Thallium complexes alkoxides

The cubane structure [M4(m3-OR)4] (Fig. 4.6) is favoured by the alkali metal tertiary butoxides (M = K, Rb, Cs) and thallium(i) alkoxides, and also related species such as [Me4Zn4(/ t-OMe)4]. Another common tetranuclear structure [M4(jti-OR)6(OR)6] (Fig. 4.7) involves one central octahedral metal bridged to three tetrahedral metals in a chiral configuration (D3). Crystalline aluminium isopropoxide was the first example established to have this structural type. ° Interestingly in the heterometallic complex [ErAl3(OPr )i2] the central position is occupied by the erbium ion in a distorted trigonal prismatic configuration. ... 

Metal aUcoxide complexes with related alcohols are apparently edge-sharing bioctahedral dimers, on the evidence of the X-ray stmcture of the isopropyl complex. Some stable mixed alkoxides of the type Q[M3(OR)9] (Q = Li, Na, K, NH4, Ca/2) have been reported they distill in vacuo without decomposition. The X-ray stmctures of several bimetallic alkoxides obtained by Caulton,QZr2[0(/-Pr)]9,Q = Li[HO(i-Pr)], K(DME), Ba[0(i-Pr)], show a similar triangular stmcture with two 743 and three /r-OR bridges. The thallium salt of composition Tl2Zr((/R)6 obtained by the reaction shown in equation (18) has a distorted octahedral stmcture stabilized by six T1 F contacts. ... 

Mixed-metal alkoxide complexes of thallium are also known. For example, Sn(/u-t-BuO)3Tl has both Sn(II) and T1(I) ions." The thallium site is unreactive as a donor for metal carbonyls. However, as indicated earlier, the indium(I) site of the indium analogue shows Lewis-base character. The Sn(IV)/Tl(I) mixed alkoxide [Sn(EtO)eTl2] exists as a one-dimensional polymer. This adduct reacts quantitatively with SnCl2 to form the homoleptic, mixed-valent [Sn2(OEt)6]n. Thallium-titanium double alkoxides have been synthesized using thallium alkoxide as one of the starting materials. ... 

T.J. Boyle, C.A. Zechmann, T.M. Alam and M.A. Rodriguez, From clusters to ionic complexes Structurally characterized thallium titanium double alkoxides, Inorg. Chem., vol. 41, no. 4, pp. 946-957, 2002. 

Scheme 20.15). One equivalent of hydroxide or alkoxide is necessary to replace the halogen on the palladium complex I and the second equivalent is essential to form the borate II, so that the allq l group becomes more nucleophilic. According to Kishi and coworkers,the advantage of using thallium(i) hydroxide over sodium hydroxide is that the first can form insoluble thallium halide (TlX) which contributes to enhance this step and to accelerate the coupling. 

Oxidation of Metals by Oxygen Gas in Alcohol Media. This approach offers only extremely highly soluble and stable alkoxide complexes with rather high resistance to hydrolysis. It was first applied to the preparation of thallium(I) ethoxide, carried out in a Soxhlet filter ... 

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