Iodide Ions In Aqueous Solution Research Articles

Highly selective fluorescence sensor based on azido pyrazole-chalcone conjugates for rapid detection of iodide ion

Present study disclosed the synthesis of iodide (I−) ion fluorescence sensor based on azido pyrazole-chalcone derivatives for selective detection of iodide ion in pure form. The azido pyrazole-chalcone derivatives were obtained from condensation reaction of 5-azido-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde and various acetophenones under alkaline methanol. The developed fluorescence sensor compound 4A shown selective fluorospectrometric recognition of I− via fluorescence TURN-OFF mechanism, while the various competitive anions (N3−, BrO3−, OH−, SO3−, CN−, Br−, NO3−, CO3−2, HPO4−, CH3COO−, SCN− and NO2−) did not led to any noticeable interference. The iodide ion showed linear correlation with fluorescence intensity of developed fluorescence sensor over the concentration range 7.5 to 37.5 mM. The correlation coefficient value of the method is 0.9906 with 2.5 mM detection limit of iodide ion. Further, azido pyrazole-chalcone 4A as sensor showed high Stokes shift and selectivity towards iodide anion. The decay study of 4A showed decreased lifetime in the presence of iodide ion which indicates dynamic quenching mechanism. The synthesized compound 4A was also capable to detect iodide ion in catalyst like KI and TBAI. The outcomes of the method showed that synthesized fluorescence sensor (4A) was selective and sensitive detector of iodide ion in aqueous solution.

Schiff base complexes of Cu(II) and Ni(II) derived from N,N'-bis(salicylidene)-o-phenylenediamine as potential ionophores in the construction of PVC membrane iodide sensors

Two Schiff base compl exes of Cu(II) and Ni(II),designated as M1 and M2, respectively were synthesized from N,N'-bis(salicylidene)-o-phenylenediamine and characterized by IR and NMR spectroscopy. The results of conductometric and stability constant revealed that these complexes with several anions created the possibility of their use as potential ionophores in the development of iodide selective sensors. Poly(vinyl chloride)(PVC) membrane sensors of these complexes using several plasticizers (o-NPOE, CN, TBP, DOP and DBP) and cationic additive (CTAB) were fabricated as well as examined for the detection of iodide ions in aqueous solution. The performance characteristics of the various sensors of these ionophores exhibited that sensors having membrane composition as M1(4 mg):PVC(34 mg):TBP(62 mg):CTAB(7 mg) and M2(4 mg):PVC(34 mg):TBP(62 mg):CTAB(5 mg) showed best characteristics regarding Nernstian slope (59.4 and 59.2 mV decade−1 of [I-]), linear working range (6.3 ×10−8-3.2 ×10−2 mol L−1 and 7.9 ×10−8-1.0 ×10−2 mol L−1), detection limit (3.8 ×10−8 mol L−1 and 5.6 ×10−8 mol L−1) and response time of 7 and 9 s, respectively. These sensors performed well in the pH range of (4.0–9.0) and showed adequate shelf lives with 20% (v/v) non-aqueous tolerance. The proposed sensors served as indicator electrodes in the potentiometric titration of iodide ions against silver nitrate solution and in the determination of iodide ion concentration in mouthwash and river water samples.

Colorimetric detection of iodide ion by a nuclear fast red-based Hg2+ complex in aqueous media

The simple mixture of nuclear fast red (NFR) and Hg2+ containing poly(diallyldimethylammonium chloride) (PDADMAC) was found to be colorimetric detection for iodide ion in aqueous solution via the indicator displacement assay. NFR was complexed with Hg2+ in a 2:1 molar ratio (NFR2-Hg2+) and showed a bathochromic shift in the absorption peak. The addition of iodide ion to NFR2-Hg2+ displayed a hypsochromic shift with change back of color from reddish violet to pink by the restoration of NFR. The detection of iodide ion was not significantly affected by other anions. Therefore, NFR2-Hg2+ containing PDADMAC has been used as a simple colorimetric chemosensor for iodide ion in aqueous solution.

