Complexation with alkali metal salts

In conclusion, polymer electrolytes based on phosphazene backbone and containing ether side chains are, after complexation with alkali metal salts, among the highest ionically solvent-free polymer salt complexes, with conductivities in the order of 10" -10" S cm However, these conductivities are still below the value of 10 S cm" which is considered to be the minimum for practical applications. Therefore the design of new polyphosphazenes electrolytes with a higher conductivity and also a higher dimensional stability still remains a challenge for future researchers. 

Pseudo cyclic ionophores Binary-effect of quinolinyloxy groups at both ends of oligoethylene glycols on the conformational stabilization of their complexes with alkali metal salts, R. Wakita, M. Miyakoshi, Y. Nakatsuki and M. Okahara, J. Inclusion Phenom. Mol. Rec. Chem., 1991, 10, 127. 

Torand 1 (R = butyl) forms remarkably strong complexes with alkali metal salts. Lithium, sodium, potassium, and... 

FLORIAI CZYK, Z., SUCH, K., WIECZOREK, W. and WASIUCIONEK, M., 1991. Highly conductive poly(ethylene oxide)-poly(methyl methacrylate) blends complexed with alkali metal salts. Polymer, 32(18), 3422-3425. 

As mentioned in the Introduction, one of the synthetic approaches to stable nucleophilic carbenes involves C-deprotonation of imidazol-ium and related cations with alkali metal salts of strong bases such as NaH and KO Bu. Accordingly, the interactions with alkali metal cations with stable nucleophilic carbenes could prove to be important for understanding the solution behavior of the latter. Until recently, however, there were no examples of complexes of stable carbenes with... 

Through the isolation of crystalline complexes of dectrically neutral carrier antibiotics with alkali metal salts (10—13) it has become possible to study their detailed structure by X-ray analysis (14). Results... 

Crown ethers can be modified, e.g. 18—crown-6 gave a range of adducts [10] and, what is remarkable, each of these adducts forms complexes with alkali—metal ions. Indeed, in eluting alkali—metal salts over these adducts, adsorbed on nitrocellulose, and then looking at the systems by plasma-desorption mass-spectrometry, none of the uncomplexed adducts could be detected (Becker, J., Odense University, Denmark, unpublished results). The properties of these unusual complexes will be interesting to explore. 

The synthesis of MEEP involves the reaction of poly(dichlorophosphazene) with the sodium salt of methoxy ethoxy ethanol. The byproduct in this reaction is sodium chloride which has to be separated from the polymer completely, since even traces of the ionic impurities would lead to spurious results. However, unfortunately MEEP is also soluble in water and therefore separation from sodium chloride is rendered extremely difficult. A cumbersome and lengthy dialysis procedure is required to effect the separation and purification of the polymer. Further MEEP is also hydrophilic and residual water in the polymer is an undesirable feature for a solid electrolyte particularly when involved with alkali metal salt complexes. Additionally the dimensional stability of MEEP is poor and has been commented upon above. 

Pyranosyl and furanosyl bromides (and chlorides to a lesser extent) react with alkali metal salts of manganate anion to yield the corresponding glycosytoanganese pentacarbonyl complexes. In many instances, the condensation proceeds in excellent... 

Polyethers like poly(ethylene oxide) (PEG) when mixed with alkali metal salts, serve as effective complexing media to yield, often in amorphous form, ionically conducting polymeric solids. The considerable potential permselectivity and excellent redox stability of these newer processible solids is attractive for battery separator applications, and many research groups have been attracted to development of this subject. Armand[60] has published a useful overview of the available polyether conductivity, stability, interfacial kinetic, and ionic transference number literature. 

Binding of hard anions occurs strongly at the hard Lewis acidic uranyl center, whereas cation- tt interactions are established between the aromatic side arms and the cation counterpart of the ion pair. Thus, complexation of alkali metal salts (MX) such as CsCl and RbCl with 15 resulted in the formation of isomorphous supramolecular assemblies in the solid state. In the dimeric [15-CsCl], each cation is coordinated to six oxygens, three from each receptor, thus creating a pseudo-crown-ether-Uke environment for the cation. Additionally, each metal ion in the dimeric unit is coordinated to both halide ions and, most importantly, to two aromatic side arms, one from each of the receptors giving decacoordination for the cation. The closest metal ion-aromatic carbon distances of 3.44(1) A for CsCl, 3.34-3.38(1) A for RbCl, and 3.58(1) A for CsF are observed in the respective alkali halide complexes [15 MX] indicating the conformational flexibility of the side arms and adaptability of the receptors 15 and 16 to form multiple cation- rt interactions with the hosted cations. 

A wide range of soUd and liquid electrolytes has been tested in various electrochromic devices and the results of these studies have been extensively discussed 4). The main dectrolyte groups are aqueous acidic dectrolytes, nonaqueous lidiium dectn tes, ceramic ionic conductms (P-alumina, Nasicon etc.), polyelectrolytes, polyrnCT solid dectrolytes (complexes of polyetfaers or polyimines with alkali metal salts and proton donors) and plasticized polymor ionic conductors. 

Treatment of the dimeric complexes [CpM(CO)n]2 (M = Mo, Fe, and Ni) with alkali metal salts of aromatic hydrocarbons (ArH)"M+ (ArH = naphthalene, anthracene, etc.) causes reductive cleavage, affording a good preparative route ... 

AC conductivity measurements from 10 to 10 Hz were made with a Solartron 1170 Frequency Response Analyzer and polished brass electrodes. The room temperature conductiyities of MgCl2.(PE0) electrolytes are rather low, below 10 (ohm-cm). As the samples are heated, the more dilute materials, n =12, 16, and 24, showed a clear transition to higher conductivities around 60°C, the temperature at which pure PEO melts. Similar behavior has been observed with complexes of alkali metal salts. This transition is suppressed at highjr MgCl2 concentrations (n=4,8). Ionic conductivities of 10 (ohm-cm) are reached by 80 C. 

Simple network structure can further form interpenetrating networks (IPNs). An IPN is a kind of alloy formed by two or more kinds of polymers. In the preparation process, at least one polymer is made during the formation of another kind of polymer. IPNs have a continuous structure with two phases and combines the merits of different polymer materials. This method has been widely used in the preparation of pol uner electrolytes since 1987. For example, epoxy resin (EPO) can be used as a supporting skeleton to provide good mechanical properties. Complexes of linear PEO with alkali metal salt are enclosed in the network during the preparation process of the EPO and are used as channels for ion conduction. At a ratio of EPO to PEO-LiX (11%) of 30 70, the IPN polymer electrolyte has the highest ionic conductivity of about 10 S/cm at 25°C. 

Metathetic substitution with alkali metal salts of transition metal complexes ... 

Derivatives of Antimony Pentabromide and Pentaiodide. The existence of SbBr and Sbl is in doubt, although from time to time they are reported in the Hterature (35). The existence of a 1 1 adduct, SbBr 0(0244 )2, however, is generally accepted. In addition, the SbBr ion is known, and from x-ray studies has been found to have a slightly distorted octahedral stmcture (36). Indeed, there are quite a number of complex bromoantimony compounds with alkali metals and organic bases, some of wliich contain Sb(V). Thus the quinuclidinium salt (C24423N44)4Sb2Br2g is actually made up of... 

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