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首页> 外文期刊>Polyhedron: The International Journal for Inorganic and Organometallic Chemistry >A new trend in metal-alkoxide chemistry: the elaboration of monophasic organic-inorganic hybrid materials
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A new trend in metal-alkoxide chemistry: the elaboration of monophasic organic-inorganic hybrid materials

机译：金属醇盐化学的新趋势：单相有机-无机杂化材料的制备

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The elaboration of monophasic organic inorganic hybrid materials is an important extension of metal alkoxide chemistry. These solids are obtained by hydrolytic polycondensation from a molecular precursor containing -Si(OR)(3) groups (at least two) covalently bound to an organic moiety. Using solid state C-13 NMR it is possible to demonstrate that, in all cases studied until now, the organic units are bound to the oxide matrix after hydrolysis. Si-29 permits the evaluation of the degree of polycondensation. All the solids obtained are kinetically controlled: their texture is highly dependent on all the parameters governing the kinetics of polycondensation (catalyst, temperature, solvent, concentrations, etc.). It is also possible to demonstrate that the geometry of the organic molecule is an important factor for both the texture and the short range organization of the solid. Weak interactions (charge transfer complexes) have been evidenced as possible controlling parameters for the solid formation. Short range organization in the hybrid material can be demonstrated using the easy polymerisation of bisacetylenic units which has been observed by heating the solid formed by hydrolytic polycondensation of [(MeO)(3)Si](2)C-4. The relationship between the porosity formed in the solid after elimination of the organic unit and the size of this unit was considered. A mild selective cleavage for Si-C bonds has been found and used for eliminating the organic moiety. After cleaving and recovering the organic molecule a monodispersed porosity is observed. However, there is no relation between the size of the pores and the size of the molecule. This fact is certainly due to a reorganization of the solid occurring during the Si-C bond cleavage. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 60]
机译：单相有机无机杂化材料的精制是金属醇盐化学的重要延伸。这些固体通过水解缩聚反应从含有共价键合到有机部分的-Si（OR）（3）（至少两个）基团的分子前体中获得。使用固态C-13 NMR可以证明，在迄今为止研究的所有情况下，水解后有机单元都与氧化物基质结合。 Si-29允许评估缩聚度。所获得的所有固体均受动力学控制：其质地高度依赖于控制缩聚动力学的所有参数（催化剂，温度，溶剂，浓度等）。也有可能证明有机分子的几何形状对于固体的质地和短程组织都是重要的因素。弱相互作用（电荷转移配合物）已被证明是固体形成的可能控制参数。杂化材料中的短程组织可以通过使用双炔属单元的简单聚合反应来证明，该反应通过加热[（MeO）（3）Si]（2）C-4的水解缩聚形成的固体而观察到。考虑了在除去有机单元之后固体中形成的孔隙率与该单元的尺寸之间的关系。已经发现对Si-C键的温和的选择性裂解，并用于消除有机部分。裂解并回收有机分子后，观察到单分散的孔隙率。但是，孔的大小和分子的大小之间没有关系。这个事实当然是由于在Si-C键断裂过程中发生的固体重组。 （C）1998 Elsevier ScienceLtd。保留所有权利。 [参考：60]

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