Naphthalene-glycine conjugate: An extremely selective colorimetric chemosensor for iodide ion in aqueous solution

A distinctive water soluble chemosensor based on naphthalene-glycine conjugate has been designed. The synthesized molecule is highly selective and sensitive towards detection of iodide ion in aqueous solution. The probe exhibits a color change from colorless to pale pink that can be detected by naked eye which is a simple and cost effective detection method. Further, addition of iodide ion led to the complete diminution of the fluorescence intensity of ligand 1. Under optimal conditions, its response was linearly proportional to the concentration of I− ion (range from 6.25 × 10−6 to 3.12 × 10−5 mol L−1) with a detection limit of 30 nM. Based on the 1H NMR titration, ESI–MS data and Job’s plot, the probable binding mode of this receptor with iodide ion has also been postulated and binding ratio of ligand to I− ion is found to be 2:1. This result is also supported by the theoretical calculation using DFT method. The molecular structure of 1 revealed the existence of different intermolecular CH/O and OH/N hydrogen bonds which led to the formation of a zig-zag linear 1D tape. Furthermore, the selectivity and sensitivity of the present probe towards iodide ion is also preserved on test kits made of cellulose bound filter paper and on supported solid silica.

A highly selective colorimetric chemosensor for detection of iodide ions in aqueous solution

A simple chemosensor can be used as a colorimetric sensor for the highly selective and sensitive detection of iodide anions in aqueous solution.

A laboratory characterisation of inorganic iodine emissions from the sea surface: dependence on oceanic variables and parameterisation for global modelling

Abstract. Reactive iodine compounds play a significant role in the atmospheric chemistry of the oceanic boundary layer by influencing the oxidising capacity through catalytically removing O3 and altering the HOx and NOx balance. The sea-to-air flux of iodine over the open ocean is therefore an important quantity in assessing these impacts on a global scale. This paper examines the effect of a number of relevant environmental parameters, including water temperature, salinity and organic compounds, on the magnitude of the HOI and I2 fluxes produced from the uptake of O3 and its reaction with iodide ions in aqueous solution. The results of these laboratory experiments and those reported previously (Carpenter et al., 2013), along with sea surface iodide concentrations measured or inferred from measurements of dissolved total iodine and iodate reported in the literature, were then used to produce parameterised expressions for the HOI and I2 fluxes as a function of wind speed, sea-surface temperature and O3. These expressions were used in the Tropospheric HAlogen chemistry MOdel (THAMO) to compare with MAX-DOAS measurements of iodine monoxide (IO) performed during the HaloCAST-P cruise in the eastern Pacific ocean (Mahajan et al., 2012). The modelled IO agrees reasonably with the field observations, although significant discrepancies are found during a period of low wind speeds (< 3 m s−1), when the model overpredicts IO by up to a factor of 3. The inorganic iodine flux contributions to IO are found to be comparable to, or even greater than, the contribution of organo-iodine compounds and therefore its inclusion in atmospheric models is important to improve predictions of the influence of halogen chemistry in the marine boundary layer.

Map for the Relaxation Dynamics of Hot Photoelectrons Injected into Liquid Water via Anion Threshold Photodetachment and above Threshold Solvent Ionization

The early time dynamics of electron photoejection and relaxation after one-photon UV photodetachment of iodide ions in aqueous solution is compared with that resulting from two-photon ionization of neat water. The effect of solvent composition on the ejection and relaxation is probed via experiments on iodide photodetachment in a water/ethylene glycol mixture. Representation of our pump−multiple wavelength probe experimental data sets as two-dimensional contour plots provides a convenient fingerprint of the electron dynamics. Global fitting of the data to a solvation model for spectral evolution indicates varying time scales for solvation for each of the ejection systems. In all cases, the spectral evolution is complete in the first 10 ps, however electrons ejected via the anion charge-transfer-to-solvent pathway relaxes by a factor of 2 slower. For iodide detachment in the water/glycol mixture, evidence is found for a precursor excess electron state in the infrared that decays on the order of 250 fs. No evidence for an electron precursor state is found for the ionization of water within the 400−1000 nm window studied, and the ground state is apparent within 200 fs. From these results, and from picosecond scale recombination dynamics presented elsewhere (Kloepfer et al. J. Chem. Phys. 2000, 113, 6288−6307), we conclude that the electron production mechanism is distinct for the anion detachment and solvent ionization pathways.

Dynamics of Fluorescence Quenching of Pyrene in Novel Micelles of the Zwitterionic Betaine SurfactantN-(3-Dodecyloxy-2-hydroxypropyl)-N,N-dimethylglycine

