The dissociative photodetachment of O2 (H2O)n51 – 6 was studied at 388 and 258 nm using photoelectron–multiple-photofragment coincidence spectroscopy. Photoelectron spectra for the series indicate a significant change in the energetics of sequential solvation beyond the fourth water of hydration. Photoelectron–photofragment kinetic energy correlation spectra were also obtained for O2 (H2O)1 – 2...

We present the results of 22 GHz H2O maser observations of a sample of 85 post-Asymptotic Giant Branch (post-AGB) candidate stars, selected on the basis of their OH 1612 MHz maser and far-infrared properties. All sources were observed with the Tidbinbilla 70-m radio telescope and 21 detections were made. 86 GHz SiO Mopra observations of a subset of the sample are also presented. Of the 21 H2O d...

In this paper, the performance of the operational Level 2 MIPAS processor for offline data (versions 4.61 and 4.62) in the presence of cloud is examined. Using simulations of typical cloud scenarios, based on MIPAS cloud statistics for the tropics, the impact of varying cloud influence at 12 km and the tangent altitude above (i.e. 15 km) is investigated. It is found that with increased cloud pr...

To understand the initial hydration processes of MgCl2, we measured photoelectron spectra of MgCl2(H2O)n- (n = 0-6) and conducted ab initio calculations on MgCl2(H2O)n- and their neutral counterparts up to n = 7. A dramatic drop in the vertical detachment energy (VDE) was observed upon addition of the first water molecule to bare MgCl2-. This large variation in VDE can be associated with the ch...

The thermodynamic stabilities and IR spectra of the three water clusters (H2O)20, (H2O)54,, and (H2O)100 are studied by quantum-chemical computations. After full optimization of the (H2O)20,54,100 structures using the hybrid density functional B3LYP together with the 6-31+G(d,p) basis set, the electronic energies, zero-point energies, internal energies, enthalpies, entropies, and Gibbs free ene...

Context. Vibrationally excited emission from the SiO and H2O molecules probes the innermost circumstellar envelopes of oxygen-rich red giant and supergiant stars. VY CMa is the most prolific known emission source in these molecules. Aims. Observations were made to search for rotational lines in the lowest vibrationally excited state of H2O. Methods. The APEX telescope was used for observations ...

A novel Schiff base, ethyl 4-[(E)-(2-hydroxy-4-methoxyphenyl)methylene-amino]benzoate (HL), was prepared and structurally characterized on the basis of elemental analyses, (1)H NMR, (13)C NMR, UV-Vis and IR spectral data. Six new copper(II) complexes, [Cu(L)(NO3)(H2O)2] (1), [Cu(L)2] (2), [Cu(L)(OAc)] (3), [Cu2 (L)2Cl2(H2O)4] (4), [Cu(L)(ClO4)(H2O)] (5) and [Cu2(L2S)(ClO4)(H2O)]ClO4·H2O (6) hav...

This paper describes CHEM2D-H2O, a new parameterization of H2O photochemical production and loss based on the CHEM2D photochemical-transport model of the middle atmosphere. This parameterization accounts for the altitude, latitude, and seasonal variations in the photochemical sources and sinks of water vapor over the pressure region from 100–0.001 hPa (∼16–90 km altitude). A series of free-runn...

Three new supramolecular metal-coordination architectures [M(H2O)4(ampyz)2][M(H2O)6](SO4)2(H2O)2 (M = Co (1), Fe (2), and mixed Co/Fe (3); ampyz = 2-aminopyrazine) and a Cd(II) coordination polymer [Cd(ampyz)(H2O)2(SO4)]n(H2O)n (4) were synthesized by layered diffusion and structurally characterized. Compounds 1-3 are isomorphous. Monomeric complex units [M(H2O)4(ampyz)2]2+ are assembled by int...

Aerosol nucleation events have been observed at a variety of locations worldwide, and may have significant climatic and health implications. Binary homogeneous nucleation (BHN) of H2SO4 and H2O is the foundation of recently proposed nucleation mechanisms involving additional species such as ammonia, ions, and organic compounds, and it may dominate atmospheric nucleation under certain conditions...