Synthesis And Characterization Of Layered And Microporous Aluminophosphates

In recent years, molecular engineering of materials is in the stage of exploration, whose goal is to design materials with functionality in the level of molecular according to the relationship of structure and property. It is still a challenge task to rationalize the design and synthesis of microporous materials. Aluminophosphates constitute an important class of materials in the field of zeolites. Much more attensions have been paid on the design and synthesis of aluminophosphates with novel structures and favourable properties because of their potential application in catalysis, separation, and adsorption and host-guest assemblies. The diverse arrangement of AlO4, AlO5 and AlO6 polyhedral units and P(Ob)n(Ot)4-n polyhedral units (b: bridging, t: terminal, n = 1, 2, 3, 4) results in their fascinating structural architectures with 0-D clusters, 1-D chains, 2-D layers, and 3-D open-frameworks and diverse stoichiometries with different Al/P ratios. In the last decades, our molecular engineering group has synthesized a variety of aluminophosphates with diverse dimensions and stoichiometries by using hydrothermal or solvothermal technique, which extremely enrich the stucture database and synthesis database of aluminophosphates, and supply theoretical foundation for the rational design and synthesis of aluminophosphates with special structures. However, we still need to synthesize more aluminophosphates with novel structures in order to study the relationship between synthesis and sructure. In this thesis, we try to synthesize aluminophosphates with various structural dimensionalities and stoichiometries by using hydrothermal and solvothermal techniques. On the base of it, we futher study the relationship between synthesis and structure, and summarize some synthetic rules for rational design and sythesis of target materials. We synthesize a new 3D nickel aluminophosphate [C6N4H20]2[Ni(Al3P4O16)2] (NiAPO-CJ18) from hydrothermal system. Its structure is built up from the 2D Al3P4O163-layers with 4.6-net pillared by [Ni(TETA)2]6+ complexes formed under hydrothermal conditions, which contains intersecting 16-MR and 12-MR channels along the [100] and [001] direction, respectively. Two diprotonated TETA molecules coordinated to one Ni atom in bidenated fashion reside in the channels and form extensive H-bonds with the inorganic host. The structure character of NiAPO-CJ18 further suggests that 3D metal aluminophosphate open-framework can be assembled from a lower dimensional network through metal species. Templated by nickel complex Ni(C4N3H13)(C4N3H14)H2O formed under hydrothermal conditions, we synthesize a new layered aluminophosphate [Ni(C4N3H13)(C4N3H14)H2O][Al3P4O16] (AlPO-CJ17) with an Al/P ratio of 3/4. It contains 4.6.8-net macroanionic sheets featured by capped 6-MRs stacked in an ABAB sequence. Protonated nickel complex cations residing in two adjacent layers form complex H-bonds to the inorganic networks and stabilize the whole structure.With incorporation of Zn( Ⅱ), we synthesize a new aluminophosphate [Ni(C4N3H13)2][Zn2Al4P6O24] (ZnAPO-Ni) with CHA structure. nickel complex [Ni(deta)2]2+ formed under hydrothermal conditions as the structure-directing agent directs the formation of this structure. With incorporation of Co( Ⅱ), we synthesize a new aluminophosphate [C6N4H21]4[Co3Al6(PO4)12]·17H2O (CoAPO) by using triethylenetetraamine as a structure-directing agent. Its 3D anionic framework consists of strict alternation of PO3(=O) and TO4/AlO4 tetrahedra to form a cage with 12-MR cavity related to the sodalite cage. Protonated N,N-di(2-aminoethyl)ethylenediamine cations decomposed from triethylenetetraamine locate inside the channels and interact with the framework through H-bonds. On the base of experiments, we further study the influence of ethyleneamine, diethylenetriamine and triethylenetetraamine on the coordination modes of nickel cations and structures of the final products. The results show that nature of organic amine, and initial pH value and gel composition may be the key factors for the different coordination fashions in the final products. By using N-(2-aminoethyl)-piperazine (AEPP) as the template, we synthesize a new layered aluminophosphate [C6N3H17][Al2(HPO4)(PO4)2] (AlPO-CJ21) in an alcoholic system. Its inorganic layer containing a series of bridged-6 membered rings (MRs) is a new type of 4.6-net sheet built up from AlO4, PO2(OH)(=O) and PO3(=O) tetrahedra. Interestingly, inorganic helical chains of right-or left-handness are presented in the aluminophosphate layers, and fascinating hydrogen-bonded helices are self-assembled under solvothermal conditions between organic templates and inorganic sheets via strong H-bondings of O···N atoms. In the system of Al(iPrO)3—Ni(OAc)2·4H2O—H3PO4—DETA—H2O, we synthesize a 3D aluminophosphate [C4N3H16][Al4P5O22H4] (AlPO-1) with an Al/P...