Time-resolved and steady-state fluorescence have been employed to study the fluorescence quenching of pyrene, solubilized in novel micelles of the zwitterionic surfactant,N-(3-dodecyloxy-2-hydroxy propyl)-N,N-dimethylglycine (DHDG), by iodide ions in aqueous solution. The fluorescence quenching rate constants (kq), micellar exit rate constants (k–), and micellar aggregation numbers (N) have been determined in each case. Generally the fluorescence quenching rates in micellar solutions with pH values above the isoelectric point (pH 5.1) (zwitterionic) of DHDG are lower than when pH is below 5.1 (cationic). Addition of NaCl results in a moderate variation of the micellar aggregation numbers and a subsequent change inkq. When cationic and zwitterionic DHDG micelles have the same micelle aggregation number,kqin the cationic DHDG micelles is higher, suggesting that both the aggregation number and the micellar surface potential related to the charge of head groups influencekq. The dynamics of iodide ion exit from DHDG micelles has also been studied. The exit rate constants of iodide ion from micelles,k–, is independent of micelle concentration (in the range studied), but is dependent on micellar aggregation number and is related to micellar interfacial potential. The steady-state and time-resolved fluorescence measurements agree very well, suggesting the importance of dynamic fluorescence quenching processes.

Kinetics Studies in a Washing Bottle

The kinetics of the decomposition of hydrogen peroxide using iodide ion in aqueous solution is studied in sealed completely-filled washing bottles. Oxygen gas produced by the decomposition of the hydrogen peroxide forces liquid out of a bottom feeding washing bottle. After an initiation period of a few minutes at room temperature, the rate at which the liquid is expelled from the spout of the of the washing bottle stabilizes. A comparison of the rates for different reaction concentrations results in a rate law that is approximately first-order with respect to both hydrogen peroxide and iodide concentrations. Because the need for a gas buret to measure oxygen volumes is not necessary, the experiment can be conveniently performed by a student seated in a wheelchair.

Kinetics and mechanism of substitution of [RuIII(Hedtra)(H2O)] (Hedtra = N-hydroxyethylethylenediaminetriacetate) with iodide ion in aqueous solution

The interaction of iodide ion with [RuIII(Hedtra)(H2O)] (Hedtra = N-hydroxyethylethylenediaminetriacetate) was investigated by spectrophotometry, electrochemical and stopped-flow techniques. The rate of formation of a red [RuIII(Hedtra)I]− complex was found to be first order both with respect to [RuIII(Hedtra)(H2O)] and [I−]. Rate and activation parameters are consistent with the proposed associative interchange mechanism. Experimental results are discussed with reference to the data available for other ligand substitutions of the [RuIII(Hedtra)(H2O)] complex.

Kinetic study of the reaction of meso-tetrakis ( p-trimethylammoniumphenyl)porphinatodiaquacobalt(III) with thiocyanate and iodide ions in aqueous solution

The reaction of meso-tetrakis( p-trimethylammoniumphenyl)porphinatodiaquacobalt(III) with NCS − and I − ions has been studied at 15, 25 and 35°C in 0.1 mol dm −3 [H +] (HNO 3) and μ = 1.0 mol dm −3 (NaNO 3). The values of the acidity constants, K a1 and K a2, for the diaqua complex at 25°C are 3.3(5) x 10 −7 and 2.0(2) x 10 −11 mol dm −3, respectively. The reactions are first order in ligand concentration up to 0.9 mol dm −3. The values of the second-order rate constants at 25°C are 89.0(5) and 76.0(4) dm 3 mol −1 s −1 for NCS − and I −, respectively. The values of Δ S ‡ for the different incoming ligands are positive or nearly positive, which is indicative of dissociative activation. The value of the activation volume [Δ V ‡ = 18.8(8) cm 3 mol −1] indeed points to a dissociative mechanism. The porphine ligand greatly labilizes the cobalt(III). There is about a 10 8-fold increase in the rate constant for substitution compared with that of [Co(NH 3) 5(H 2O)] 3+. It is proposed that the electron-rich porphine not only labilizes the M III ion (M = Co, Rh and Cr) but also promotes a more dissociative activation mode relative to that of the corresponding [M(NH 3) 5(H 2O)] 3+ complexes. The extent of labilization depends on the electron-donating ability of the porphine as well as the nature of the central metal ion. It is also shown that the overall charge of the complex, whether positive or negative (as determined by the formal charge of the porphine), plays a minor role in the mechanism of the substitution reaction.

Magnetic circular dichroism in the charge-transfer-to-solvent excited states of iodide ion in aqueous solution

Magnetic circular dichroism (MCD) spectra of iodide ions in solution are measured in the two resolved ultraviolet absorption bands that have been attributed to the charge-transfer-to-solvent (CTTS) excitation resulting in the iodine atom in 2P1/2 and 2P3/2 states. The relative absorption intensities and Faraday parameters of the twin bands in aqueous solution are theoretically reproduced with values of exchange interaction K = 500–600 cm-1 and spin-orbit coupling constant ζ = 5000 cm-1. A discrete variational (DV)-Xα molecular-orbital calculation is carried out for the [I(H2O)6]- ion, which is surrounded by a polarized dielectric continuum. This calculation reproduces the observed spectral parameters and leads to the conclusion that the lowest allowed transition of hydrated iodide ions in aqueous solution is to be ascribed to a Rydberg-type 5p → 6s excitation within the iodide ion, which gives rise to a charge transfer beyond the first solvation sphere (6·8a 0). However, the excitation yields no appreciable charge transfer far beyond the layer of oriented water molecules in immediate contact with [I(H2O)6]-.

