Addition Of Sodium Iodide Research Articles

Rhodium-Catalyzed Formylation of Unactivated Alkyl Chlorides to Aldehydes.

The first rhodium-catalyzed formylation of non-activated alkyl chlorides with syn gas (H2 /CO) allows to produce aldehydes in high yields (25 examples). A catalyst optimization study revealed Rh(acac)(CO)2 in the presence of 1,3-bisdiphenylphosphinopropane (DPPP) as the most active catalyst system for this transformation. Key for the success of the reaction is the addition of sodium iodide (NaI) to the reaction system, which leads to the formation of activated alkyl iodides as intermediates. Depending on the reaction conditions, either the linear or branched aldehydes can be preferentially obtained, which is explained by a different mechanism.

Understanding the role of ancillary ligands in the interaction of Ru(II) complexes with covalent arylamine-DNA adducts

The interaction between Ru(II) complexes and covalent DNA-arylamine adduct has been studied using steady-state fluorescence spectroscopy. Here, we have used 16-mer NarI sequences with variation in next flanking bases i.e., -CG1G2CG3CX- in which X is either C or T and G is unmodified or N-acetylaminofluorene-dG (AAF-dG). To understand the effect of ancillary ligands, we used three Ru(II) complexes [Ru(phen)2(dppz)]2+ (Ru-1), [Ru(TMP)2(dppz)]2+ (Ru-2)and [Ru(DIP)2(dppz)]2+(Ru-3) [where phen: 1,10-phenanthroline; TMP: 3,4,7,8-tetramethyl-1,10-phenanthroline; DIP: 4,7-diphenyl-1,10-phenanthroline; dppz: dipyrido[3,2-a;2′,3′-c]phenazine]. Steady-state luminescence data shows that all the three complexes exhibit strong luminescence when it binds to AAF-dG adducts compared to unmodified control. The addition of sodium iodide to the binary mixture (Ru-oligo) improves the luminescence differential in G1 and G3 AAF adducts while it is minimal at G2. Competitive binding studies also show that the ancillary ligand in the complex Ru-2 alters the binding towards the adducted site compared to Ru-1 and Ru-3. Overall, the present study reveals that the probing of adducted site by Ru(II) complexes is dictated not only by the conformational heterogeneity of the AAF-dG adduct but ancillary ligands as well.

Compatible Solid Polymer Electrolyte Based on Methyl Cellulose for Energy Storage Application: Structural, Electrical, and Electrochemical Properties.

Compatible green polymer electrolytes based on methyl cellulose (MC) were prepared for energy storage electrochemical double-layer capacitor (EDLC) application. X-ray diffraction (XRD) was conducted for structural investigation. The reduction in the intensity of crystalline peaks of MC upon the addition of sodium iodide (NaI) salt discloses the growth of the amorphous area in solid polymer electrolytes (SPEs). Impedance plots show that the uppermost conducting electrolyte had a smaller bulk resistance. The highest attained direct current DC conductivity was 3.01 × 10−3 S/cm for the sample integrated with 50 wt.% of NaI. The dielectric analysis suggests that samples in this study showed non-Debye behavior. The electron transference number was found to be lower than the ion transference number, thus it can be concluded that ions are the primary charge carriers in the MC–NaI system. The addition of a relatively high concentration of salt into the MC matrix changed the ion transfer number from 0.75 to 0.93. From linear sweep voltammetry (LSV), the green polymer electrolyte in this work was actually stable up to 1.7 V. The consequence of the cyclic voltammetry (CV) plot suggests that the nature of charge storage at the electrode–electrolyte interfaces is a non-Faradaic process and specific capacitance is subjective by scan rates. The relatively high capacitance of 94.7 F/g at a sweep rate of 10 mV/s was achieved for EDLC assembly containing a MC–NaI system.

Pyrazine derivatives as green oil field corrosion inhibitors for steel

The inhibitive efficacy of environmental friendly pyrazine derivatives, 2,3-pyrazine dicarboxylic acid (Pyrazine C), pyrazine carboxamide (Pyrazine E) and 2-methoxy-3-(1-methylpropyl) pyrazine (Pyrazine H), on X60 steel were investigated in 15% hydrochloric acid (HCl), which simulate oil well acidizing conditions. The inhibitors were examined for their inhibition performance utilizing weight loss measurement at 60 °C and 90 °C for 6 h and electrochemical methods namely potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LPR) at 25 °C. Results showed that efficiencies of pyrazines C and E were not affected by increase in their concentrations at 60 °C, however inhibition performance of pyrazine E increased with concentration at 90 °C while pyrazine C remained unchanged. The inhibition performance of pyrazine H increased with concentration at both temperatures. It was observed that addition of sodium Iodide (NaI) and Glutathione (Glu) enhanced the inhibition performance of pyrazine C and E but has no significant effect on pyrazine H. Potentiodynamic test showed that the three pyrazine derivatives investigated are mixed typed inhibitors. Pyrazine C and H are predominantly cathodic whereas pyrazine E was shown to be predominantly anodic. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) spectroscopy were utilized to further confirm the inhibition of steel corrosion by the three pyrazine derivatives.

