Gallium complexes ethers

In addition to the above, a series of other molecular complexes are applied as precursors for obtaining chelates on the basis of N,0-donor ligands. Thus, gallium trichloride etherate was used (3.108) to synthesize the ICC of 2-a-hydroxybenzyl-benzimidazole [199] ... 

While the liquid-liquid extraction of inorganic elements as coordination complexes with thiocyanate ions can be traced back to Skey (1867), the extraction from hydrochloric acid into ether of iron(III) (J. W. Rothe, 1892) or gallium (E. H. Swift, 1924) depends on the formation of solvated acido complexes derived from HMC14 extractions of metal complexes from nitric, thio-cyanic, hydrofluoric, hydrochloric and hydrobromic acids were studied exhaustively by Bock and his collaborators (1942—1956).6... 

A solution of Li[GaH4] in diethyl ether is prepared by the standard methods,J1 and is stored in a needle-valve O-ring flask. The concentration of Li[GaH4]-ether solution is determined by hydrolysis of a known volume of the solution followed by gallium determination by ethylenediamine-tetraace-tic acid, disodium salt using copper-PAN [l-(2-pyridylazo)-2-naphthol copper complex] as the indicator.4 It is assumed that all the gallium is present as the tetrahydrogallate. Only an approximate concentration need be determined since an excess of sodium hydride or potassium hydride is used. 

The tendency of the aluminium atom to complete its electron octet is manifested as the Lewis acidity of organoaluminium compounds. This is demonstrated by the formation of 1 1 complexes of trialkylaluminium with anions or bases such as ethers and amines. Organoaluminium compounds are generally more acid than the organoderivatives of boron, indium and gallium. For steric reasons, complex formation is more difficult in compounds of... 

There are numerous examples of the extraction of macrocomponents as chloride complexes in the analysis of various materials. The extraction of iron(III) from hydrochloric acid medium, prior to determination of trace elements, has been thoroughly investigated [64]. Macroquantities of gallium were extracted from 6-7 M hydrochloric acid with di(2-chloroethyl) ether [65,66], and gold(III) was extracted with isoamyl acetate [67]. 

The gallium chloride complex, GaCU", reacts with Rhodamine B (formula 4.29), to form the ion pair which can be extracted from HCl medium into benzene or other solvents. The pink extract is the basis of a sensitive and selective method for the determination of gallium [20-22]. Addition of NaCI improves the extraction efficiency very effectively [22]. A mixture of benzene and diethyl ether, and also o-dichlorobenzene [23], have been recommended as extractants. Since Rhodamine B is only slightly soluble in o-dichlorobenzene, but dissolves readily in the meta-isomer, the o-dichlorobenzene must not be contaminated with the metaisomer. 

The indium iodide complex [1-3] is > 99% extracted into diethyl ether from 0.5-2.5 M HI (6-30%). Gallium is not extracted under these conditions, but it is extracted from 6 M HCl. The hydriodic acid can be replaced by 0.5-3 M H2SO4 containing 15-20% of Kl. Chloride, bromide, fluoride, phosphate, and citrate do not interfere in the extraction of In from iodide media. Under the optimum conditions for the extraction, Tl, Cd, and Sn (and some Bi, Zn, Hg, and Sb) are extracted. Aluminium and Fe(II), like Ga, are not extracted. The indium iodide complex has also been extracted into chloroform containing N-benzylaniline [4,5]. 

Bis[l,l -bi-2,2 -hydroxynaphth-3-ylmethyl] ether-gallium/lithiuni complex. 

Aluminum azide is obtained from reacting AICI3 with NaNs in THF, or from the reaction of A1H3-Et20 with HN3 in ether at low temperature. When trimethylamine adducts of alane are employed, solids thought to be azido complexes are produced (equation 7). Aluminium (and gallium) compounds X2M(N3), where X = Br or I, have been prepared by the reaction of MX3 with the halogen azide 7W3 in benzene. They are polymeric solids which show v(M—N3) modes near 490 cm" (M = Al), or 430 cm" (Ga) in the vibrational spectra. 

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