Iodide salt

Dichlorobutyne [821-10-3] and dibromobutyne [2219-66-1] are readily prepared by treatment with thionyl or phosphoms haUdes. The less-stable diiodobutyne is prepared by treatment of dichloro- or dibromobutyne with an iodide salt (52). 

Lithium Halides. Lithium haHde stabiHty decreases with increasing atomic weight of the halogen atom. Hence, the solubiHty increases from the sparingly soluble Hthium fluoride to the very soluble bromide and iodide salts. The low melting points of Hthium haHdes are advantageous for fluxes in many appHcations. 

Two approaches that have been investigated recently for disinfection are mixtures of bromine and chlorine, and mixtures containing bromide or iodide salts. Some evidence exists that mixtures of bromine and chlorine have superior germicidal properties than either halogen alone. It is believed that the increased bacterial activity of these mixtures can be attributed to the attacks by bromine on sites other than those affected by chlorine. The oxidation of bromide or iodide salts can be used to prepare interhalogen compounds or the hypollalous acid in accordance with the following reaction ... 

Cationic hydrophilic Glycol chitosan, DEAE-dextran, poly(ethyleneimine), poly(trimethylaminoethyl methacrylate) iodide salt 0.5 M acetic acid with 0.3 M NaiSO, or 0.8 M NaNO.,... 

It was recently found that the modification of neutral phosphine ligands with cationic phenylguanidinium groups represents a very powerful tool with which to immobilize Rh-complexes in ionic liquids such as [BMIM][PFg] [76]. The guani-dinium-modified triphenylphosphine ligand was prepared from the corresponding iodide salt by anion-exchange with [NH4][PFg] in aqueous solution, as shown in Scheme 5.2-15. The iodide can be prepared as previously described by Stelzer et al. [73]. 

Metzner et al. also prepared the selenium analogue 17 of their C2 symmetric chiral sulfide and tested it in epoxidation reactions (Scheme 1.6) [8]. Although good enantioselectivities were observed, and a catalytic reaction was possible without the use of iodide salts, the low diastereoselectivities obtained prevent it from being synthetically useful. 

More interesting was the elemental analysis of the residue. Whereas a 2 1 AcOH [DMEpy]l should have contained 33% iodine, the elemental analysis indicated the residue contained only 0.7% iodine. This clearly indicated that we no longer had an iodide salt, but more likely had an acetate salt, most likely a 2 1 mixture of AcOH [DMEpy] [OAc]. (The formation of a 2 1 salt would be typical of our experience with ionic liquids. In practice they normally tenaciously retain ca. 2 mol AcOH/mol of ionic liquid, a phenomena we noted in om earlier reports. (3) Closer comparison of the salt obtained and low levels of Mel detected in the effluent indicated that the amount of [DMEpy] [OAc] generated closely matched the total Mel (ca. 90-95% yield of Mel based on [DMEpy][OAc].) Further, the elemental analysis was unable to detect any Rh in the effluent, so we could conclude that there was no aspiration occurring. This clearly indicated that our ionic liquid loss was due to metathesis of the ionic liquid from the iodide to the acetate salt, likely due to reaction (23) which likely sublimed overhead. In principle, the miniscule amount of Mel and ionic liquid could be returned to the reactor to maintain the process. 

The enantioselectivity of this catalyst, which is prepared as the iodide salt, is somewhat dependent on the anion that is present. If AgSbF6 is used as a cocatalyst, the iodide is removed by precipitation and the e.e. increases from 81 to 91%. These results indicate that the absence of a coordinating anion improved enantioselectivity. Entry 2 shows the extensively investigated f-BuBOX ligand with an A-acryloylthiazolidinone dienophile. With Cu2+ as the metal, the coordination geometry is square planar. The complex exposes the re face of the dienophile. 

Aryl diazonium ions are converted to iodides in high yield by reaction with iodide salts. This reaction is initiated by reduction of the diazonium ion by iodide. The aryl radical then abstracts iodine from either I2 or I3. A chain mechanism then proceeds... 

