节点文献

过渡金属硼磷酸盐化合物的合成、结构与性质研究

Syntheses, Structures and Properties of Transition Metal Borophosphates

【作者】 杨玮婷

【导师】 于吉红; 徐如人;

【作者基本信息】 吉林大学 , 无机化学, 2010, 博士

【摘要】 本论文研究了开放骨架过渡金属硼磷酸盐化合物的合成、结构及相关性质。利用硼酸熔融法和水热法,合成了一系列具有新颖骨架结构的硼磷酸盐化合物,对其合成、结构及相应的性质进行了详细的研究。主要结果如下:?1.利用硼酸熔融法从H3BO3-V2O5-Na2HPO4·12H2O体系合成出了一个具有新颖三维开放骨架硼磷酸钒化合物Na2[VB3P2O12(OH)]·2.92H2O。该化合物包含多维交叉的8元环、12元环和16元环孔道,是首例含有笼状结构的硼磷酸盐化合物。2.利用硼酸熔融法从H3BO3-MnCl2·2H2O-H3PO4-NH2COCH3体系合成出了一个具有新颖开放骨架硼磷酸锰化合物(NH46[Mn3B6P9O36(OH)3]·4H2O。该化合物沿[001]方向具有一维12元环直孔道,自由孔径为7.105×7.138 A。硼磷酸阴离子部分结构含有新颖的B/P比为2/3的基本结构单元。磁性研究表明该化合物含有弱的铁磁性成分。3.以二乙烯三胺为模板剂,在水热条件下合成了一个新的具有B/P比为4/7和混合价态铁的层状硼磷酸盐化合物(C4N3H16)(C4N3H15)0.5[Fe2B4P7O26(OH)4]。该化合物中含有罕见的无机阴离子双层结构,双层内含有沿[100]方向的8元环孔道。这个平行于ab面的无机双层彼此之间通过氢键连接构成三维的超分子骨架,含有拟10元环孔道。磁性研究表明该化合物在温度低于9.6 K时呈现亚铁磁性行为,2.0 K时的矫顽场和剩磁分别为2440 Oe和0.17μB。4.以1,2-丙二胺和哌嗪为模板剂,在水热条件下合成了三个同构的含有机模板剂的过渡金属硼磷酸盐(C3H12N2)[MnB2P3O12(OH)]、(C3H12N2)[FeB2P3O12(OH)]和(C4N2H12)[FeB2P3O12(OH)]。该系列同构化合物的骨架具有沿[011]、[011]和[100]方向的8元环、8元环和9元环三维交叉孔道。这些化合物的合成表明在合适的条件下1,2-丙二胺与哌嗪具有类似的模板能力,能够导向相同的骨架结构,但是对骨架的对称性和孔道形状有影响。

