Hydration of the Calcium Dication: Direct Evidence for Second Shell Formation from Infrared Spectroscopy

Bush, Matthew F.; Saykally, Richard J.; Williams, Evan R.

doi:10.1002/cphc.200700404

Cited by 89 publications

(189 citation statements)

References 77 publications

Supporting

Mentioning

160

Contrasting

Order By: Relevance

“…With increasing number of water molecules, these do not anymore only act as ligands directly attached to the metal cation, but also form extended networks among each other via hydrogen bonding. Due to the resulting structural richness and fluxionality of larger M(H 2 O) n z+ ions, the combination of experiment and theory is particularly important in this area [15,16].…”

Section: Hydrated Coinage-metal Ionsmentioning

confidence: 99%

Theory meets experiment: Gas-phase chemistry of coinage metals

Roithová

Schröder

2009

Coordination Chemistry Reviews

View full text Add to dashboard Cite

Section: Hydrated Coinage-metal Ionsmentioning

confidence: 99%

Theory meets experiment: Gas-phase chemistry of coinage metals

Roithová

Schröder

2009

Coordination Chemistry Reviews

View full text Add to dashboard Cite

“…The ability to form gaseous hydrated clusters of many di-(1) and trivalent (2) ions has greatly expanded the capabilities of mass spectrometry to investigate important ion solvation problems. Structural information of hydrated ions has been obtained from a variety of thermochemical methods (3)(4)(5) and spectroscopy (6)(7)(8)(9). From these studies, information about how water molecules organize around ions and how water can affect the structures of ions themselves can be obtained (8,9).…”

Section: ؉mentioning

confidence: 99%

“…For Co(NH 3 ) 6 (H 2 O) n 3ϩ , the average number of lost water molecules decreases for n Ն 40. This can be attributed predom- inantly to improved ion stabilization with increasing solvation.…”

Section: Effects Of Cluster Size and Metal Ion Identity On Ec Reactivmentioning

confidence: 99%

“…In addition to the effect of ion solvation, surface energy effects, in which the binding energy of a water molecule to a cluster increases slightly with increasing size, and a degrees of freedom effect, in which larger ions dissociate more slowly with increasing size for a fixed amount of deposited energy, may also contribute. Because the degrees of freedom effect would lead to a decrease in the average number of water molecules lost and because surface energy effects should be similar for the Co(NH 3 ) 6 (H 2 O) n 3ϩ data at these cluster sizes, the near constant number of water molecules lost for Ca(H 2 O) n 2ϩ with n between 47 and 62 is surprising and indicates that an additional factor, such as a structural change, must contribute to the observed water loss in this size regime. (Fig.…”

Section: Effects Of Cluster Size and Metal Ion Identity On Ec Reactivmentioning

confidence: 99%

See 1 more Smart Citation

Nanocalorimetry in mass spectrometry: A route to understanding ion and electron solvation

Donald

Leib

O’Brien

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

A gaseous nanocalorimetry approach is used to investigate effects of hydration and ion identity on the energy resulting from ionelectron recombination. Capture of a thermally generated electron by a hydrated multivalent ion results in either loss of a H atom accompanied by water loss or exclusively loss of water. The energy resulting from electron capture by the precursor is obtained from the extent of water loss. Results for large-size-selected clusters of Co(NH 3)6(H2O)n 3؉ and Cu(H2O) n 2؉ indicate that the ion in the cluster is reduced on electron capture. The trend in the data for Co(NH 3)6(H2O)n 3؉ over the largest sizes (n > 50) can be fit to that predicted by the Born solvation model. This agreement indicates that the decrease in water loss for these larger clusters is predominantly due to ion solvation that can be accounted for by using a model with bulk properties. In contrast, results for Ca(H 2O)n 2؉indicate that an ion-electron pair is formed when clusters with more than Ϸ20 water molecules are reduced. For clusters with n ‫؍‬ Ϸ20 -47, these results suggest that the electron is located near the surface, but a structural transition to a more highly solvated electron is indicated for n ‫؍‬ 47-62 by the constant recombination energy. These results suggest that an estimate of the adiabatic electron affinity of water could be obtained from measurements of even larger clusters in which an electron is fully solvated.clusters ͉ ECD ͉ recombination ͉ hydration I on-solvent interactions are fundamental to many important phenomena in chemistry and biology, including ion transport across cell walls, salt-bridge formation, surface tension, and protein stability, yet many aspects of such interactions are still not well understood. Mass spectrometry is an important tool for probing ion-solvent interactions and has been widely used to obtain valuable thermochemical information. The ability to form gaseous hydrated clusters of many di-(1) and trivalent (2) ions has greatly expanded the capabilities of mass spectrometry to investigate important ion solvation problems. Structural information of hydrated ions has been obtained from a variety of thermochemical methods (3-5) and spectroscopy (6-9). From these studies, information about how water molecules organize around ions and how water can affect the structures of ions themselves can be obtained (8,9).Investigating the most fundamental aqueous ion, the hydrated electron, is challenging because of its powerful reducing nature (E 1/2 0 ϭ Ϫ2.87 V) (10) and high reactivity. Solvated electrons have been observed in many different solvents (11) and are important intermediates in radiation chemistry, electron transfer processes, and many biological processes, including those that can lead to irreversible cell damage. The structure of the hydrated electron has been investigated by several methods, including electron spin resonance (12) and Raman spectroscopy (13), but many details about the structure of the solvent cavity that traps the electron remain elusive.Information ab...

