Erlekam, M. Frankowski, G. von Helden and G. Meijer.
Cold collisions catalyse conformational conversion
Phys. Chem. Chem. Phys. 9, 3786-3789 (2007).
http://dx.doi.org/10.1039/b703571c

R. A. DiStasio, G. von Helden, R. P. Steele and M. Head-Gordon.
On the T-shaped structures of the benzene dimer
Chem. Phys. Lett. 437, 277-283 (2007).
http://dx.doi.org/10.1016/j.cplett.2007.02.034

M. N. Blom, I. Compagnon, N. C. Polfer, G. von Helden, G. Meijer, S. Suhai, B. Paizs and J. Oomens.
Stepwise solvation of an amino acid: The appearance of zwitterionic structures
J. Phys. Chem. A 111, 7309-7316 (2007).
http://dx.doi.org/10.1021/jp070211r

A. Abo-Riziq, B. O. Crews, I. Compagnon, J. Oomens, G. Meijer, G. Von Helden, M. Kabelac, P. Hobza and M. S. de Vries.
The Mid-IR spectra of 9-ethyl guanine, guanosine, and 2-Deoxyguanosine
J. Phys. Chem. A 111, 7529-7536 (2007).
http://dx.doi.org/10.1021/jp072183i

B. Redlich, H. Zacharias, G. Meijer and G. von Helden.
Resonant infrared laser-induced desorption of methane condensed on NaCl(100): Isotope mixture experiments
J. Chem. Phys. 124, 044704 (2006).
http://dx.doi.org/10.1063/1.2159487

B. Redlich, A. Kirilyuk, T. Hoger, G. von Helden, G. Meijer and H. Zacharias.
Velocity distribution of CO desorbing from NiO(100)/Ni(100) after picosecond UV laser irradiation
Chem. Phys. Lett. 420, 110-114 (2006)
http://dx.doi.org/10.1016/j.cplett.2005.12.057

N. C. Polfer, J. Oomens, D. T. Moore, G. von Helden, G. Meijer and R. C. Dunbar.
Infrared spectroscopy of phenylalanine Ag(I) and Zn(II) complexes in the gas phase
J. Am. Chem. Soc. 128, 517-525 (2006).
http://dx.doi.org/10.1021/ja0549291

J. Oomens, B. G. Sartakov, G. Meijer and G. Von Helden.
Gas-phase infrared multiple photon dissociation spectroscopy of mass-selected molecular ions
Int. J. Mass Spectom. Ion Process. 254, 1-19 (2006).
http://dx.doi.org/10.1016/j.ijms.2006.05.009

J. Oomens, G. Meijer and G. von Helden.
An infrared spectroscopic study of protonated and cationic indazole
Int. J. Mass Spectom. Ion Process. 249, 199-205 (2006).
http://dx.doi.org/10.1016/j.ijms.2005.12.034

A. Fielicke, G. von Helden, G. Meijer, D. B. Pedersen, B. Simard and D. M. Rayner.
Size and charge effects on the binding of CO to late transition metal clusters
J. Chem. Phys. 124, 194305 (2006).
http://dx.doi.org/10.1063/1.2196887

U. Erlekam, M. Frankowski, G. Meijer and G. von Helden.
An experimental value for the B_1u C-H stretch mode in benzene
J. Chem. Phys. 124, 171101 (2006).
http://dx.doi.org/10.1063/1.2198828

I. Compagnon, J. Oomens, G. Meijer and G. von Helden.
Mid-infrared spectroscopy of protected peptides in the gas phase: A probe of the backbone conformation
J. Am. Chem. Soc. 128, 3592-3597 (2006).
http://dx.doi.org/10.1021/ja055378h

A. Bekkerman, E. Kolodney, G. von Helden, B. Sartakov, D. van Heijnsbergen and G. Meijer.
Infrared multiphoton ionization of superhot C₆₀: Experiment and model calculations
J. Chem. Phys. 124, 184312 (2006).
http://dx.doi.org/10.1063/1.2193520

C. Ratsch, A. Fielicke, A. Kirilyuk, J. Behler, G. von Helden, G. Meijer and M. Scheffler.
Structure determination of small vanadium clusters by density-functional theory in comparison with experimental far-infrared spectra
J. Chem. Phys. 122, 124302 (2005).
http://dx.doi.org/10.1063/1.1862621

