Experimental and theoretical study of hydration of halide ions

Mass spectrometric and quantum chemical determination of proton water clustering equilibria

“…However, the lowest temperature in their experiments was À60°C where water vapor could begin to condense in the ion source. We observed such condensation at À45°C in our experimental study of chloride (Likholyot et al, 2005b) as did Hiraoka et al (1988). The ice vapor pressure is 0.130 mbar at À40°C, 0.039 mbar at À50°C and only 0.011 mbar at À60°C (Lide, 1996).…”

“…Building on reported studies for protonated water clusters as well as on our recent experimental investigation of halide hydration (Likholyot et al, 2005b), we have reexamined the clustering equilibria of the hydronium ion with water using our recently constructed HPMS facility (Likholyot et al, 2005a), which incorporates some important design improvements. We have also complimented our experimental studies by performing a series of high accuracy ab initio calculations employing the G3 (Curtiss et al, 1998), G3B3 (Baboul et al, 1999), CBS/QCI-APNO (Montgomery et al, 1994), CBS-QB3 (Montgomery et al, 1999) and CBS-Q (Ochterski et al, 1996) model chemistries as well as density functional theory calculations (DFT) at the B3LYP level of theory to obtain equilibrium structures and incremental binding energies for selected isomers of protonated water clusters of rank n 6 8.…”

An unexpected ion‐molecule adduct in negative‐ion collision‐induced decomposition ion‐trap mass spectra of halogenated benzoic acids

“…It seems that halide ion hydrates,16 and cationic water clusters containing iodine,17 are widespread in nature. The formation of water adducts with an iodide anion in mass spectrometers has been investigated by several researchers 13–15. Initially, a simple symmetric structure (C 2v symmetry) was proposed21 for [X(H 2 O)] − .…”

“…The formation of water and other adducts with ions such as halides anions under ESI and other ionization conditions is also accepted as a general phenomenon 12–15. Halide ion hydrates,16 and cationic water clusters containing iodine,17 have received considerable attention because they are deemed to be widespread in nature.…”

Competitive interactions between components in surfactant–cosurfactant–additive systems

“…In conclusion, transfer of a greater amount of hydrophobic chains from the aqueous phase to a micelle should give a negative enthalpy effect. Considering the enthalpy of micellization, the difference between heptanol and heptanoic acid lies mainly in the number of cosurfactant units incorporated into micelles (per mole of HTAB), but also in the degree of Br -binding (partial dehydration of the specifically adsorbed bromide ions is endothermic [31]). …”