An Unusual Salt Effect in an Interfacial Nucleophilic Substitution Reaction.

This paper reports a kinetic characterization of the interfacial reaction of N-methylpyrrolidine with a self-assembled monolayer presenting an iodoalkyl group. SAMDI (self-assembled monolayers for matrix-assisted laser desorption/ionization) mass spectrometry was used to determine the extent of reaction for monolayers that were treated with a range of concentrations of the nucleophile for a range of times. These data revealed a second-order rate constant for the reaction that was approximately 100-fold greater than that for the analogous solution-phase reaction. However, addition of sodium iodide to the reaction mixture resulted in a 7-fold decrease in the reaction rate. Addition of bromide and chloride salts also gave slower rate constants for the reaction, but only at 100- and 1000-fold higher concentrations than was observed with iodide, respectively. The corresponding solution-phase reactions, by contrast, had rate constants that were unaffected by the concentration of halide salts. This work provides a well-characterized example illustrating the extent to which the kinetics and properties of an interfacial reaction can depart substantially from their better-understood solution-phase counterparts.

Comprehensive studies on polymer electrolyte and dye-sensitized solar cell developed using castor oil-based polyurethane

Comprehensive characterization of new polymer electrolyte system prepared using polyurethane derived from castor oil polyol was undertaken. The castor oil polyol was synthesized via transesterification and reacted with 4,4′-diphenylmethane diisocyanate to form polyurethane. Polyurethane electrolyte films were prepared by addition of sodium iodide in different weight percentage with respect to the weight of the polymer. The electrolyte films were analyzed using Fourier transform infrared spectroscopy, dynamic mechanical analysis, electrochemical impedance spectroscopy, transference number measurement, and linear sweep voltammetry. Fourier transform infrared spectroscopy results confirmed the complexation between polymer and salt. Tan delta peak observed in the tan δ–temperature curve plotted using data obtained from dynamic mechanical analysis indicated that the glass transition temperature of polyurethane decreased with the addition of sodium iodide. The highest conductivity of 4.28 × 10−7 S cm−1 was achieved for the film with 30 wt% of sodium iodide. The performances of dye-sensitized solar cell using the electrolyte systems were analyzed in terms of short-circuit current density, open-circuit voltage, fill factor, and energy conversion efficiency. The polymer electrolyte with 30 wt% sodium iodide showed the best performance with energy conversion efficiency of 0.80%.

The Role of the Pediatrician in Preventing Congenital Malformations

The Role of the Pediatrician in Preventing Congenital Malformations

Sodium Iodide

Sodium iodide (NaI) occurs as colorless, odorless or as a white crystalline solid; it is slightly hygroscopic, and a commercially available reagent. It is soluble in water, ­alcohols, acetone, and other organic solvents and stable under normal temperature and pressure (mp: 651 ˚C, d = 3.67 g/cm³). [¹] On a laboratory scale, sodium iodide may be prepared by neutralizing a solution of sodium hydroxide or sodium carbonate with hydriodic acid. [²] Sodium iodide is a very useful and versatile reagent for the synthesis of various types of organic compounds. For example, an important application of this reagent involves the conversion of an alkyl chloride or alkyl bromide to an alkyl iodide by the addition of sodium iodide in acetone (Scheme [¹] ). [³] This nucleophilic substitution reaction, also known as Finkelstein reaction, may proceed via either an SN1 or SN2 mechanism depending on the nature of the alkyl halide. [4] [5]

A model for additive transport in metal halide lamps containing mercury and dysprosium tri-iodide

