Predictions complex ions reactions

The aluminium ion, charge -I- 3. ionic radius 0.045 nm, found in aluminium trifluoride, undergoes a similar reaction when a soluble aluminium salt is placed in water at room temperature. Initially the aluminium ion is surrounded by six water molecules and the complex ion has the predicted octahedral symmetry (see Table 2.5 ) ... 

Pourbaix diagrams are only thermodynamic predictions and yield no information about the kinetics of the reactions involved nor are the influences of other ionic species which may be present in the solution included. Complexing ions, particularly haUdes, can interfere with passivation and can influence... 

Intramolecular Isotope Effects. The data in Figure 2 clearly illustrate the failure of the experimental results in following the predicted velocity dependence of the Langevin cross-section. The remark has been frequently made that in the reactions of complex ions with molecules, hydrocarbon systems etc., experimental cross-sections correlate better with an E l than E 112 dependence on reactant ion kinetic energy (14, 24). This energy dependence of reaction presents a fundamental problem with respect to the nature of the ion-molecule interaction potential. So far no theory has been proposed which quantitatively predicts the E l dependence, and under these circumstances interpreting the experiment in these terms is questionable. 

In complex organic molecules calculations of the geometry of excited states and hence predictions of chemiluminescent reactions are very difficult however, as is well known, in polycyclic aromatic hydrocarbons there are relatively small differences in the configurations of the ground state and the excited state. Moreover, the chemiluminescence produced by the reaction of aromatic hydrocarbon radical anions and radical cations is due to simple one-electron transfer reactions, especially in cases where both radical ions are derived from the same aromatic hydrocarbon, as in the reaction between 9.10-diphenyl anthracene radical cation and anion. More complex are radical ion chemiluminescence reactions involving radical ions of different parent compounds, such as the couple naphthalene radical anion/Wurster s blue (see Section VIII. B.). 

Consider the endothermic reaction Fe3+(aq) + Cl (aq) FeCl2+(aq). Use Le Chatelier s principle to predict how the equilibrium concentration of the complex ion FeCl2+ will change when ... 

Hexachloroiridate ion, IrClJ-, is a complex inert to substitution and is known to undergo outer-sphere electron transfer with other inorganic species (cf. Cecil and Littler, 1968). Some of its reactions have been treated in Tables 12 and 14 and shown to be of the non-bonded electron-transfer type. Its reaction with various alkylmetals has been thoroughly studied, and some results are shown in Table 16 (entries nos. 14 and 15). Except for sterically hindered tetralkyltins the Marcus theory makes incorrect predictions for these reactions, and non-bonded electron transfer does not appear to be feasible. 

The Cu ion is classified as a soft acid (see Hard Soft Acids and Bases), which predicts reasonably well the types of ligands that will be most stabilizing and are, thus, commonly observed in Cu complexes. The preference of Cu for softer ligands is quite apparent in the homoleptic complexes, for instance the halides discussed above. Polynuclear compounds are quite commonly seen in the chemistry of Cn. Thus, the solid-state structure cannot be reliably predicted from the reaction stoichiometry or from the empirical formula of the resulting compound. The careful selection of ligands, for instance, an appropriate macrocyclic ligand can ensnre the formation of a mononuclear complex if one is desired. 

The calculation procedures ascribed above have practical importance. They can be employed to predict the distribution ratio of a metal ion, DJJ, between the bulk solution phase and the ion-exchanger phase. The distribution proRles at various pH s and salt concentrations can be estimated just by use of the unique microscopic stability constant, (Pi)q, if the monodentate complex formation reaction is predominant. With dehned as the ratio of the amount of the bound metal ions to the total capacity of the carboxydate ion exchanger is related to the intrinsic binding constant, K, as shown... 

Values of Krat 25°C for several complex ion equilibria are given in Table 11.5 in the text -> Fonnation and solubility reactions may be combined to predict the solubility of a salt in the presence of a species that forms a complex with the metal ion. 

In addition to the microsolvation, the effect of solvation on the reaction has also been modeled by Re and Morokuma [111]. They demonstrated the significance of molecular solvation using the two-layered ONIOM method. The Sn2 pathway between CH3CI and OH ion in microsolvated clusters with one or two water molecules has been studied. This work highlighted the role of solvent in the chemical reaction and also the power of ONIOM model to predict complex systems. All these studies have undoubtedly brought out the significance of H-bonding in solute-solvent interaction, chemical reactivity, and molecular solvation phenomenon. 

We can actually see the process of electron pair shift with a resultant change in structure in the complex ion [Co(diars)2NO)J+ (where diars is a bidentale diarsine ligand) (Fig. 15.17). The 18-electron rule predicts that the nitrosyl group will be linear (a three-electron donor), as indeed it is. Reaction of this complex with the thiocyanate ion (a two-electron donor) would violate the 18-electron rule unless a pair is shifted from a molecular orbital of largely metal character to an orbital on nitrogen. This is in fact what happens and stereochemical control of valence" results.47 As NO goes from being a three-electron to a one-electron donor, a coordination site capable of... 

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