N. C. Polfer, B. Paizs, L. C. Snoek, I. Compagnon, S. Suhai, G. Meijer, G. von Helden and J. Oomens.
Infrared fingerprint spectroscopy and theoretical studies of potassium ion tagged amino acids and peptides in the gas phase
J. Am. Chem. Soc. 127, 8571-8579 (2005).
http://dx.doi.org/10.1021/ja050858u

A. Fielicke, G. von Helden, G. Meijer, B. Simard and D. M. Rayner.
Gold cluster carbonyls: Vibrational spectroscopy of the anions and the effects of cluster size, charge, and coverage on the CO stretching frequency
J. Phys. Chem. B 109, 23935-23940 (2005).
http://dx.doi.org/10.1021/jp055856a

A. Fielicke, G. von Helden, G. Meijer, B. Simard and D. M. Rayner.
Direct observation of size dependent activation of NO on gold clusters
Phys. Chem. Chem. Phys. 7, 3906-3909 (2005).
http://dx.doi.org/10.1039/b511710k

A. Fielicke, G. von Helden, G. Meijer, D. B. Pedersen, B. Simard and D. M. Rayner.
Gold cluster carbonyls: Saturated adsorption of CO on gold cluster cations, vibrational spectroscopy, and implications for their structures
J. Am. Chem. Soc. 127, 8416-8423 (2005).
http://dx.doi.org/10.1021/ja0509230

A. Fielicke, C. Ratsch, G. von Helden and G. Meijer.
Isomer selective infrared spectroscopy of neutral metal clusters
J. Chem. Phys. 122, 091105 (2005).
http://dx.doi.org/10.1063/1.1872834

W. Chin, M. Mons, J. P. Dognon, R. Mirasol, G. Chass, I. Dimicoli, F. Piuzzi, P. Butz, B. Tardivel, I. Compagnon, G. von Helden and G. Meijer.
The gas-phase dipeptide analogue acetyl-phenylalanyl-amide: A model for the study of side chain/backbone interactions in proteins
J. Phys. Chem. A 109, 5281-5288 (2005).
http://dx.doi.org/10.1021/jp048037j

J. Antony, G. von Helden, G. Meijer and B. Schmidt.
Anharmonic midinfrared vibrational spectra of benzoic acid monomer and dimer
J. Chem. Phys. 123, 014305 (2005).
http://dx.doi.org/10.1063/1.1947191

J. Oomens, N. Polfer, D.T. Moore, L. van der Meer, A.G. Marshall, J.R. Eyler, G. Meijer, G. von Helden.
Charge-state resolved mid-infrared spectroscopy of a gas-phase protein
Phys. Chem. Chem. Phys.7, 1345-1348 (2005).
http://dx.doi.org/10.1039/b502322j

I. Compagnon, J. Oomens, J. Bakker, G. Meijer and G. von Helden.
Vibrational spectroscopy of a non-aromatic amino acid-based model peptide: identification of the gamma-turn motif of the peptide backbone
Phys. Chem. Chem. Phys. 7, 13-15 (2005).
http://dx.doi.org/10.1039/b417204c

W. Chin, J. P. Dognon, C. Canuel, F. Piuzzi, I. Dimicoli, M. Mons, I. Compagnon, G. von Helden and G. Meijer.
Secondary structures of short peptide chains in the gas phase: Double resonance spectroscopy of protected dipeptides
J. Chem. Phys. 122, 054317 (2005).
http://dx.doi.org/10.1063/1.1839862

Bakker, J.M., Ch.Plützer, I. Hünig, Th. Häber, I. Compagnon, G. von Helden, G. Meijer and K. Kleinermanns
Folding structures of isolated peptides as revealed by gas-phase mid-infrared spectroscopy'
ChemPhysChem 6, 120-128 (2005).
http://dx.doi.org/10.1002/cphc.200400345

W. Chin, I. Compagnon, J. P. Dognon, C. Canuel, F. Piuzzi, I. Dimicoli, G. von Helden, G. Meijer and M. Mons.
Spectroscopic evidence for gas-phase formation of successive beta-turns in a three-residue peptide chain
J. Am. Chem. Soc. 127, 1388-1389 (2005).
http://dx.doi.org/10.1021/ja042860b