【Abstract】 Inorganic microporous material constitutes a very important area of the materials science. The structure and composition of the inorganic framework have been widely developed in the past. Borophosphate, as a new branch of inorganic materials, has shown fascinating structural diversities and potential applications in optical, magnetic, catalytic and ion-exchanged aspects.At the early stage of the study of borophophates, most compounds were obtained by using high temperature solid state syntheses. Since in 1990s, the hydrothermal method was introduced into the syntheses of borophosphates, the verities and quantities have grown rapidly. Recently, boric acid flux method was developed, and some new boron-contained compounds were successfully prepared.In this thesis, boric acid flux and hydrothermal synthesis method were employed to synthesize the transition metal borophosphates. Several new borophosphates are obtained, and the synthsis conditions are investigated. In additional, the properties of the synthesized compounds are studied in detail.Among the metal borophosphate compounds, vanadium borophosphates with rich anionic structures, especially the clusters, have been reported. A new three-dimensional (3-D) open-framework vanadium (IV) borophosphate, Na2[VB3P2O12(OH)]·2.92H2O (VBPO-CJ27), has been synthesized by using boric acid flux method. Single-crystal structure analysis reveals that its structure is constructed by the connection of VO6 octahedra, PO4 and BO4 tetrahedra, and BO2(OH) trigonal planes to form 3-D anionic framework containing intersecting 8-, 12- and 16-ring channels. Charge neutrality is achieved by Na+ ions, and the guest water molecules locate in the void space of the open framework. To the best of our knowledge, it is the first borophosphate with extra-large 16-ring openings. Interestingly, its structure features unprecedented 128166 super cavities. The magnetic measurement reveals that VBPO-CJ27 is paramagnetic. Ion-exchange studies show that Na+ ions can be partially exchanged by NH4+ ions.Most of the synthesized microporous borophosphates possess small pore openings, which restrict its applications as porous materials. A new three-dimensional (3-D) open-framework manganese borophosphate, (NH46[Mn3B6P9O36(OH)3]·4H2O (MnBPO-CJ31), has been synthesized by using boric acid flux method. Single-crystal structure analysis reveals that its anionic framework structure is constructed by the connection of MnO6 octahedra, BO4, PO4 and PO3(OH) tetrahedra containing 12-ring straight channels along the [001] direction with the large free aperture of 7.105×7.138 A. Charge neutrality is achieved by NH4+ ions, and the guest water molecules locate in the void space of the open framework. To the best of our knowledge, it is the first borophosphate compound, which features 3-D anionic partial structure with B/P ratio of 2/3 containing a new type of fundamental building unit (FBU). Magnetic study reveals the existence of ferromagnetic component in MnBPO-CJ31.In order to better understand the borophosphate chemistry, the polyhedra of metal atoms are usually disregarded and mainly the anionic partial structures of borophosphates will be focused on. The known borophosphate anionic frameworks can be derived from a few typical borophosphate fundamental building units with rich B/P ratios. A new layered iron borophosphate, (C4N3H16)(C4N3H15)0.5[Fe2B4P7O26(OH)4] (FeBPO-CJ28), with a novel B/P ratio of 4/7 and mixed-valent iron (II, III) was prepared under mild hydrothermal conditions in the presence of diethylenetriamine (DETA) as the template. Single-crystal analyses indicate that the structure comprises unprecedented anionic double layers [Fe2B4P7O26(OH)4]4- with one-dimensional 8-ring channels along the [110] direction, which are made up of FeO6, BO4, PO4 and HPO4 polyhedral units. Such double layers parallel to ab plane are connected by inter-layer hydrogen bonds forming the three-dimensional (3D) supramolecular open framework with pseudo 10-ring channels along the [110] direction. Protonated DETA cations locate in the 8-ring channels and pseudo 10-ring channels to compensate the negative charge of the anionic framework. The borophosphate anionic structure is featured by a new eleven-mer fundamental building unit (FBU) [B4P7O26(OH)4]. The magnetic measurement reveals that FeBPO-CJ28 exhibits ferrimagnetic behavior below 10 K with a hysteresis loop at 2 K (HC = 2440 Oe, MR = 0.17μB).Organo-templated syntheses of borophosphates have attracted more and more attentions in recent years. It is found that one organic template can direct multiple different frameworks under different gel conditions. On the other hand, multiple different organic templates can also produce the same framework under suitable conditions. However, such multiple-template-one-structure phenomenon is rarely observed in the syntheses of borophosphates. Three new isostructural organo-templated transition metal borophosphates, (C3H12N2)[MnB2P3O12(OH)] (MnBPO-CJ30), (C3H12N2)[FeB2P3O12(OH)] (FeBPO-CJ30A) and (C4H12N2)[FeB2P3O12(OH)] (FeBPO-CJ30B) were hydrothermally synthesized by using 1,2-diaminopropane and piperazine as the template, respectively. Single-crystal X-ray diffraction analyses reveal that the framework of MBPO-CJ30 (M = Mn, Fe) is constructed from the connection of infinite loop branched borophosphate 1[B2P3O12(OH)4-] chains and MO6 octahedra, giving rise to three-dimensional (3-D) intersecting 8-, 8- and 9-ring channels along the [011], [011] and [100] directions, respectively. The negative charge of the framework is compensated by the diprotonated 1,2-diaminopropane or piperazine cations located in the 9-ring channels. Structural analyses reveal that the organic amines that have the similar structure-directing ability but differing in size and shape have an influence on the crystal symmetry as well as the pore shapes of the 9-ring channels of these isostructures. Magnetic studies reveal that MnBPO-CJ30 exhibits antiferromagnetic behavior with weak ferromagnetic component to the magnetic interactions.The syntheses of borophosphates in this work reveals that more borophosphate compounds with novel structures, as well as interesting physical properties, will be further explored, and would be good candidates for new functional materials.

  • 【网络出版投稿人】 吉林大学
  • 【网络出版年期】2010年 09期
节点文献中: 

本文链接的文献网络图示:

本文的引文网络