Interaction between p-toluenesulfonic acid (pTSA) and water is studied at -20 °C in a CCl matrix. In CCl water exists as monomers with restricted rotational motion about its symmetry axis. Additionally, CCl is transparent in the hydrogen-bonded region; CCl thus constitutes an excellent ambient thermal energy matrix isolation medium for diagnosing interactions with water.
View Article and Find Full Text PDFJ Phys Chem A
September 2014
Periodic static ab initio studies are conducted of hexagonal bilayer ice (HBL) and basal layers of ice-1h adsorbed on graphene using the model BLYP-D in CRYSTAL09. Eight high-symmetry periodic forms of HBL are optimized, of which four have lower energy; their electronic binding energy to graphene is ∼1.6 kcal/mol per abutting H2O.
View Article and Find Full Text PDFThe properties of the hydroperoxide anion, HOO(-), in water play a key role in many biological systems and industrial processes. However the dynamics of HOO(-) and its solvation shell are largely unknown. We have undertaken an ab initio molecular dynamics study of aqueous HOO(-) at ambient temperature in liquid water.
View Article and Find Full Text PDFHydroperoxide anion (HOO(-)), the conjugate base of hydrogen peroxide (HOOH), has been relatively little studied despite the importance of HOOH in commercial processes, atmospheric science, and biology. The anion has been shown to exist as a stable species in alkaline water. This project explored the structure of gas phase (HOO(-))(H(2)O)(n) clusters and identified the lowest energy configurations for n ≤ 8 at the B3LYP/6-311++G** level of theory and for n ≤ 6 at the MP2/aug-cc-pVTZ level of theory.
View Article and Find Full Text PDFFor (H(2)O)(20)X water clusters consisting of X enclosed by the 5(12) dodecahedral cage, X = empty, H(2)O, NH(3), and H(3)O(+), databases are made consisting of 55-82 isomers optimized via B3LYP/6-311++G(**). Correlations are explored between ground state electronic energy (Ee) or electronic energy plus zero point energy (Ee+ZPE) and the clusters' topology, defined as the set of directed H-bonds. Linear regression is done to identify topological features that correlate with cluster energy.
View Article and Find Full Text PDFObjectives: To analyze the solutes leaching from glass containers into aqueous solutions, and to show that these solutes have enzyme activity stabilizing effects in very dilute solutions.
Methods: Enzyme assays with acetylcholine esterase were used to analyze serially succussed and diluted (SSD) solutions prepared in glass and plastic containers. Aqueous SSD preparations starting with various solutes, or water alone, were prepared under several conditions, and tested for their solute content and their ability to affect enzyme stability in dilute solution.
Several hypothesized explanations for homeopathy posit that remedies contain a concentration of discrete information-carrying units, such as water clusters, nano-bubbles, or silicates. For any such explanation to be sustainable, dilution must reduce and succussion must restore the concentration of these units. Succussion can be modeled by a logistic equation, which leads to mathematical relationships involving the maximum concentration, the average growth of information-carrying units rate per succussion stroke, the number of succussion strokes, and the dilution factor (x, c, or LM).
View Article and Find Full Text PDFThe 'silica hypothesis' is one of several frameworks that have been put forward to explain how homeopathic remedies, which often are diluted beyond the point where any of the original substance remains, might still be clinically effective. We describe here what the silica hypothesis says. From a physical chemistry viewpoint, we explore three challenges that the hypothesis would have to meet in order to explain homeopathy: thermodynamic stability of a large number of distinct structures, pattern initiation at low potencies, and pattern maintenance or gradual evolution at higher potencies.
View Article and Find Full Text PDFPolyhedral water clusters (PWCs) are cage-like (H2O)n clusters where every O participates in exactly three H bonds. For a database of 83 PWCs, 8 < or = n < or = 20, geometry was optimized and zero point energy (ZPE) was calculated at the B3LYP/6-311++G** level. ZPE correlates negatively with electronic energy (E0): each increase of 1 kcal/mol in E0 corresponds to a decrease of about 0.
View Article and Find Full Text PDFJ Phys Chem A
April 2006
Infrared frequencies calculations were carried out for 20 (H2O)20 water clusters obeying the 5(12) dodecahedral geometry, optimized at the B3LYP/6-311++G** level. Their combined spectra contained 800 O-H stretch modes, ranging from 2181 to 3867 cm(-1) (unscaled), which were treated and studied as a database. Of these, 752 modes (94%) could be assigned to a single dominant O-H stretch.
View Article and Find Full Text PDFJ Chem Phys
December 2005
In order to explore the effect of H-to-D substitution on the zero-point energy (ZPE) of water clusters, Hessians were computed for a database of 53 optimized (H2O)n clusters, 5 < or = n < or = 21, at the B3LYP6-311 + + G** level. The 53 clusters contained 1524 protons, which were sorted into 18 categories according to the type of their donor O and (if not free) acceptor O. Letting deltaZPE[H]* denote the change in ZPE when the proton H* is replaced by D, mean values for deltaZPE[H*] for the H-bonded categories ranged from -2172 cal mol(-1) for H* in a DDAA-DDAA bond to -2118 for H* in a DAA-DDA bond.
View Article and Find Full Text PDFBMC Complement Altern Med
November 2004
Background: The efficacy of homeopathy is controversial. Homeopathic remedies are made via iterated shaking and dilution, in ethanol or in water, from a starting substance. Remedies of potency 12 C or higher are ultra-dilute (UD), i.
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