Bismuth alkoxide complexes

Bismuth alkoxide complexes are easily hydrolyzed and complex bismuth oxo-aUcoxide compounds may result as intermediates to full hydrolysis. A number of examples of these are known for the pentafluorophenox-ide system and include Bi4(/u.4-0)(/u.-0C6F5)6 /x3-0Bi(/x-0C6F5)3 2 2(C6H5CH3), Bi8(/r,4-0)2(M-3-0)2(M,-OC6F5)l6,... 

Monomeric arrangements are rare for alkoxide complexes of bismuth and require excess anionic ligands or bulky substituents. Otherwise the alkoxide ligands typically impose dimerization or multinuclear clustering, which are expressed in a variety of currently unusual structural arrangements (Table I). 

Another synthetic method to produce alkoxide complexes of bismuth employs the solvolysis of BiN(SiMe3)2 3 by alcohols. Bi(0CH2CH20Me)3 has been prepared in this fashion and is dimeric in the solid state.The similar complex with 0CMc2CH20Me is also known." These complexes are volatile and may be used for chemical... 

The bismuth aUcoxide was insoluble in methoxyethanol because of its own strong association however, it easily dissolved in methoxyethanol containing strontium alkoxide in Sr(OR)2 Bi(OR)3 molar ratios of >0.5 (Katayama and Sekine, 1991). As previously reported, the strong association of the bismuth alkoxide can be destroyed by the formation of a strontium-bismuth double alkoxide. The formation of the strontium-bismuth double alkoxide is discussed next. Also, the bismuth alkoxide was insoluble in strontium-tantalum or strontium-niobium double alkoxide solutions. The strontium-bismuth double alkoxide formed and then reacted with the tantalum or niobium alkoxide to prepare uniform alkoxide complex solutions (Kato et al., 1998). 

A variety of derivatives of bis-[Bi(tr)2X, X = Cl or N03], tris-(Bitr3), and tetra-([Bi(tr)4X][Na]) tropolonate complexes of bismuth (178, 179) have been prepared and spectroscopically characterized (176, 177, 180). Solid-state structures for examples of bis-(tropolonate) derivatives confirm the chelate interaction (171) and in the case of the nitrate derivative, reveal intermolecular alkoxide-bismuth [Bi-0 2.688 and 2.666 A] dimer contacts 52, which are slightly longer than the chelate bonds [Bi-0 2.130-2.323 A],... 

Analytical Data for Bismuth Hydroxy-, Alkoxide, and Ketothiolate Complexes... 

The complex formation of tungsten alkoxides with the alkoxides of other metals than the alkali, bismuth, and rhenium (see Section 12.21) has not been investigated in detail, and therefore the major attention below will be paid to the description of the bimetallic alkoxides of molybdenum. 

In very acidic solutions, bismuth(III) exists in the form of the nonaaquo ion [Bi(H20)9] +, which is similar to the aquo complexes of the lanthanide ions, but partial hydrolysis of bismuth(III) salts leads to the formation of bismuth oxo clusters. The core structure of these complexes is often based upon a Bie octahedral core with oxide, hydroxide, or alkoxide functions bridging the edges and/or faces of the octahedron. The [Bi6(OH)i2] + ion (11) has been studied spectroscopically. In oxo clusters, the octahedron is face-bridged by eight oxo or alkoxide functions (12). Such core structures have been found in the hydrolysis of bismuth nitrate or perchlorate. ... 

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