Triphenylarsine oxide complexes

Phenyl, 4-methoxyphenyl, and 4-ethoxyphenyl tellurium thiocyanates are known only in the form of their complexes with thiourea1,2 ethylenethiourea3, triphenylarsine oxide, 3-methylpyridine, 3-methylpyridine /V-oxidc, or 4-methylpyridine Af-oxide2. These compounds were prepared from the diaryl ditellurium compounds, thiocyanogen, and the ligands2. 

Thorium is one of the few multivalent metals [others are Au(III), Ce(IV), U(VI), and Cr(VI)] which are extractable as nitrate complexes from nitric acid solutions [25-28]. The extractants used include TBP in CCI4 [26,29], TOPO in cyclohexane, toluene or xylene [25,30,31], and triphenylarsine oxide in CHCI3 [27]. Other reagents used for extraction of the nitrate complex of thorium include dibutyl dithiophosphate in various organic solvents [32], dibutyl sulphoxide in xylene [28], and bis(2-butoxyethyl) ether [33].The liquid anion-exchanger Aliquat 336 in xylene [34] and a solution of tertiary ammonium salt (Hyamine) in dichloroethane [35] have been also proposed for extraction of Th. The presence of Li, Na, or A1 nitrate improves the extraction of thorium. Sulphate, phosphate, and tartrate do not interfere, but fluoride must be masked, e.g., by aluminium. Thorium has been separated from U and Pu with the use of Alamine 336 and TOPO (in xylene or cyclohexane) [36]. 

The anionic uranium(VI)-Arsenazo III complex has been extracted from aqueous solution (pH 1-3) with CHCI3 in the presence of Zephiramine [72]. In another method U(VI) is extracted with triphenylarsine oxide in CHCI3, back-extracted with 5.5 M HCIO4 containing oxalic acid, and converted into the Arsenazo III complex (e = 7.3-10 ) [8]. 

The complex of Ti with H2O2 makes a basis of the determination of Ti in ilmenites [1] and minerals and alloys [2]. Extraction of the titanium salicylate complex with triphenylarsine oxide in CHCI3 preceded the spectrophotometric measurement [2]. 

Extraction with triphenylarsine oxide in CHCI3 followed by the reaction with Arsenazo III (after stripping of the analytes with 4 M HCl) makes a basis of the determination of Zr and Hf (and Ti) in minerals and alloys [1], Sequential liquid-liquid extraction and spectrophotometric determination of zirconium(IV) with calixarene hydroxamic acid and thiocyanate has been described [2]. Colorimetric determination of Zr and Hf with Xylenol Orange and a liquid-liquid extraction of thenoyltrifluoroacetone complexes using H2O-IBMK has been studied [3]. 

Treatment of anhydrous oxybis(triphenylbismuth) perchlorate with oxygen-donor bases results in the formation of pentacoordinate cationic complexes [73IC944]. Dimethyl sulfoxide, pyridine iV-oxide, triphenylphosphine oxide and triphenylarsine oxide are commonly employed ligands. 

The reaction between Bils and triphenylarsine oxide gave a complex, dinuclear product Bi2l6(Ph3AsO)3, in which each bismuth atom was in approximately octahedral co-ordination/ The first atom is attached to three terminal and three bridging iodine atoms (mean values 2.93 and 3.32 A), while the second is associated with the three bridging iodines and three oxygen atoms. 

Bromo(bispentafiuorophenyl)thallium reacts with the sodium or thallium(i) salts of the j8-diketones, (MeCO)gCH2, CFa-CO-CHa-COMe, (CF, CO)3-CH2,PhCOCHj-COMe,and (PhCO)sCH, to form four-co-ordinate dionato complexes, e.g. (C,F5)sTl[(MeCO),CH], and with the sodium salt of 8-hydroxyquinoline to form a dinuclear complex with bridging ligands. Reaction of these with triphenylphosphine oxide and triphenylarsine oxide, and with 2,2 -bipyridyl and phenanthrene, yields a number of five- and six-co-ordinate complexes. ... 

The triphenylarsine oxide-catechol complex has been shown to consist of a catechol molecule hydrogen-bonded to the oxygen of one arsine molecule through both OH groups." The O O contacts are 2.63 and 2.60 A. The two molecules suffer virtually no distortion in the formation of the complex. 

The rate with triphenylarsine oxide is fiurst-order with respect to both the iron(iv) complex and the base. The reaction mechanism is considered to involve the attack of the nucleophile on [Fe(mnt)3] (or on a half-bonded intermediate)... 

The iron atom in [Fe(mnt)3] is formally iron(iv). The study of the reaction of this complex with triphenylarsine oxide thus represents an investigation of substitution kinetics at a novel metal centre. The reaction is in fact both substitution and redox, with the available evidence not sufficiently ample to enable a firm mechanism to be proposed. ... 

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