Ions, in liquids

Turning now to the experimental data, we find that the mobility of the (NH4)+ ion in liquid ammonia does not have any high value that would indicate a contribution from proton jumps.1 Nor docs the (CH,0) ion in methanol or the (C2H5O)- ion in ethanol solution.2 These experimental data do not force us to accept the Hiickel mechanism but if we do not accept the mechanism, we shall have to make some ad hoc assumptions to explain these experimental results. 

Curioni et al.148 studied the protonation of 1,3-dioxane and 1,3,5-trioxane by means of CP molecular dynamics similations. The dynamics of both molecules was continued for few ps following protonation. The simulation provided a detailed picture the evolution of both the geometry and the electronic structure, which helped to rationalize some experimental observations. CP molecular dynamics simulations were applied by Tuckerman et al.149,150 to study the dynamics of hydronium (H30+) and hydroxyl (OH-) ions in liquid water. These ions are involved in charge transfer processes in liquid water H20 H+. .. OH2 - H20. .. H+-OH2, and HOH. . . OH- -> HO-. . . HOH. For the solvatetd H30+ ion, a picture consistent with experiment emerged from the simulation. The simulation showed that the HsO+ ion forms a complex with water molecules, the structure of which oscillates between the ones of H502 and I L/ij clusters as a result of frequent proton transfers. During a consid-... 

Cao, Y. Haseltine, J.N. Busch, K.L. Double Cationization With Alkali Ions in Liquid Secondary lon-MS. Spectroscopy Lett. 1996, 29, 583-589. 

The reaction of 2-chloroquinoline with benzenethiolate ions in liquid ammonia (Amatore et al., 1979a) is a good example for testing the possible occurrence of an Shn2, instead of S l, mechanism, in which the formation of RNu from RX-" and Nu would involve concerted, rather than stepwise, bond breaking and bond formation (Scheme 11). This mechanism... 

Chlorides RMe2CCH2Cl [(a) R = Me, R = Ph and (b) R = CH2Ph] reacted with diphenylphosphide ions in liquid ammonia, via a proposed 5rn 1 mechanism and their reactivities were measured. The higher reactivity of (a) has been attributed to efficient intramolecular electron transfer from the phenyl ring to the C—Cl a bond (intra-ET catalysis). The lower reactivity of (b) is ascribed to a decrease in the rate of the intra-ET by elongation of the bridge by one methylene unit. The relative reactivity of (a) versus (b) is proposed to indicate the ratio of the intra-ET rates of the radical anions of both compounds. ... 

In recent years, experience has shown that a large number of hydrophobic ions could act as ion-exchanger ions in liquid membranes and that almost all water soluble ions not unusually hydrophilic, such as Li, may produce a response in such an ISE. These facts have led to an extraordinary increase in publications in this field, although relatively few of these ISEs have actually been used to solve analytical problems. This field, which is becoming rather confused, will not be discussed in this book and the reader is referred to reviews [103-105]. 

Bio)chemical reactions may take place prior to or after the continuous separation module and are intended to enhance or facilitate mass transfer, detection or both. The earliest and simplest approach to integrated analytical steps in continuous-flow systems involves a combination of chemical reactions and continuous separations [4,5]. Such is the case with the formation of soluble organic chelates of metal ions in liquid-liquid extractions with the ligand initially dissolved in the organic stream [6], the formation and dissolution of precipitates [7], the formation of volatile reaction products in gas difiusion [8] and that of volatile hydrides in atomic absorption spectro-... 

Figure 5 Energy dependence of the density normalized mean free path for e , H, He, and C ions in liquid water. The dotted line shows the water diameter and the dashed line shows the typical spur diameter. (From Ref. 74.)...

J. A. Howard and J. C. Scaiano, Oxyl-, Peroxyl-, and Related Radicals, in Rate and Equilibrium Constants for Reactions of Polyatomic Free Radicals, Biradicals and Radical Ions in Liquids, H. Fischer, Ed., Landolt-Bomstein, New Series n/13, Berlin, 1984, chapter 8. 

Many anionic o-adducts have been described as obtained from the interaction of N-heteroaromatic compounds with the amide ion in liquid ammonia. The reaction is often followed by decomposition leading to overall substitution (amination). This held has been intensively investigated by van der Plas, Zoltewicz, and co-workers. 

Other substrates, in which one of the two nucleofuges is not a halogen, have been studied. Haloarene-diazo sulfides on treatment with arenethiolate ions give substantial formation of bis(arylthio)arenes except that the monofluorophenyl sulfide is produced when the halogen is fluorine,64 and p-iodophenyl-trimethylammonium ion, on treatment with benzenethiolate ion in liquid ammonia, gives p-bis(phenyl-thio)benzene in 95% yield.90... 

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