Can the Hexagonal Ice-like Model Render the Spectroscopic Fingerprints of Structured Water? Feedback from Quantum-Chemical Computations

Abstract

Abstract:The spectroscopic features of the multilayer honeycomb model of structured water are analyzed on theoretical grounds, by using high-level ab initio quantum-chemical methodologies, through model systems built by two fused hexagons of water molecules: the monomeric system [H 19 O 10 ], in different oxidation states (anionic and neutral species). The findings do not support anionic species as the origin of the spectroscopic fingerprints observed experimentally for structured water. In this context, hexameric anions can just be seen as a source of hydrated hydroxyl anions and cationic species. The results for the neutral dimer are, however, fully consistent with the experimental evidence related to both, absorption and fluorescence spectra. The neutral π-stacked dimer [H 38 O 20 ] can be assigned as the main responsible for the recorded absorption and fluorescence spectra with computed band maxima at 271 nm (4.58 eV) and 441 nm (2.81 eV), respectively. The important role of triplet excited states is finally discussed. The most intense vertical triplettriplet transition is predicted to be at 318 nm (3.90 eV).

Water perturbed by cellophane: comparison of its physicochemical properties with those of water perturbed with cotton wool or Nafion

“…For this reason, the region has been designated "Exclusion Zone" (EZ). This zone seems to consist of excimers composed of H 2 O, which are organized in networks of ice-like layers [9,10]. Our conjecture is supported by our data on water repetitively brought in contact with Nafion ® -an inert hydrophilic membrane [11][12][13][14][15][16].…”

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“…These computations indicate that the aggregates in structured waters are composed of excimers (Segarra-Martí et al, 2014). In particular, CASPT2 analyses of EZ water adjacent to Nafion membranes have show that these excimers form networks of multilayer honeycomb ice-like layers [see Fig.…”

Exclusion Zone Phenomena in Water—A Critical Review of Experimental Findings and Theories

“…In response to this, in 1971 Hasted noted problems with hexagonal water structures in general, noting that high energy cost of placing hydrogens between oxygens was enough to make such structures explode if they were ever created [ 49 ]. Much more recently Seggara-Martí et al performed quantum chemistry calculations showing such a structure to be unstable [ 50 ]. Further quantum chemistry calculations were performed on two stacked hexagonal layers (each layer contained two hexagons and one negative change (H O ).…”

“…Further quantum chemistry calculations were performed on two stacked hexagonal layers (each layer contained two hexagons and one negative change (H O ). The negative charge did not distribute uniformly over the structure and optimization of the structure resulted in a “bulk-type water aggregate”, showing it to be unstable [ 50 ].…”