Compounds with Complex Anions

Potassium Hexanitrocobaltate(III). Add a little acetic acid and an excess of potassium nitrite to a cobalt(II) salt solution. Heat the mixture. What gas evolves What precipitates Write the equation of the reaction. What is the coordination number of cobalt in this compound  

What is the composition of iron, cobalt, and nickel carbonyls Consider the structure of the carbonyls of these elements from the standpoint of the valence bond theory. 

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Compounds with Complex Cations (244). Compounds with Complex Anions (245). 

Electrocrystallization with the Ag(SCN)2 anion in various solvents always produced - in contrast to Cu(NCS) - a compound with complex anion stoichiometry (ET)Ag (SCN) (x - KS)." " ... 

Copper(I) forms compounds with the anions of both strong and weak acids. Many of these compounds are stable and insoluble in water. Compounds and complexes of copper(I) are almost colorless because the inner >d orbital of the copper is completely filled. There is a very strong tendency for copper(I) to disproportionate in aqueous solutions into copper(Il) and metallic copper. 

Compounds with complex alkynylgold anions [RC=CAuX] 258... 

ESR of, 16 117 IR spectrum of, 16 117 NMR spectrum of, 16 117 peroxide derivatives of, 16 125-127, see also specific compounds preparation of, 16 115-118 properties of, 16 115-118 Raman spectra of, 16 117 reactions of, 16 118-125 with carbonyls and carbonates, 16 124 with complex anions, 16 125 with halogen-containing compounds, 16 121-123... 

Antimony pentachloride, SbCh, is a liquid (mp 4°C, bp 140 °C dec ), which can be obtained by reaction of SbCls with elemental chlorine. Sohd SbCls exists in two modifications above 54.1 °C, it is trigonal bipyramidal, below this temperature, it changes reversibly into a double chlorine-bridged dimer. SbCls decomposes at 140 °C with formation of SbCls and CI2. It is a Lewis acid with a strong tendency to interact with a ligand (L) to give octahedral complexes LSbCls. Reactions with chloride ion donors lead to ionic compounds with SbCle" anions and unusual cations. Examples are shown in equations (10) and (11). 

Thiatriazinium salts 2, 4 and 6 are stable compounds, extremely sensitive to moisture. In general, the most stable salts arc obtained in the form of ion pairs with complex anions. 1-Halo-substituted thiatriazines 3 and 526 or thiatriazinyl radicals or their precursors,49,61 67,68 e.g. dimer 1, can be converted into the corresponding thiatriazinium salts. 

As compounds of coordinatively unsaturated trivalent aluminum, the organoaluminum compounds are Lewis acids and will combine with Lewis bases to form molecular compounds or complex anions. 

Silver-Metal Bonded Compounds. Stable salts of formula Me4N[Ag M(CO)3-Cp 2] (M = Mo or W) have been isolated from aqueous diglyme solutions of Na[M(CO)3Cp] and AgN03. Since their i.r. spectra are similar to those of the known Hg[M(CO)3Cp]2 compounds, the complex anions are believed to be non-centrosymmetric, with the first reported cases of linear M— Ag—M bonding. 

The real solution contains not one but I cations and not one but / anions. For this reason the total concentration of the cation M, in its complex compounds with all anion looks like as follows... 

Figure 7 Examples for polyanlonic valence compounds with an anionic tetrahedron complex where each tetrahedron extends one A - A bond to another tetrahedron.

Structural features which can not be predicted with valence ekstron rules. The valence elctron rules allow the prediction of a probable base tetrahedron for a compound with an anionic tetrahedron complex, however not the details how this base tetrahedron is linked with itself. In addition, instead of an expected single base tetrahedron there may occur two different base tetrahedra but with the restriction that the average of their codes, calculated with (28), corresponds to the classification code of the compound. 

The specific combination of ions in a coordination compound is the key to writing its formula and name. A coordination compound can consist of a complex cation with simple anionic counter ions, a complex anion with simple cationic counter ions, or even a complex cation with complex anion as counter ion. 

The base a,a -dipyridyl (a,a -dip) produces an intense red color in acid or neutral solutions of ferrous salts. The color is due to the formation of the stable complex cation [Fe(a,a -dip)3]+ (see page 263). This cation can combine with anions that have a large atomic volume to give slightly soluble, red crystalline compounds. Accordingly, complex anions, such as [Hgl4] , [CdIJ, [Ni(CN)J , etc. in particular, and likewise considerable quantities of iodides, serve as precipitants for [Fe(a,a -dip)8]+ ions. 

See the general references in the Introduction, and some more-speciahzed books [4, 6-58], Some articles in journals discuss actinide complexation and thermodynamics at elevated temperatures [59] classifying lanthanoids by multivariate analysis, albeit with results that seem hard to defend [60] designing sequestering agents for Pu and other actinoids [61] lanthanoid compounds with complex inorganic anions, part of a thematic issue on lanthanoid chemistry [62] Pm, discovery and chemistiy [63] recent Sc chemistiy [64] actinoid complexes [65] the transuranium elements [66] actinoid complexes with OH and [67] coordination numbers [68] the aqueous chemistiy and thermodynamics of Eu [69] photooxidation-reduction of Np and Pu [70] review of Pm [71] Rth thermochemistiy [72] unusual oxidation states of Ln and An [73] and Rth chemistiy [74]. 

Ionic Material. The kinetics of sorption-desorption processes of the ionic compound with the solid substrates under a variety of environmental conditions should be determined to arrive at the equilibrium concentration of the ionic compound in the free form. Complex/chelate formation of the ionic compound with the anions (organic and inorganic), micro-, and macrosolutes should be investigated to determine the extent of alteration in speciation and their behavior in water. Chelate formation with ligands containing donor atoms such as N, S, and Se, or even Cl in some cases (HgCl2) can modify the hydrophilic ionic compound into a strong lipid-soluble covalent compound. 

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