show abstract

“…In addition, for the heptahydrated metal ions, the seventh water molecule was shown to be in an outer solvation shell, bound much more weakly, by observing the rates of unimolecular dissociation reactions losing subsequent water molecules. Recently, the structures of hydrated Ca 2ϩ ions directly from an electrospray source have been studied by consequence spectroscopy [12] and thermochemically by collision-induced dissociation in a guided ion beam tandem mass spectrometer [13]. These…”

mentioning

confidence: 99%

Solvation of electrosprayed ions in the accumulation/collision hexapole of a hybrid Q-FTMS

Rajabi

Easterling

Fridgen

2009

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

In an effort to spectroscopically determine the structures of solvated ions composed of nucleic acid bases and amino acids, methods for their gas-phase synthesis have been studied. Ions were electrosprayed and solvated in the accumulation cell of a hybrid Q-FTICR filled with methanol or water vapor at ϳ10 Ϫ2 bar. There were subsequently transferred to the FTICR cell at 10 Ϫ10 mbar. Following their isolation in the FTICR, they can be investigated by studying their unimolecular blackbody infrared radiative dissociation (BIRD) or infrared multiple photon dissociation (IRMPD) spectroscopy. The IRMPD spectra for (Ade) 2 Li ϩ and (Ade) 2 Li(H 2 O) ϩ are reported and compared as well as BIRD rate constants for multiply solvated and metalated adenine ions. . The structural properties are typically deduced from fundamental studies of their thermochemistries, reactivities, and more recently, the vibrational spectroscopy of gaseous ions [2]. The ultimate purpose and challenge for studying the physical properties of sequentially solvated ions is to extrapolate to, or contrast these properties with, those in the solution phase especially for biologically interesting ions. Mass spectrometry has become a powerful technique for investigating biomolecules following the development of electrospray ionization (ESI) [3] and matrix-assisted laser desorption/ionization (MALDI) [4 -6]. Noncovalently bound biological complexes can be transferred from aqueous solutions to the gas phase by ESI for further study of the completely desolvated complex. In some instances a small amount of solvated ions have been reported from electrospray allowing the structure, reactivity and thermochemistry of the hydrated ions to be studied [7]. Lee et al.[8] studied extensively hydrated peptides from an electrospray source by operating the capillary at room-temperature, with no nebulizer or drying gas, and optimizing the potentials in the electrospray source. These ions were found to be cooled to between 130 and 150 K by evaporation of water without drying gas, effectively freezing the biomolecules. RodriguezCruz et al. [9] studied doubly protonated gramicidin S ions with up to 50 water molecules attached in a modified instrument with a home-built electrospray source equipped with a heated capillary inlet. They formed the ions under "gentle" electrospray conditions and later described two possible mechanisms for formation of hydrated ions by ESI [10], condensation of solvent onto ions due to expansion inside the ESI interface, and/or solvent evaporation of more extensively hydrated ions or electrospray droplets. The extent of hydration of gas-phase gramicidin S (M ϩ 2H) 2ϩ ions was observed to decrease with an increase in the temperature of the capillary.Rodriguez-Cruz and Williams [11] also studied solvent exchange reactions of hydrated divalent alkaline earth metals with benzene by ESI Fourier-Transform mass spectrometry (FTMS) at room temperature. Aqueous solutions of metal chloride salts were introduced to the mass spectrometer by nanoelectrospray. Me...

show abstract

Hydration of the Calcium Dication: Direct Evidence for Second Shell Formation from Infrared Spectroscopy

Cited by 89 publications

References 77 publications

Theory meets experiment: Gas-phase chemistry of coinage metals

Theory meets experiment: Gas-phase chemistry of coinage metals

Nanocalorimetry in mass spectrometry: A route to understanding ion and electron solvation

Solvation of electrosprayed ions in the accumulation/collision hexapole of a hybrid Q-FTMS

Contact Info

Product

Resources

About