Experimental and Theoretical Investigations of Infrared Multiple Photon Dissociation Spectra of Aspartic Acid Complexes with Zn and Cd.

Complexes of aspartic acid (Asp) cationized with Zn: Zn(Asp-H), Zn(Asp-H)(ACN) where ACN = acetonitrile, and Zn(Asp-H)(Asp); as well as with Cd, CdCl(Asp), were examined by infrared multiple photon dissociation (IRMPD) action spectroscopy using light generated from a free electron laser. A series of low-energy conformers for each complex was found using quantum chemical calculations to identify the structures formed experimentally. The main binding motif observed for the heavy-metal complex, CdCl(Asp)[N,CO,CO], is a charge-solvated, tridentate structure, where the metal center binds to the backbone amino group and carbonyl oxygens of the backbone and side-chain carboxylic acids.

Binding energies of hydrated cobalt(ii) by collision-induced dissociation and theoretical studies: evidence for a new critical size.

The experimental sequential bond energies for loss of water from Co(HO) complexes, x = 5-11, are determined by threshold collision-induced dissociation (TCID) using a guided ion beam tandem mass spectrometer with a thermal electrospray ionization source. Kinetic energy dependent TCID cross sections are analyzed to yield 0 K thresholds for sequential loss of neutral water molecules. The thresholds are converted from 0 to 298 K values to give hydration enthalpies and free energies.

Binding energies of hydrated cobalt hydroxide ion complexes: A guided ion beam and theoretical investigation.

The sequential bond energies of CoOH(HO) complexes, where x = 1-4, are measured by threshold collision-induced dissociation using a guided ion beam tandem mass spectrometer. The primary dissociation pathway for all reactants consists of loss of a single water molecule. This is followed by the sequential loss of additional water molecules at higher collision energies for the x = 2-4 complexes, whereas the x = 1 reactant loses the OH ligand competitively with the HO ligand.

Correction: Structural characterization of gas-phase cysteine and cysteine methyl ester complexes with zinc and cadmium dications by infrared multiple photon dissociation spectroscopy.

Correction for 'Structural characterization of gas-phase cysteine and cysteine methyl ester complexes with zinc and cadmium dications by infrared multiple photon dissociation spectroscopy' by Rebecca A. Coates et al., Phys.

Correction: Zn and Cd cationized serine complexes: infrared multiple photon dissociation spectroscopy and density functional theory investigations.

Correction for 'Zn and Cd cationized serine complexes: infrared multiple photon dissociation spectroscopy and density functional theory investigations' by Rebecca A. Coates et al., Phys.

Thermochemical Investigations of Hydrated Nickel Dication Complexes by Threshold Collision-Induced Dissociation and Theory.

The experimental bond energies of Ni(HO) complexes, where x = 4-11, are determined by threshold collision-induced dissociation using a guided ion beam tandem mass spectrometer with an electrospray ionization source. The electrospray ionization source produces a distribution of Ni(HO) complexes, where an in-source fragmentation technique is employed to access the x = 4-6 complexes and control the population of excited isomers. The kinetic energy-dependent cross sections are modeled to yield 0 K bond energies for sequential loss of neutral water molecules, which are converted to 298 K binding energies.

Structural characterization of gas-phase cysteine and cysteine methyl ester complexes with zinc and cadmium dications by infrared multiple photon dissociation spectroscopy.

Structural characterization of gas-phase ions of cysteine (Cys) and cysteine methyl ester (CysOMe) complexed to zinc and cadmium is investigated by infrared multiple photon dissociation (IRMPD) action spectroscopy using a free electron laser in combination with density functional theory calculations. IRMPD spectra are measured for [Zn(Cys-H)](+), [Cd(Cys-H)](+), [Zn(CysOMe-H)](+), [Cd(CysOMe-H)](+) and CdCl(+)(CysOMe) and are accompanied by quantum mechanical calculations of the predicted linear absorption spectra at the B3LYP/6-311+G(d,p) (Zn(2+) complexes) and B3LYP/def2TZVP levels (Cd(2+) complexes). On the basis of these experiments and calculations, the conformation that best reproduces the IRMPD spectra for the complexes of the deprotonated amino acids, [M(Cys-H)](+) and [M(CysOMe-H)](+), is a charge-solvated (CS) tridentate structure where the metal dication binds to the amine and carbonyl groups of the amino acid backbone and the deprotonated sulfur atom of the side chain, [N,CO,S(-)].