Alkali ternary

The small size of lithium frequently confers special properties on its compounds and for this reason the element is sometimes termed anomalous . For example, it is miscible with Na only above 380° and is immiscible with molten K, Rb and Cs, whereas all other pairs of alkali metals are miscible with each other in all proportions. (The ternary alloy containing 12% Na, 47% K and 41% Cs has the lowest known mp, —78°C, of any metallic system.) Li shows many similarities to Mg. This so-called diagonal relationship stems from the similarity in ionic size of the two elements / (Li ) 76pm, / (Mg ) 72pm, compared with / (Na ) 102pm. Thus, as first noted by Arfvedson in establishing lithium as a new element, LiOH and LiiCOs are much less soluble than the corresponding... 

Ternary alkali-metal halide oxides are known and have the expected structures. Thus Na3C10 and the yellow K3BrO have the aqti-perovskite structure (p. 963) whereas Na4Br20, Na4l20 and K4Br20 have the tetragonal anti-K2NiF4 structure. 

Lower formal oxidation states are stabilized, however, by M-M bonding in ternary chalcogenides such as M MeQn, M4M6Q13 (M = alkali metal M = Re, Tc Q = S, Se) and the recently reported M gMeS. Their structures are all based on the face-capped, octahedral MeXg cluster unit found in Chevrel phases (p. 1018) and in the dihalides of Mo and W... 

Whereas the electrochemical decomposition of propylene carbonate (PC) on graphite electrodes at potentials between 1 and 0.8 V vs. Li/Li was already reported in 1970 [140], it took about four years to find out that this reaction is accompanied by a partially reversible electrochemical intercalation of solvated lithium ions, Li (solv)y, into the graphite host [64], In general, the intercalation of Li (and other alkali-metal) ions from electrolytes with organic donor solvents into fairly crystalline graphitic carbons quite often yields solvated (ternary) lithiated graphites, Li r(solv)yC 1 (Fig. 8) [7,24,26,65,66,141-146],... 

G4, Z1). Sodium reacts to form C Na, although ternary systems with other alkali-metal compounds are known (A3, B6). 

The same reasoning may hold for the virtual absence of transition metal dicarbides with (C2) anions. On the other hand, stable multinary compounds in A-M-(BNx), AE-M-(BNx), or Ln-M-(BNx) systems can exist with an electron-rich transition metal (M), similar to the known ternary dicarbides AM(C2) with A=alkali and M = Pd, Pt [25]. In these cases the valence electrons provided from A or AE metals fill the bonding (BNx)" or (C2) levels, and the transition metal retains an approximate d ° configuration. 

Low-temperature solvents are not readily available for many refractory compounds and semiconductors of interest. Molten salt electrolysis is utilized in many instances, as for the synthesis and deposition of elemental materials such as Al, Si, and also a wide variety of binary and ternary compounds such as borides, carbides, silicides, phosphides, arsenides, and sulfides, and the semiconductors SiC, GaAs, and GaP and InP [16], A few available reports regarding the metal chalcogenides examined in this chapter will be addressed in the respective sections. Let us note here that halide fluxes provide a good reaction medium for the crystal growth of refractory compounds. A wide spectrum of alkali and alkaline earth halides provides... 

Sato et al. " measured the viscosities of some binary and ternary alkali carbonates. Since melt creep must be prevented, a highly sintered alumina crucible was used instead of a gold-plated nickel crucible. Homogeneity of a mixture sample was achieved by gas bubbling. A laser beam is combined with a computer-assisted time counter to obtain the logarithmic decrement. Roscoe s equationi3i has been used for calculation of the viscosity, while it has been claimed by Abe et al. that the viscosities calculated from Roscoe s equation are 0.6-1.5% lower than those from more rigorous equations. 

The ternary fluorides M2HgF4 (M = Rb, Cs), obtained by heating the alkali-metal fluorides MF with Hg2F2 under carefully controlled conditions, crystallize in the well-known K2NiF4 type, with octahedra sharing four corners to form layers lDC2[I IgF2F4/2]2 and the cations M+ embedded between these layers.350... 

The crystal lattices of a series of ternary alkali metal-silver acetylenediide [M Ag(C=C)] (M1 = Li 161, Na, K 162, Rb, Cs 163) have been analyzed by Ruschewitz and co-workers using X-ray powder diffraction.209 Neutron powder diffraction experiments have also been performed on 161-163 for obtaining precise bond lengths. It has been found that for 161 and 162, the [Ag(C C)] chains were packed parallel to each other, whereas for 163, they were aligned in layers that were rotated by 90° with respect to each other (see Figure 51). 

Figure 51 Ternary alkali metal—silver(i) acetylenediides.

Ternary acetylides of the composition M[M (C2)J, M = alkali metal, M = transition metal, are solid-state compounds, which depending upon their composition may exhibit either insulator or semi-conductor behavior. 

Bronger, W. and G. Auffermann, New ternary alkali-metal-transition-metal hydrides synthesized at high pressures Characterization and properties, Chem. Mater., 10, 2723,1998. 

Isolated octahedral M6(p3-Q)82+ (Q=S, Se) clusters are found in a big family of Tc and Re ternary sulfides and selenides of general formula AxM6Qn+ ) where A is an alkali, Tl+, Cu+ (x=4) alkaline earth, Eu2+ or Pb2+ (x=2) ion, and y = 0, 1 or 2. These phases were discovered and thoroughly studied by Prof. W. Bronger s group. The cluster units contain regular M6 octahedra with M-M bond lengths of 2.60-2.65 A for Tc and... 

Alkali metal compounds Li, Na, K, Rb, Cs All soluble Some complex (ternary) alkali metal salts... 

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