The distribution of additives in a metal halide lamp is examined through numerical modelling. A model for a lamp containing sodium iodide additives has been modified to study a discharge containing dysprosium tri-iodide salts. To study the complex chemistry the method of Gibbs minimization is used to decide which species have to be taken into account and to fill lookup tables with the chemical composition at different combinations of elemental abundance, lamp pressure and temperature. The results from the model with dysprosium additives were compared with earlier results from the lamp containing sodium additives and a simulation of a pure mercury lamp. It was found that radial segregation creates the conditions required for axial segregation. Radial segregation occurs due to the unequal diffusion of atoms and molecules. Under the right conditions convection currents in the lamp can cause axial demixing. These conditions depend on the ratio of axial convection and radial diffusion as expressed by the Peclet number. At a Peclet number of unity axial segregation is most pronounced. At low Peclet numbers radial segregation is at its worst, while axial segregation is not present. At large Peclet numbers the discharge becomes homogeneously mixed. The degree of axial segregation at a Peclet number of unity depends on the temperature at which the additive under consideration fully dissociates. If the molecules dissociate very close to the walls no molecules are transported by the convective currents in the lamp, and hence axial segregation is limited. If they dissociate further away from the walls in the area where the downward convective currents are strongest, more axial segregation is observed.

A Facile and Efficient Deoxygenation of Amine-N-oxides with WCl6/NaI System

The deoxygenation of amine-N-oxides to amines is an important transformation in the synthesis of nitrogenous aromatic heterocycles and an area of considerable interest, particularly when a molecule has other reducible or labile moieties. A number of methods have been described for the reduction of amine-N-oxides, including agents such as low-valent titanium, Zn/HCOONH4, InCl3, tributyltinhydride, Pd/C, SmI2, tetrathiomolybdate, indium/NH4Cl, Mo(CO)6. However, many of these methods are deficient in some respects such as relatively severe reaction conditions, low yields, poor selectivity or occurrence of side reactions. Consequently, there is still a need for introducing selective and mild reagents for the deoxygenation of amineN-oxides to amines. In continuation of our efforts towards the development of the low-valent metal reagents for organic transformations, we observed that a combination of WCl6 with sodium iodide could bring about the deoxygenation of amine-N-oxides under mild conditions. The new reducing system was generated by the addition of sodium iodide to a stirred solution of tungsten hexachloride in acetonitrile under nitrogen atmosphere. In this communication, we wish to report an efficient and chemoselective method for the deoxygenation of various amine-N-oxides to the corresponding amines by treatment with WCl6/NaI system in aceto-

Highly Active Chiral Ruthenium Catalysts for Asymmetric Ring-Closing Olefin Metathesis

The synthesis of olefin metathesis catalysts containing chiral, monodentate N-heterocyclic carbenes and their application to asymmetric ring-closing metathesis (ARCM) are reported. These catalysts retain the high levels of reactivity found in the related achiral variants (1a and 1b). Using the parent chiral catalysts 2a and 2b and derivatives that contain steric bulk in the meta positions of the N-bound aryl rings (catalysts 3-5), five- through seven-membered rings were formed in up to 92% ee. The addition of sodium iodide to catalysts 2a-4a (to form 2b-4b in situ) caused a dramatic increase in enantioselectivity for many substrates. Catalyst 5a, which gave high enantiomeric excesses for certain substrates without the addition of NaI, could be used in loadings of < or =1 mol %. Mechanistic explanations for the large sodium iodide effect as well as possible mechanistic pathways leading to the observed products are discussed.

Structure and Vibrational Spectroscopy of Salt Water/Air Interfaces: Predictions from Classical Molecular Dynamics Simulations

We report the sum frequency generation (SFG) spectra of aqueous sodium iodide interfaces computed with the methodology outlined by Morita and Hynes (J. Phys. Chem. B 2002, 106, 673), which is based on molecular dynamics simulations. The calculated spectra are in qualitative agreement with experiment. Our simulations show that the addition of sodium iodide to water leads to an increase in SFG intensity in the region of 3400 cm(-1), which is correlated with an increase in ordering of hydrogen-bonded water molecules. Depth-resolved orientational distribution functions suggest that the ion double layer orders water molecules that are approximately one water layer below the Gibbs dividing surface. We attribute the increase in SFG intensity to these ordered subsurface water molecules that are present in the aqueous sodium iodide/air interfaces but are absent in the neat water/air interface.

Synthesis and structure of alkynylplatinum(IV) complexes containing the pincer group [2,6-(dimethylaminomethyl)phenyl- N, C, N] −

Reaction of phenyl(trimethylsilylalkynyl)iodine(III) triflate with Pt II(O 2CAr)(NCN) (Ar = Ph, 4-trifluoromethylphenyl (Ar F); NCN = [C 6H 3(CH 2NMe 2) 2-2,6]) at ambient temperature gives solutions of Pt IV(O 2CAr)(OTf)(C CSiMe 3)(NCN) [Ar = Ph ( 1a); Ar = Ar F ( 1b)]. Addition of sodium iodide (NaI) to 1 results in the isolation of Pt IV(O 2CAr)I(C CSiMe 3)(NCN) [Ar = Ph ( 2a); Ar = Ar F ( 2b)] in >90% yields. In these first examples of alkynyl(pincer)platinum(IV) complexes, the pincer group is present as a mer-[NCN] − tridentate donor and the alkynyl group is located cis to the pincer carbon donor, and the triflate ( 1a, 1b) and iodide groups ( 2a, 2b) are located trans to the pincer carbon; an X-ray structural analysis has been completed for 2b.

