Arn+H3 ions are produced in a laser vaporization source, and their stability against black-body radiation is tested in an FT-ICR mass spectrometer. Using a magnesium target and hydrogen doped argon as carrier gas, Arn+H3 are formed with n = 1-3 in large quantities and traces of n = 4. Arn+H, n = 1-3 are also present. Both Ar3+H3 and Ar2+H3 are heated by room temperature black-body radiation and decay on a timescale of seconds. The observed rate constants

A new variant of nanocalorimetry is proposed for the thermochemical analysis of ion–molecule reactions of hydrated ions in the gas phase. The average number of water molecules evaporating during the reaction is extracted by quantitative modeling of the average number of water molecules in the reactant and product cluster distribution as a function of time, taking into account black-body radiation induced dissociation. The method is tested on reactions

The structure of the sodiated peptide GGGGGGGG-Na+ or G8-Na+ was investigated by infrared multiple photon dissociation (IRMPD) spectroscopy and a combination of theoretical methods. IRMPD was carried out in both the fingerprint and N–H/O–H stretching regions.Modeling used the polarizable force field AMOEBA in conjunction with the replica-exchange molecular dynamics (REMD) method, allowing an efficient exploration of the potential energy surface.

Spectral assignment of the IRMPD bands and identification of the vibrational signatures of deprotonated phosphorylated amino acids are attained. The H2PO4- anion is used as a simple model of a free deprotonated phosphate group to identify the IR signatures of phosphorylation. The fragmentation efficiency is lower for [pSer-H]- than for [pThr-H]- and [pTyr-H]-. Gas-phase infrared spectra of deprotonated phosphorylated amino acids ([pAA-H]-) - phosphoserine

A novel design for a temperature-controlled ICR cell is described for use in black-body infrared radiative dissociation (BIRD) studies of weakly bound systems like water clusters. Due to several improved design features, it provides a very uniform black-body radiation environment, and at the same time maintains efficient pumping for a low collision rate on the order of 10^-2 s^-1. At the lowest temperatures reached, nominally 89 K cell plate temperature,

Structural characterization of protonated phosphorylated serine, threonine, and tyrosine was performed using mid-infrared multiple photon dissociation (IRMPD) spectroscopy and density functional theory (DFT) calculations. The ions were generated and analyzed by an external electrospray source coupled to a Paul ion-trap type mass spectrometer. Their fragmentation was induced by the resonant absorption of multiple photons from a tunable free electron

The structures of the sodium complexes of oligoglycines (GG-Na+, GGG-Na+) and oligoalanines (AA-Na+, AAA-Na+) have been studied in the gas phase. Two different experimental set-ups have been used to generate, trap and analyse the ions. In the first, the complexes were generated by MALDI and analyzed in the cell of a home built FT-ICR mass spectrometer. In the second an external electrospray source was coupled to a Paul type ion trap. Following their

The reactions of water cluster anions (H2O)n-, n = 30-70, with hydrogen chloride have been studied by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. The first HCl taken up by the clusters is presumably ionically dissolved. The solvated electron recombines with the proton, which is thereby reduced to atomic hydrogen and evaporates from the cluster. This process is accompanied by blackbody radiation and collision induced loss

Current works in cluster chemistry focus on extrapolating information on bulk properties from gas-phase cluster experiments. Concerted proton transfer by the Grotthuss mechanism is a key step in aqueous reactions, especially in acid–base chemistry. This process has recently been studied in bulk solution by time-resolved spectroscopy as well as ab initio molecular-dynamics simulations. Understanding the conditions for the occurrence of proton transfer

The reactivity of cationic rhodium clusters, Rh(n)+, n = 1–23, with ethane is studied by Fourier transform ion cyclotron resonance mass spectrometry. Single and double dehydrogenation with elimination of molecular hydrogen are the reactions observed. The reaction efficiency and branching ratio are strongly dependent on cluster size. The behavior is attributed to geometric effects, suggesting that dehydrogenation of ethane on cationic rhodium clusters