The formation of charge-transfer complexation between dibenzo-15-crown-5 (DB15C5) and benzo-12-crown-4 (B12C4) (Donor) and iodine is investigated spectrophotometrically in three chlorinated solvents,chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solution at 25°C. The change in polarityof the solvent also doesn’t affect the stoichiometry of the complexes. Values of formation cons...

We have explored intestinal function in the euryhaline killifish Fundulus heteroclitus after transfer from brackish water (10% seawater) to fresh water. Plasma Na+ and Cl- concentrations fell at 12 h post-transfer, but recovered by 7 days. Drinking rate decreased substantially at 12 h (32% of control value) and remained suppressed after 3 and 7 days in fresh water (34 and 43%). By contrast, the...

The water quality of the Karaj River was studied through collecting 2137 experimental data set gained by 20 sampling stations. The data included different parameters such as T (temperature), pH, NTU (turbidity), hardness, TDS (total dissolved solids), EC (electrical conductivity) and basic anion, cation concentrations. In this study a multi-layer perceptron artificial neural network model was d...

A highly sensitive analytical method is required for the assessment of nanomolar perchlorate contamination in drinking water as an emerging environmental problem. We developed the novel approach based on a voltammetric ion-selective electrode to enable the electrochemical detection of "redox-inactive" perchlorate at a nanomolar level without its electrolysis. The perchlorate-selective electrode...

ion/water transfer

Electron-ion collisions are one of the main processes that drive the relaxation towards equilibrium. Most theoretical approaches of the connected energy transfer consider only independent binary collisions (see, e.g., Refs. [1-3]); collective excitations are neglected. Although decoupled electron-ion modes have only small effects [4], Dharmawardana & Perrot found strongly reduced energy transfe...

[formula: see text] The structure of "guaninediazonium ion" in its aggregate with cytosine has been explored with ab initio and density functional methods. The hydrogen-bonded aggregate between cytosine and guaninediazonium ion, 1, is a stable minimum, 3. While the isolated enol tautomer of guaninediazonium ion, 2, is significantly more stable than 1, the tautomeric aggregate 4 that results fro...

The stoichiometry of macromolecular interactions is fundamental to cellular signalling yet challenging to detect from living cells. Fluorescence resonance energy transfer (FRET) is a powerful phenomenon for characterizing close-range interactions whereby a donor fluorophore transfers energy to a closely juxtaposed acceptor. Recognizing that FRET measured from the acceptor's perspective reports ...

Ion/ion reactions have in recent years seen widespread use in ion activation methods such as electron transfer dissociation (ETD) tandem mass spectrometry (MS/MS) as well as in charge manipulation of highly charged peptides/proteins and their fragments by proton transfer reaction (PTR). These techniques have, in combination, enabled top-down proteomics on limited-resolution benchtop mass spectr...

Three new electrodes were prepared by incorporating two different charge-transfer complexes and amino crown ether into plasticized PVC membranes. The electrodes showed Nernstian response to triiodide ion over the activity range from 1.0 x 10(-5) to 1.0 x 10(-1) mol x L(-1) with detection limits at approximately 1.0 x 10(-6) mol x L(-1). The resulting electrodes have fast response times (20-30 s...