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The preparations, stabilities and structures of the complexes R2TlX and R2 LTlX (R = C6F5, p-HC6F4, or o-HC6F4; X = Br or Cl; L = Ph3PO, 2,2′-bipyridyl (bpy) or Ph3P) have been examined or (R = C6 F5) reinvestigated. The derivatives R2TlX are monomeric in acetone, from which the complex (p-HC6F4)2 Me2COTIBr has been isolated. In this solvent, the complexes R2LTlX (L = Ph3PO, bpy, or Ph3P) undergo partial dissociation by loss of L. When L = bpy, there is also slight ionization into R2LTl+ and R2TlX?2. The acceptor properties of R2TlX compounds towards uncharged ligands decrease R = C6F5 ? p-HC6F4 > o-HC6F4 > Ph. Dimeric behaviour is observed for R2TIX compounds in benzene, whilst R2LTlX (L = Ph3PO or bpy) derivatives show slight but significant association. In the solid state, R2TlX compounds are considered to be polymeric with five coordinate thallium, and R2LTlX derivatives to be dimeric with five (L = Ph3PO) or six (L = bpy) coordinate thallium by contrast with four coordinate dimeric and four or five coordinate monomeric structures previously proposed for the respective pentafluorophenyl derivatives. Halogen bridging is unsymmetrical for R = C6F5 or p-HC6F4, but may be more symmetrical for R = o-HC6F4 when L = Ph3PO or bpy. Reported structural data for the complexes (C6F5)LTlX (L = Ph3AsO, Ph3P, Ph3As, or 1,10-phenanthroline; X = Br or Cl) and (C6F5)2TlCl?2 are reinterpreted and the proposed structures revised. 相似文献
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A novel method is developed for the extraction separation of thallium(III) from salicylate medium with n-octylaniline dissolved in toluene as an extractant. The optimum conditions have been determined by making a critical study of weak acid concentration, extractant concentration, period of equilibration and effect of solvent on the equilibria. The thallium (III) from the pregnant organic phase is stripped with acetate buffer solution (pH 4.7) and determined complexometrically with EDTA. The method affords the sequential separation of thallium(III) from thallium(I) and also commonly associated metal ions such as Al(III), Ga(III), In(III), Fe(III), Bi(III), Sb(III) and Pb(II). It is used for analysis of synthetic mixtures of associated metal ions and alloys. The method is highly selective, simple and reproducible. The reaction takes place at room temperature and requires 15-20 min for extraction and determination of thallium(III). 相似文献
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Shigeaki Numata Hideo Kurosawa Rokuro Okawara 《Journal of organometallic chemistry》1974,70(2):C21-C23
Some trimethylsilylmethyl derivatives of thallium(III) have higher stability and unusual coordination behavior in comparison with simple alkylthallim(III) analogs for steric reasons. 相似文献
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Anna N. Gidd Madhukar D. Bhand Gavisiddappa S. Gokavi 《Transition Metal Chemistry》1995,20(4):367-368
Summary The complementary reaction between TlI and AuCl
inf4
sup–
was studied in a 3.0 mol dm–3 HCl medium. The active species of oxidant and reductant were found to be HAuCl4 and TlCl
inf2
sup–
, respectively. A mechanism involving these reactive species is proposed, in agreement with the results obtained. 相似文献
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The reaction of TlCl3 with RLi leads to complexes of the general formula TlR2Cl (R = C6F5, p-C6F4H, m-C6F4H, 2,4,6-C6F3H2, p-C6FH4 or m-CF3C6H4). Some of these undergo oxidative addition reactions with gold(I) complexes to give polyfluorophenyl derivatives of the types AuR2ClL and Au(C6F5)R2(tht) (tht = tetrahydrothiophen), and with SnCl2 to give oily materials from which stable solids of the general formula Q[SnR2Cl3] can be isolated by addition of QCl (Q = Et4N or Ph3BzP). 相似文献
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Toyo Kaiya Naohiro Shirai Jinsaku Sakakibara Yoichi Iitaka 《Tetrahedron letters》1979,20(44):4297-4298
Reaction of grayanotoxin-II (1) with thallium nitrate gave 3(S), 20-epoxy-6 (S), 14 (R), 16 (R)-trihydroxy-5-oxo-5, 10-seco-ent-kaur-1 (10) -ene (2). The structure of 2 was elucidated by the X-ray diffraction analysis of its reduction product (3). 相似文献
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We have obtained 2,7-dimethoxy-2,7-dimethyl-3,5-octadiene by the action of thallium(III) nitrate on trans-allo-ocimene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1087–1089, May, 1990. 相似文献
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Reaction of nerol () with thallium(III) perchlorate gave 6-oxabicyclo[3.2.1]octane derivatives () and (), and 6,9-dioxabicyclo[3.3.1]nonane derivatives () as the cyclization products. 相似文献
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Yazdan Parast MS Morsali A Ebrahimpour P 《Dalton transactions (Cambridge, England : 2003)》2012,41(19):5848-5853
Four new thallium(I) coordination polymers, [TlBt](n) (1) (Hbt = 5-phenyltetrazole), [TlBbt] (2) (Hbbt = 5-(4-bromobenzyl)tetrazole), [Tl(2)Bdt](n) (3) (H(2)bdt = 5,5'-benzene-1,4-diylbistetrazole), [Tl(2)Pht·H(2)O](n) and [TlBet] (4), (Hbet = 5-(benzyl)tetrazole) have been synthesized and characterized. The single-crystal X-ray data shows that, in compounds 1-3, the coordination sphere of the Tl(I) ion is the same and it is surrounded with six tetrazolate rings. In compound 4, one thallium atom has three interactions with tetrazolate groups and close Tl(I)···π (aromatic) contacts with the phenyl ring. Furthermore, in all cases the single-crystal X-ray data show the same stereo-chemical activity of the valence shell electron lone pair of Tl(I). There is a strong Tl(I)···Tl(I) interaction in one dimension in compounds 1 and 3. All these four compounds have been used as new precursors for the preparation of thallium(III) oxide nano-particles through a simple calcination method. Thallium(III) oxide was characterized by powder XRD diffraction and the morphology of nano particles characterized by scanning electron microscope (SEM). 相似文献
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The reaction between thallium(III) and oxalic acid in sulphuric acid medium has been investigated. Spectrophotometric results show that thallium(III) can be quantitatively reduced to thallium(I) with oxalic acid in aqueous medium when heated to near boiling point. Conditions for the estimation of the excess of oxalic acid with cerium(IV) sulphate in the presence of thallium(I) and for the estimation of a mixture of thallium(I) and thallium(III) have been investigated. The method is simpler than many other redox methods reported for the determination of thallium(III) and is free from many interferences encountered in these titrations. The reagents are cheap and quite stable. 相似文献
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Pier Giuseppe Ciattini Enrico Morera Giorgio Ortar 《Journal of heterocyclic chemistry》1982,19(2):395-400
Treatment of 4-chromanones 1a-g with thallium(III) nitrate in acidic methanol results mainly in dehydrogenation, whereas α-methoxylation and/or Taylor-McKillop rearrangement predominate in trimethyl orthoformate. The mechanistic features of these oxidations are briefly discussed. 相似文献
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A convenient method for determination of thallium(III) is based on photochemical reduction with hydrogen peroxide in the presence of bromide as catalyst, followed by oxidation of thallium(I) with potassium bromate. 相似文献
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Aromatic 1,2-bisamides undergo thallium (III) promoted oxidative intramolecular cyclization to generate new 5-membered heterocyclic rings. Formation of -quinone was shown to be a minor pathway in one case. 相似文献