Beryllium complexes anionic

Beryllium complexes, 3, 3 acetylacetone solvolysis, 2, 378 amides, 2, 164 amines, 3, 7 anionic, 3, 10 1,3-diketones... 

Polyalcohols do not generally interact noticeably with beryllium, probably on account of the low acidity of the alkyl-OH group. Two exceptions are known where solid compounds have been isolated. The complex anion [bis(meso-oxolane-3,4-diolato)Be]2 has been shown to contain two anionic diolato ligands (258). 

Write the formulas for the following salts, by referring to Table 10-1 show the charges on the metal ion and on the complex anions sodium sulfate calcium silicate barium perchlorate beryllium carbonate aluminum nitrate aluminum sulfate aluminum phosphate potassium chlorate potassium sulfite. 

Eriochrome Cyanine R (ECR) (formula 4.17) reacts with beryllium ions [4,9,10,16,30] similarly to Chrome Azurol S (see Section 9.2.1). At pH 9.7, A-max of ECR is 435 nm and that of its water-soluble beryllium complex is 525 nm. The molar absorptivity of the complex is 1.5 10 . EDTA, tartrate and cyanide are used as the main masking agents for interfering metals. In the presence of cationic surfactants, the sensitivity is increased several times, and significant bathochromic shifts are observed. In the case of CTA, e = 8.7-1 O at 590 nm (pH 7) [31,32]. Beryllium was also sorbed on anion exchange resins impregnated with ECR [33]. 

Beryllium complexes, 3 amines, 7 anionic, 10 hydrates, 6 phthalocyanine, 59 poly carboxylic acid, 33 Schiff bases, 28 Beryllium dichloride ether complexes, 8 Beryllium difluoride ammine complexes, 7 Beryllium dihalides sulfide complexes, 10 Beryllium halides amine complexes, 8 ammonia complexes, 7 carbonyl complexes, 9 Beryllium nitrate basic, 32... 

It is shown that a solution of beryllium hydroxide in a solution of beryllium sulphate raises the freezing point of the latter and lowers its conductivity. The solutions obtained are not colloidal nor does the beryllium enter into a complex anion as is shown to be the case when a berylonate is present. 

Published equilibrium constants for monocarboxylato complexes are summarized in Table VII. All that can be deduced with certainty from these data is that the anions derived from monocarboxylic acids form rather weak complexes with beryllium. In all probability they act as monodentate ligands. The possibility of bidentate chelation using both carboxylate oxygen atoms can be ruled out on the grounds... 

The interaction of beryllium with nitrilotripropionic acid (H3ntp) has been investigated in some detail (244). This acid forms a strong complex (log Kt = 9.24) that can be isolated as a solid. The crystal structure of the anion [Be(ntp)] is shown in Fig. 23. The structure confirms the coordination of the nitrogen atom along with an oxygen atom from each carboxyl group. 

Other anionic complexes of beryllium that have been detected are (NH4)2Be(N03)4,141 (NH4)2Be(NCS)4-MeCN and (NH4)2Be(NCS)3-MeCN.142 ESCA studies on beryllium and magnesium complexes of the type [M(NCS)4]2 and [M(CNS)3L] (L = DMF, py, MeCN) are consistent with N-bonding thiocyanate anions being present.142 The structure of K[Be(NH2)3] shows the beryllium to be in a trigonal planar unit.143... 

Density functional theory studies arene chromium tricarbonyls, 5, 255 beryllium monocyclopentadienyls, 2, 75 chromium carbonyls, 5, 228 in computational chemistry, 1, 663 Cp-amido titanium complexes, 4, 464—465 diiron carbonyl complexes, 6, 222 manganese carbonyls, 5, 763 molybdenum hexacarbonyl, 5, 392 and multiconfiguration techniques, 1, 649 neutral, cationic, anionic chromium carbonyls, 5, 203-204 nickel rj2-alkene complexes, 8, 134—135 palladium NHC complexes, 8, 234 Deoxygenative coupling, carbonyls to olefins, 11, 40 (+)-4,5-Deoxyneodolabelline, via ring-closing diene metathesis, 11, 219... 

The addition of soluble carbonates to beryllium salt solutions gives only basic carbonates. Beryllium salt solutions also have the property of dissolving additional amounts of the oxide or hydroxide. This behavior is attributable to the formation of complex species with Be—OH—Be or Be—O—Be bridges. The rapidly established equilibria involved in the hydrolysis of the [Be(H20)4]2+ ion are very complicated and depend on the anion, the concentration, the temperature, and the pH. The main species, which will achieve four-coordination by additional water molecules, are considered to be Be2(OH)3+ and Be3(OH)3+ (probably cyclic). 

An operational description is that one reactant (the more ionic compound with the more electropositive metal) transfers alkyl anions to the other. Thus the four methyl groups in Li2BeMe4 form a distorted tetrahedron around the beryllium, with longer distances to the lithium ions. However, this description is oversimplified. The low-temperature nuclear magnetic resonance (NMR) spectrum of Li3MgMe5 has three different methyl resonances, suggesting structure (14), related to the MeLi tetramer. Ate complexes with zinc and aluminum compounds also form. Electron-deficient bridge-bonded structures, exemplified by the X-ray structure of... 

Hexaamminecobalt(III) carbonatoberyllates are generally insoluble in water, but complete precipitation of beryllium is obtained only in procedures A-1 and A-3. Although potassium oxohexacarbonatotetraberyllate dissolves in water to form a clear solution, a white flocculent precipitate separates after a few minutes, indicating that the complex carbonate anion must be unstable in aqueous solution. 

The next higher order of complexity consists of the so-called melasilicate anions, which are cyclic structures-" of general formula (SiOj) " occurring in benitoite, BaTiSi-,0,. catapleitc, Na2ZrSij0, H20. dioplasc, (Tuj.SihOix fiHjO. and beryl, Be,AI,Si,0. This is the mo.st important mineral source of beryllium, and also may form gem-quality stones (see Problem 16.9). 

Beryllium (Be, at. mass 9.012) forms cations Be ". In its chemical properties, beryllium resembles magnesium and aluminium. Beryllium hydroxide is precipitated at pH 6, and dissolves in alkali hydroxides. Freshly precipitated Be(OH)2 dissolves in NaaCOs solution to form a rather unstable carbonate complex. Beryllium also forms weak complexes with citrate, tartrate, and fluoride anions. Beryllium and its compounds are highly toxic. 

Beryllium, Ga, Al, Fe(III), and V(IV) interfere in the determination of In as a complex with ECR and CTA. The influence of Zr, Th and U is smaller. Anions complexing indium, viz. EDTA, citrate and tartrate, must be absent. This method for determining indium becomes highly selective when indium is first separated as the iodide complex (see Section 24.2.1). 

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