Hydrosilylation of Alkynes with a Cationic Rhodium Species Formed in an Anionic Micellar System.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Reactivity of Diaryliodine(III) Triflates toward Palladium(II) and Platinum(II): Reactions of C(sp2)−I Bonds to Form Arylmetal(IV) Complexes; Access to Dialkyl(aryl)metal(IV), 1,4-Benzenediyl-Bridged Platinum(IV), and Triphenylplatinum(IV) Species; and Structural Studies of Platinum(IV) Complexes

Diphenyliodine(III) triflate is able to transfer Ph+ to Pd(II) and Pt(II) with cleavage of a phenyl−iodine bond and formation of metal(IV) species, leading to the first identified transfer of Ph+ to Pd(II) from an aryl−halogen bond, and, for platinum, a methodology providing a facile route to dimethyl(aryl)platinum(IV) and 1,4-arenediyl-bridged Pt(IV) species and the first archetypal triarylplatinum(IV) complex. Thus, [IPh2][OTf] reacts with PtMe2(bpy) (bpy = 2,2‘-bipyridine) at −50 °C to form iodobenzene and the Pt(IV) complex trans-PtIV(OTf)Me2Ph(N∼N) (1b) (Ph trans to OTf), and on addition of NaI, the species PtIMe2Ph(bpy) (2a (Ph cis to I) and 2b (Ph trans to I) in 2:1 ratio) may be isolated at −20 °C. Similarly, metalla(II)cyclopentane complexes M(C4H8)(bpy) react with [IPh2][OTf] to form trans-Pt(OTf)(C4H8)Ph(bpy) (3b) and a 1:1 ratio of cis- (4a) and trans-Pd(OTf)(C4H8)Ph(bpy) (4b); addition of halide ion gives trans-PtI(C4H8)Ph(bpy) (5b) and a 1:3 ratio of cis and trans isomers for PdI(C4H8)Ph(bpy) (6a, 6b) and PdCl(C4H8)Ph(bpy) (7a, 7b). Complex 5b isomerizes to form a 2:1 mixture of cis-PtI(C4H8)Ph(bpy) (5a) and 5b at ambient temperature in acetone. Dimethyl(2,2‘-bipyridine)palladium(II) reacts with [IPh2][OTf] to form Pd(OTf)Me2Ph(bpy), followed by transfer of a methyl group from Pd(IV) to Pd(II), to form trimethylpalladium(IV) species. Dimethyl(2,2‘-bipyridine)platinum(II) reacts with [IPh(C6H4-4-I)][OTf], followed by addition of sodium iodide, to form a 1:1 mixture of trans-PtIMe2Ph(bpy) (2b) and trans-PtIMe2(C6H4-4-I)(bpy) (8b), and with [IPh(C6H4-4-IPh)][OTf]2 to form the 1,4-arenediyl complex trans-1,4-{PtIMe2(bpy)}2C6H4 (9b). Diphenyl{di(tert-butyl)-2,2‘-bipyridine}platinum(II) reacts with [IPh2][OTf] at 25 °C over 2 days to form the triphenylplatinum(IV) complex Pt(OTf)Ph3(But2bpy) (10), and addition of iodide ion results in isolation of PtIPh3(But2bpy) (11). Structural studies of trans-PtIMe2Ph(bpy) (2b) and trans-Pt(C4H8)Ph(bpy) (5b) reveal distorted octahedral geometry and the fac-PtC3 configuration expected for all of the metal(IV) complexes. The compound [IPh(C6H4-4-I)][OTf] has two sets of cation−anion pairs with a complex array of weak interactions, and the cations have C−I−C angles close to 90°.

Hydrosilylation of alkynes with a cationic rhodium species formed in an anionic micellar system.

[reaction: see text] Rhodium-catalyzed hydrosilylation of alkynes in an aqueous micellar system has been developed. A combination of [RhCl(nbd)](2) and bis(diphenylphosphino)propane (dppp) effects (E)-selective hydrosilylation in the presence of sodium dodecyl sulfate (SDS) in water. The (E)-selectivity strongly indicates the formation of a cationic rhodium species via dissociation of the Rh-Cl bond by the action of anionic micelles. The addition of sodium iodide provided (Z)-alkenylsilanes predominantly.