Fig. 4) related to the 1 1 complex [Br /TCP] [23]. Additions of chloride or iodide salts to the same acceptor also result in the immediate appearance of new absorptions characteristic of the donor/acceptor complexes. Importantly, the band maxima are red-shifted in [r/TCP] and blue-shifted in [cr/TCP] relative to that in [Br /TCP]. 

Other companies (e.g., Hoechst) have developed a slightly different process in which the water content is low in order to save CO feedstock. In the absence of water it turned out that the catalyst precipitates. Clearly, at low water concentrations the reduction of rhodium(III) back to rhodium(I) is much slower, but the formation of the trivalent rhodium species is reduced in the first place, because the HI content decreases with the water concentration. The water content is kept low by adding part of the methanol in the form of methyl acetate. Indeed, the shift reaction is now suppressed. Stabilization of the rhodium species and lowering of the HI content can be achieved by the addition of iodide salts. High reaction rates and low catalyst usage can be achieved at low reactor water concentration by the introduction of tertiary phosphine oxide additives.8 The kinetics of the title reaction with respect to [MeOH] change if H20 is used as a solvent instead of AcOH.9 Kinetic data for the Rh-catalyzed carbonylation of methanol have been critically analyzed. The discrepancy between the reaction rate constants is due to ignoring the effect of vapor-liquid equilibrium of the iodide promoter.10... 

Iodide and acetate salts increase the rate of reaction of Li [1] with CH3I at 25 °C in acetic acid. The effects of water, LiBF4, and other additives are also reported. Iodide salts also promote catalytic methanol carbonylation at low water concentrations. In the case of Lil promoter, lithium acetate is produced. The promotional effects of iodide and acetate on both the model and catalytic systems are rationalized in terms of iodide or acetate coordination to (1) to yield five-coordinate RhI anions as reactive intermediates for rate-determining reactions with CH3I.11... 

The synthesis of the Ni(n) complex of the 13-membered (anionic) macrocycle (78) is also achieved using an in situ procedure (Cummings Sievers, 1970) in which triethylenetetramine, acetic acid, acetylacetone, and nickel acetate are heated in water at the reflux. Addition of iodide ion and adjustment of the pH of the solution to approximately 10, leads to crystallization of the Ni(n) complex of the required cyclized product (78) as its iodide salt. The reaction type has been extended to include Cu(ii) as the template metal (Martin, Wei Cummings, 1972) and has also been... 

In an alternative synthetic procedure, the Ni(n) complex of the depro-tonated form of (81) undergoes rearrangement on heating in water (at 100°C) at pH 5 over 6 hours. Addition of iodide ion and adjustment of the pH to 10 results in precipitation of the corresponding macrocyclic complex (77) as its iodide salt. More recently, the related acid-catalyzed... 

In practice iodide salts of the amino acid complexes are used, as I is lost as Mel under conditions of excess alkylating agent. 

The charge-transfer salts of carbonylmetallates are thus distinguished from the iodide salts in the breadth of photochemistry that obtains upon exposure to visible light. For example, the continuous irradiation of the... 

The DASPE nanoparticles have been synthesized by the ion association reaction between the dye cation (note that the native compound is an iodide salt DASPE-I) and the hydrophobic borate anion (TPB or TFPB-) in the presence of neutral polymer stabilizer polyvinylpyrrolidone (PVP) in aqueous solution [38, 39]. In the absence of PVP, mixing of aqueous TPB- (or TFPB-) and DASPE+ solutions at the same molar fraction yielded the orange opaque solid dispersion composed of the anion-exchanged dye species, DASPE-TPB (or... 

Diethyl N-ethyl-A-arylaminomethylenemalonates (106, R = Et, R2 = H) were heated in phosphoryl chloride at 95-105°C for 3 hr to give quinolinium derivatives, which were isolated as iodide salts (694) [74JAP(K)32933]. 

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