Department of Chemistry, CICECO, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Av. da República, Estação Agronómica Nacional, 2780-157 Oeiras, Portugal and Escola Superior de Tecnologia, Instituto Politécnico de Setúbal, 2910-761 Setúbal, Portugal.
Dalton Trans. 2013 Jun 21;42(23):8231-8240. doi: 10.1039/c3dt50132a. Epub 2013 Apr 16.
A Zn-Al layered double hydroxide (LDH) intercalated by Mo(η(3)-C3H5)Cl(CO)2(bpdc) anions (bpdc = 2,2'-bipyridine-5,5'-dicarboxylate) has been prepared by coprecipitation from aqueous solution and characterised by various techniques. The one-pot method gives rise to a highly organised intercalate with an interlayer spacing of 18.3 Å and up to six (00l) basal reflections in the powder X-ray diffraction pattern. Spectroscopic studies (FT-IR, FT-Raman, (13)C CP MAS NMR and UV-Vis) confirm the presence of structurally intact Mo(η(3)-C3H5)Cl(CO)2(bpdc) anions. The interlayer spacing of 18.3 Å indicates that the material contains a monolayer of guest anions positioned in such a way that the bpdc ligands are arranged with their longest dimension roughly perpendicular to the hydroxide layers of the host. Thermal properties were studied by thermogravimetric analysis and differential scanning calorimetry. The intracrystalline reactivity of intercalated dicarbonyl complexes was probed by using the hybrid nanocomposite as a precatalyst in the liquid phase epoxidation of cis-cyclooctene with tert-butylhydroperoxide as oxidant. Under the reaction conditions used, oxidative decarbonylation of the guest molecules takes place (with release of CO and CO2 as confirmed by on-line gas chromatography experiments) to give intercalated molybdenum oxide/bipyridine species that selectively catalyse the epoxidation reaction. The intracrystalline oxidative decarbonylation reaction is topotactic in nature.
一种 Zn-Al 层状双氢氧化物（LDH）被 [Mo(η(3)-C3H5)Cl(CO)2(bpdc)]（2-）阴离子插层（bpdc = 2,2'-联吡啶-5,5'-二羧酸根），通过水相共沉淀法制备，并通过各种技术进行了表征。一锅法得到了一种高度有序的插层物，具有 18.3 Å 的层间距和多达六个（00l）的粉末 X 射线衍射图案中的基面反射。光谱研究（FT-IR、FT-Raman、(13)C CP MAS NMR 和 UV-Vis）证实了结构完整的 [Mo(η(3)-C3H5)Cl(CO)2(bpdc)]（2-）阴离子的存在。18.3 Å 的层间距表明该材料含有一层位于其中的客体阴离子，其方式使得 bpdc 配体大致垂直于主体的氢氧化物层排列。通过热重分析和差示扫描量热法研究了热性能。通过使用杂化纳米复合材料作为预催化剂，在以叔丁基过氧化氢为氧化剂的顺式环辛烯的液相环氧化反应中，研究了插层二羰基配合物的晶内反应性。在使用的反应条件下，客体分子发生氧化脱羰（通过在线气相色谱实验证实释放出 CO 和 CO2），生成插层钼氧化物/联吡啶物种，它们选择性地催化环氧化反应。晶内氧化脱羰反应具有拓扑位错性质。
