Methanol halide interaction with

Z values are both temperature- and pressure-dependent. The CT absorption band of substituted pyridinium halides is shifted hypsochromically as the temperature of the solution is decreased [59]. Thus, Z values decrease with increasing temperature due to a lowering of the solute/solvent interactions at the higher temperature. Furthermore, it has been shown that the CT absorption band of l-ethyl-4-(methoxycarbonyl)-pyridinium iodide is shifted bathochromically for solutions in methanol and ethanol with increasing pressure (up to 1920 bar), while for other solvents such as acetone and A, A -dimethylformamide it is shifted hypsochromically [60]. Except for the lower alcohols, the bulk solvent polarity generally increases with pressure [60]. 

Addition of NaBr to a solution containing Pd(OAc)2 and 9S3 in methanol gives the orange-brown [PdBr2(9S3)] complex (Eq. 11c), in which Pd(II) interacts with two halide ions and a tridentate 9S3 to yield square pyramidal coordination (Fig. 6 Table 1) [106]. As in the bis(9S3) complex, the coordination sphere contains a semi-coordinated S atom in the apical position [106]. The chloride analogue [137] has a similar structure. 

An EMF method has been used to study the interaction of ZnCl2 with chloride ion in methanol. It is found that Kx (7.76 x 103 M) is less than K2 (1.74 x 104 M), a finding which is interpreted in terms of passing from an octahedral [ZnCl(MeOH)5]+ species to a tetrahedral [ZnCl2(MeOH)2] complex.967 Related studies have shown that the solubility of cadmium halides in water decreases with increasing pressure.968 969 Anionic [ZnCl3] and [ZnCU]2-species are present in zinc chloride battery electrolyte, and are responsible for the observed negative transference numbers for zinc in aqueous acidic chloride medium.970 In neutral... 

Oxidation of M(CO)6 with halogens affords M2(CO)gXj anions, but in the presence of PMe3, neutral mononuclear species MX(CO)3(PMe3)3 are formed. The former contain three bridging halide atoms, which can be substituted by MeO or CH3C02 by reaction with methanol or acetic acid. The metal-metal distance of over 3.5 A precludes direct interaction. The dinuclear chloro anions are converted to CpM(CO)4 by reaction with LiCp and to (i76-arene)M(CO)4+ in the presence of arene and AlBr3. 

The combination of Metastable Impact Electron Spectroscopy (MIES) and Ultraviolet Photoelectron Spectroscopy, UPS(Hel) has been applied to the study of the interaction between halides (Csl, CsF, and Nal) with solid water and methanol around their respective Tg values [11,12]. Surface segregation of iodide, but not of fluoride or Cs ions, took place from ASW, exposed to Csl or CsF vapour, during annealing [11]. The same behaviour was also derived from molecular dynamics (MD) simulations of the corresponding aqueous salt solutions. In contrast, no appreciable surface segregation of ions was observed in methanol under similar conditions, neither in the experiment nor in the simulation of the corresponding liquid solution. It was pointed out that, as far as solvation phenomena are concerned, water and methanol ices, when heated above their respective Tg values, behave remarkably similar to the corresponding liquid solutions. The surface propensity of iodide is also seen when Cs is replaced by Na [12]. 

In the present report, we present a more through-out analysis of the data for the interaction of halides with solid water and methanol films, in particular those of ref. [12]. This leads to a deepened understanding of the analogy observed between amorphous solids above their Tg and their respective liquid counterparts. 

According to Fig. 7.3.1 the isotherm slopes are approximately equal in formamide and methanol whereas the slope for the aqueous system is considerably larger. The mutual repulsion of adsorbed anions is therefore evidently stronger in methanol and formamide than in water. The interaction parameter is also found to depend strongly on the anion for a given solvent. For example in the formamide system the second virial coefficient (which is directly related to the interaction parameter) for adsorption of 1 ions is 310 A /ion compared with 2000 A /ion for Cl ions. Thus the simple adsorption model of point charges undergoing lateral coulombic repulsion represents a considerable oversimplification in non-aqueous solutions as in aqueous solutions. Studies of adsorption of halide anions from mixed electrolyte solutions in formamide and methanoF reveal complex behaviour which cannot be explained in terms of a simple model. 

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