a new proton transfer compound, formulated as (hamp-6-pic)(hpyzd) ∙h2o (1), has been synthesized from the reaction of pyrazine-2,3-dicarboxylic acid (h2pyzd)  and 2-amino-6-methyl pyridine (amp-6-pic), in 1:1 molar ratio. extensive o−h×××o, n−h×××n and o−h×××o hydrogen bonds involving (hamp-6-pic)+ cation, (hpyzd)- anion and co-crystal water molecule٫ static electronic٫ and π…π stacking interac...

The O–H bond breaking in H2O molecules on metal surfaces covered with pre-adsorbed oxygen atoms is an important topic in heterogeneous catalysis. The adsorption configurations of H2O and relevant dissociation species on clean and O-pre-adsorbed Fe(100) surfaces were investigated by density functional theory (DFT). The preferential sites for H2O, HO, O, and H were investigated on both surfaces. ...

The preferential escape of the lighter isotope of hydrogen controls the global (D/H)H2O abundance ratio and comparison of the present abundance ratio with escape models provides an estimate of the amount of water lost over time. Earlier measurements reported a global atmospheric enrichment (D/H) of five times the mean terrestrial ocean value (VSMOW). Because of HDO and H2O different vapor press...

Abundance mass spectra, obtained upon carefully electrospraying solutions of tert-butanol (TB) in water into a mass spectrometer, display a systematic series of peaks due to mixed H(TB)m(H2O)n clusters. Clusters with m + n = 21 have higher abundance (magic number peaks) than their neighbours when m r 9, while for m 4 9 they have lower abundance. This indicates that the mixed TB–H2O clusters ret...

Abundance mass spectra, obtained upon carefully electrospraying solutions of tert-butanol (TB) in water into a mass spectrometer, display a systematic series of peaks due to mixed H(+)(TB)m(H2O)n clusters. Clusters with m + n = 21 have higher abundance (magic number peaks) than their neighbours when m ≤ 9, while for m > 9 they have lower abundance. This indicates that the mixed TB-H2O clusters ...

Vibrational and electronic photodissociation spectra of mass-selected protonated benzaldehyde-(water)n clusters, [BZ-(H2O)n]H(+) with n ≤ 5, are analyzed by quantum chemical calculations to determine the protonation site in the ground electronic state (S0) and ππ(*) excited state (S1) as a function of microhydration. IR spectra of [BZ-(H2O)n]H(+) with n ≤ 2 are consistent with BZH(+)-(H2O)n typ...

The structural and energetic characteristics of O3–H2O complexes have been investigated by means of B3LYP, MP2, MP4(SDTQ), CCSD(T) and QCISD(T) methods in conjunction with the AUG-cc-pVDZ and AUG-cc-pVTZ basis sets. Six conformers were found for the O3–H2O complex. Two different intermolecular interactions were expected to participate in the formation of complexes, namely conventional O∙∙∙H hyd...

Abstract: The mixture of DMSO-water was studied with Car-Parrinello simulation techniques. A threefold coordination at the DMSO oxygen, methyl group hydrogen-oxygen atom contacts, Russel-structures and 1-DMSO-3-H2O clusters are observed. The H(DMSO)-O(H2O) and the H(DMSO)-H(H2O) radial distribution functions are almost identical. For different far water the angular distribution displays a diale...

The Red cell-Hb-CSF functions as a sensor adapting response to Hb heterotropic equilibriums. At the lungs O2 and Mg2+, each one increasing affinity for the other stabilize the relax (R) form [(O2)4Hb(Mg)2].(H2O)R. At tissue level, the inclusion of H+ and 2,3-DPG excludes O2 and Mg2+ to stabilize the tense (T) form 2,3-DPG-deoxyHb-(H2O)T. Both senses are integrated into a cycle T into R and R in...