N-butylammonium Iodide Research Articles

A new electrochemically formed, iodide-modified platinum electrode usable to −3 V versus SCE in dimethylformamide. Preliminary studies of the reduction of alkyl bromides and chlorides

A new kind of modified platinum electrode can be created if the electrode is cathodically polarized in dimethylformamide containing 0.10 M tetra- n-butylammonium tetrafluoroborate and small amounts of tetra- n-butylammonium iodide, if the medium has been previously dried in situ with activated alumina, and if the polarized electrode is subsequently exposed to oxygen for a few minutes. Cyclic voltammograms recorded with this modified electrode display a remarkably low residual current and exhibit a cathodic potential limit of −3 V versus SCE. Using such a modified electrode, we have observed well-defined cyclic voltammetric waves for the reductive cleavage of 1-bromopropane and 1-chlorooctane, two compounds that cannot be reduced at unmodified platinum cathodes.

Syntheses, structures and reactivities of [Os 6Pd(CO) 18(bipy)] and [{(bipy)Pd}20s 3(CO) 12]: Crystal and molecular structures of [{(bipy)Pd} 2(μ-H)(μ-CO)][H 3Os 4(CO) 12] and [(C 4H 9) 4N] 2[Pd 2I 6

The complex [(bipy)Pd(C0 2Me) 2] reacts with [Os 3(CO) 10(NCMe) 2] in a 1 : 1 molar ratio to give [Os 6Pd(CO) 18(bipy)] ( 1) with a moderate yield, and the crystal structure of 1 is presented. Complex 1 is separately treated with an excess of iodine and tetra- n-butylammonium iodide, giving0 [Os 6(CO) 18] and [( nBu) 4N] 2[Pd 2I 6] ( 2) respectively. Complex 2 is characterized by X-ray crystallography. The cyclic voltammogram of 1 reveals an irreversible oxidation at a potential of around 0.75 V and no reduction wave is observed. On the contrary, the reaction of [(bipy)Pd(CO 2Me) 2] with [H 2OS 3(CO) 10] in a 1:2 molar ratio gives [{(bipy)Pd) 2}Os 3(CO) 12) ( 3) with a 25% yield. The X-ray crystallographic study of 3 reveals a stacking situation of the molecules along the c axis. Treatment of 3 with an excess of chloride salt leads to the formation of the cationic species [{(bipy)Pd} 2(μ-H)(μ-CO)] + ( 4) the [H 3Os 4(CO) 12] − salt of which is isolated. Again, a stacking of the dinuclear cations is observed from the X-ray structural analysis of 4.

Ion-pair reversed-phase thin-layer chromatography of organic acids : Re-investigation of the effects of solvent pH on R F values

The effect of solvent pH on the ion-pair reversed-phase thin-layer chromatography of four organic acids (salicylic acid, gentisic acid, 2,5- and 2,6-dihydroxybenzoic acid) has been re-investigated. These acids were chromatographed on silica gel, paraffin-impregnated silica gel and on C 18-bonded silica gel with a total of four ion-pair reagents. The R F of these compounds were unaffected by solvent pH when tetra - n-butylammonium iodide and tetraheptylammonium bromide were used as ion- pair reagents. However, when cetrimide and cetyltrimethylammonium bromide were used a significant dependence of R F on the solvent pH was observed. Some possible explanations for the observed differences between these ion-pair reagents are discussed, together with the potential usefulenss of this phenomenon.

Conductimetric investigations on salts in N,N-dimethylthioformamide at 25° C

Conductimetric measurements have been performed on solutions of the following salts in N,N-dimethylthioformamide (DMTF) at 25°C:- tri isoamyl- n-butylammonium tetraphenylborate, tri isoamyl- n-butylammonium iodide, tri isoamyl- n-butylammonium perchlorate, tetra- n-butylammonium tetraphenylborate, tetra- n-butylammonium iodide, tetra- n-butylammonium perchlorate, bis(DMTF)copper(I)chloride, bis(DMTF)copper(I) bromide, bis(DMTF)copper(I) iodide, tetrakis(DMTF)copper(I) perchlorate, bis(DMTF)silver(I) chloride, bis(DMTF)silver(I) bromide and (DMTF)silver(I) iodide. The data have been analysed with the Pitts and the Fuoss—Justice conductivity equations and single ion conductivities have been calculated based on the assumption of equal limiting anion and cation conductivities for tri isoamyl- n-butylammonium tetraphenylborate.

Spectroscopic studies of the ion-pair interactions of antimony(III)

Various types of ion-pairs of different systems involving tetra- n-butylammonium iodide (D) with antimony trichloride (A) in dilute solutions in acetonitrile, methylene chloride and chloroform have been investigated spectrophotometrically in the region 550—25O mn. Their composition, stability constant, and free energy of formation have been calculated. The stability constant of the complex is related very much to its stoichiometry. The complex of acetonitrile system has the form D.A 2 whereas D.A is the form of methylene chloride and chloroform systems. The energy difference of the two peaks of the spectrum was compared with the 2 P 3 2 — 2 P 1 2 energy interval of the iodine atom. A comparison of the stability values has been discussed in relation to the polarizability and the dielectric constant of the environment used. A model attained by the ion in the solution may play a considerable role in the mechanism of ion-pairs interaction.

Cleavage of methyl and benzyl ethers with thiotrimethylsilanes

The reagents methylthio-, phenylthio- or 1,2-ethanedithiobis- trimethylsilane in combination with zinc iodide and tetra n-butylammonium iodide effect de-O-alkylation of methyl and benzyl ethers under relatively mild conditions. Ester functions are unaffected and no iodides are formed in the cases studied.