Reactions of the hydrogen atom with azide, bromide and iodide ions in aqueous solution

The reactions of H atoms in aqueous solutions with the halides, bromide and iodide and the pseudo-halide, azide, have been investigated. H atoms were conveniently generated in situ using γ-radiolysis. In no case was molecular hydrogen formed as a result of H atoms reacting with these ions. Major products in the azide system are nitrogen and ammonia, a reaction scheme consistent with both our results from product studies under a variety of conditions and reported pulse radiolysis data is proposed. Deuterated propan-2-ol, which reacts with H atoms to form HD, was used to compete with bromide or iodide ions for reaction with H atoms. The dependence of the HD yield on the relative concentrations of halide and propanol was that expected for simple competition. However, our values for the rate constants k(H+Br -) and k(H+I -) of ⩽2×10 4 and 1×10 6 M -1 s -1, respectively, are considerably smaller than those currently given in the literature.

Formation Constants and Structures of Complexes between Cadmium (II) and Iodide Ions in Aqueous Solution

Formation Constants and Structures of Complexes between Cadmium (II) and Iodide Ions in Aqueous Solution

Anthracene sulphonate sensitized photooxidation of iodide ion in aqueous solution via singlet oxygen

The participation of IO 2 in the photosensitized oxidation of 1 − by 1-, 2-, and 1,5-anthracene (A)sulphonates is established by the use of N − 3 as the quencher of the photoreaction. The reaction follows two pathways (i) formation of AO 2 which oxidizes 1 − and (ii) formation of an IO − 2 charge-transfer complex leading to oxidation.

ChemInform Abstract: KINETICS OF REACTION BETWEEN VANADIUM(V) AND IODIDE IONS IN THE PRESENCE OF OXYGEN

AbstractDie Reduktionskinetik von V(V) durch Jodidionen wird in wäßriger Lösung in Gegenwart von Sauerstoff bei 25°C und einer Ionenstärke von 0,4m (NaClO4) untersucht.

Kinetics of reaction between vanadium(V) and iodide ions in the presence of oxygen

The kinetics of reduction of vanadium(V) by iodide ions in aqueous solution have been investigated in the presence of oxygen at 25 °C and ionic strength 0·4M(NaClO4). The results show that the reaction occurs through two parallel paths (i), the first being oxygen-independent, the second involving a molecule of O2. The term b(s–1)v=a+b[O2](i) is given by equation (ii). The mechanism of the oxygen-dependent path involves formation of a peroxovanadium(V)b=(3·3 ± 0·5)× 103[H4VO4+][I–]2[H+]2(ii) intermediate, [VO(O2)]+, which, rapidly reacting with iodide ions, regenerates vanadium(V), VO2+, ions.

Outer-sphere Complex Formation between the Tris(propylenediamine)cobalt(III) Ion and Iodide Ion in Aqueous Solution.

Outer-sphere Complex Formation between the Tris(propylenediamine)cobalt(III) Ion and Iodide Ion in Aqueous Solution.

Outer-sphere Complex Formation between the Hexaamminecobalt(III) Ion and Iodide Ion in Aqueous Solution.

Outer-sphere Complex Formation between the Hexaamminecobalt(III) Ion and Iodide Ion in Aqueous Solution.

Kinetic Study of the Formation and Decomposition of Amylose-iodine-iodide Complex

Abstract The complex formation reaction among amylose, iodine and iodide ion in aqueous solution was investigated with a stopped-flow apparatus. The forward reaction rate was found to be expressed as v=k[Amylose]([I3−]–θ) for [I3−]>θ, where θ is a critical value determining the mechanism. For [I3−]>θ, the rate was considered to be determined by the process between a free amylose unit and free I3−. For [I3−]<θ, the rate-determining step is considered to be intramolecular conversion from an intermediate to a final product. The rate of the reaction between amylose units and I3− is close to that of a diffusion-controlled process (7×108 m−1 sec−1). These conclusions are supported by the study of the decomposition reaction of complex, using Na2S2O3 or Ce(SO4)2.