J. J. Valle, J. R. Eyler, J. Oomens, D. T. Moore, A. F. G. van der Meer, G. von Helden, G. Meijer, C. L. Hendrickson, A. G. Marshall and G. T. Blakney.
Free electron laser-Fourier transform ion cyclotron resonance mass spectrometry facility for obtaining infrared multiphoton dissociation spectra of gaseous ions
Rev. Sci. Instrum. 76, 023103 (2005).
http://dx.doi.org/10.1063/1.1841953

D. T. Moore, J. Oomens, J.R. Eyler, G. Meijer, G. von Helden, D. P. Ridge
Gas-Phase IR Spectroscopy of Anionic Iron Carbonyl Clusters
J. Am. Chem. Soc. 126, 14726-14727 (2004).

J. Oomens, G. von Helden and G. Meijer
Infrared Photodissociation Spectroscopy of the Benzoic Acid Radical Cation in a Quadrupole Trap
Journal of Physical Chemistry A 108 (40), 8273-8278 (2004).

P. Çarçabal, R. T. Kroemer, L. C. Snoek, J. P. Simons, J. M. Bakker, I. Compagnon, G. Meijer, and G. von Helden
Hydrated complexes of tryptophan: ion dip infrared spectroscopy in the 'molecular fingerprint' region, 100-2000cm^-1
Physical Chemistry Chemical Physics 6(19), 4546-4552 (2004).

A. Fielicke, G. von Helden, G. Meijer, D.B. Pedersen, B. Simard and D.M. Rayner
Size and charge effects on the binding of CO to small isolated rhodium clusters
Journal of Physical Chemistry B 108(38), 14591-14598 (2004)

T. D. Jaeger, D. van Heijnsbergenm , J. Klippenstein, G. von Helden, G. Meijer and M.A. Duncan
Vibrational Spectroscopy and Density Functional Theory of Transition-Metal Ion-Benzene and Dibenzene Complexes in the Gas Phase
Journal of the American Chemical Society 126(35), 10981-10991 (2004).

T. D. Jaeger, A. Fielicke, G. von Helden, G. Meijer and M.A. Duncan
Infrared spectroscopy of water adsorption on vanadium cluster cations (Vx+; x=3-18)
Chemical Physics Letters 392, 409-414 (2004).

K. Demyk, D. van Heijnsbergen, G. von Helden and G. Meijer
Experimental study of gas phase titanium and aluminium oxide clusters
Astronomy and Astrophysics 420, 547-552 (2004).

A. Fielicke, A. Kirilyuk, C. Ratsch, J. Behler, M. Scheffler, G. von Helden and G. Meijer
Structure determination of isolated metal clusters via far-infrared spectroscopy
Physical Review Letters, 93(2), 023401-1-4 (2004)

J. M. Bakker, I. Compagnon, G. Meijer, G. von Helden, M. Kabelac, P. Hobza and M. S. de Vries
The mid-IR absorption spectrum of gas-phase clusters of the nucleobases guanine and cytosine
Physical Chemistry Chemical Physics 6(10), 2810-2815 (2004).

D. T. Moore, J. Oomens, L. van der Meer, G. von Helden, G. Meijer, J. Valle, A.G. Marshall and J.R. Eyler
Probing the vibrations of shared, OH+O-bound protons in the gas phase
ChemPhysChem 5,740-743 (2004).

R. T. Jockusch, R.T. Kroemer, F.O. Talbot, L.C. Snoek, P. Carcabal, J.P. Simons, M. Havenith, J.M. Bakker, I. Compagnon, G. Meijer and G. von Helden
Probing the glycosidic linkage: UV and IR ion-dip spectroscopy of a lactoside
Journal of the American Chemical Society 126(18), 5709-5714 (2004).

J. Oomens, D.T. Moore, G. Meijer and G. von Helden
Infrared multiple photon dynamics and spectroscopy of cationic PABA and its dehydroxylated fragment ion
Physical Chemistry Chemical Physics 6(4), 710-718 (2004).

J. Oomens, D.T. Moore, G. von Helden, G. Meijer and R.C. Dunbar
The site of Cr+ attachment to gas-phase aniline from infrared spectroscopy
Journal of the American Chemical Society 126(3), 724-725 (2004).