Effect of sodium iodide additive on the electrochemical performance of sodium/nickel chloride cells

The effect of sodium iodide and sulfur additives on the performance of Na/β′′-alumina/NaAlCl4/NiCl2/Ni cells was investigated in quasi-sealed laboratory research cells (0.5–1.0 Ah capacity) and in sealed full-size cells (4 Ah capacity). It was found that sodium iodide additive especially in combination with sulfur in Na/NiCl2 cells significantly increases the usable capacity and reduces the impedance of the Na/NiCl2 cells. It is proposed that the use of sodium iodide enhances the energy and power performance of the NiCl2 electrode by two different mechanisms. The first mechanism, iodide ion doping of the anodically formed solid NiCl2, is dominant at potentials lower than that of iodine evolution. The doping effect of the iodide ions produces a higher-capacity, lower-impedance NiCl2 layer on the positive electrode. The second mechanism, anodic formation of very reactive iodine species, is effective when the cell is cycled through the iodine evolution potential range (2.8–3.1 V vs Na). During this process, the dissolved iodine species improve electrode kinetics through liquid-phase mass transport. Use of the sodium iodide additive is safe in sealed cells, causing no over-pressurizing problems. A maximum pressure increase of only 10 kPa was detected by a pressure sensor during severe overcharge tests.

Radical Additions of Alkyl 2‐Haloalkanoates and 2‐Haloalkanenitriles to Alkenes Initiated by Electron Transfer from Copper in Solvent‐Free Systems

AbstractAlkyl 2‐iodoalkanoates 2, and 2‐iodoalkanenitriles 15 were added, with copper powder, to the 1‐alkenes 1a, e, f, and h, and to the alkenes 1b, c, d, and g with a 1,2‐dialkyl substituted double bond, to give, respectively, γ‐lactones and 4‐iodoalkanenitriles in very good yields. No solvent was used. The reaction is a free radical addition initiated by electron transfer from copper to the activated iodoalkane. Yields were lower using the respective bromo compounds. In situ formation of the iodo compounds, by addition of stoichiometric amounts of sodium iodide to the reaction mixture, gave improved yields. In the case of the methyl bromomalonates 6, the addition of sodium iodide proved to be unnecessary. The diastereoselectivity of the addition reaction by relative 1,3‐asymmetric induction was rationalized by consideration of the steric interactions of the substituents in the transition state which is formed in the process of iodine transfer to the chiral adduct radical.

2,6-Dimethylphenol polymerization with cuprous chloride andn-butylamine catalyst system: Effect of Nal addition

2,6-Dimethylphenol polymerization with catalyst systems based on CuCl/n-butylamine were studied under 10 kg/cm2 pure oxygen pressure. By addition of sodium iodide, the catalyst performance was dramatically improved and an unusual long induction period was observed. Both the polymer intrinsic viscosity obtained and the induction period increased significantly with the increase of NaI concentration. However, the induction period decreased rapidly with the increase of n-butylamine concentration. UV-VIS absorption spectra showed that the CuCl/n-butylamine complex was converted to Cul/n-butylamine complex after the addition of NaI. The hydration rate of copper halide/n-butylamine complex decreased significantly with the increase of NaI and n-butylamine concentrations. Therefore the increase of polymer intrinsic viscosity and induction period by NaI addition suggest that the polymerization catalyst became more hydrolytically stable and less active at the higher NaI concentration. © 1996 John Wiley & Sons, Inc.

2,6‐Dimethylphenol polymerization with cuprous chloride and n‐butylamine catalyst system: effect of Nal addition

2,6-Dimethylphenol polymerization with catalyst systems based on CuCl/n-butylamine were studied under 10 kg/cm2 pure oxygen pressure. By addition of sodium iodide, the catalyst performance was dramatically improved and an unusual long induction period was observed. Both the polymer intrinsic viscosity obtained and the induction period increased significantly with the increase of NaI concentration. However, the induction period decreased rapidly with the increase of n-butylamine concentration. UV-VIS absorption spectra showed that the CuCl/n-butylamine complex was converted to Cul/n-butylamine complex after the addition of NaI. The hydration rate of copper halide/n-butylamine complex decreased significantly with the increase of NaI and n-butylamine concentrations. Therefore the increase of polymer intrinsic viscosity and induction period by NaI addition suggest that the polymerization catalyst became more hydrolytically stable and less active at the higher NaI concentration. © 1996 John Wiley & Sons, Inc.