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Porous Coordination Polymers Based On Acylamide-Decorated Multidentate Carboxylate Ligands:Synthesis,Structures And Properties

Posted on:2012-05-24Degree:DoctorType:Dissertation
Country:ChinaCandidate:J G DuanFull Text:PDF
GTID:1261330425483564Subject:Inorganic Chemistry
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Recently, porous coordination polymers have attracted great attentions because of their intriguing topologies and potential properties in gas adsorption, catalysis, magnetism, optoelectronics and sensor. However, to screen and design the porous coordination polymers for high performance and to carry out the effective synthesis remains a great challenge.In this dissertation, we focused on the influence factors about the formaton of the coordination polymers and their potentional properties in gas storage, selective capture and sensor. This dissertation covers the following three parts:Firstly, we take systematical investigation in the influence of the metal ions related to the changed dimensionality of the complexes and the controllable shift degree of the pcu-type frameworks by changing temperature and modulator. Under the same conditions, three complexes (1-3) with different dimensionalities were obtained by the self-assemble of the acylamide-decorated ligands with transition metal ions. Interestingly, an unusual phenomenon has been observed that the dimensionality of these three coordination polymers gradually increases (1to3) with the decrease of coordination numbers of metal ions (7to4). Moreover, two pcu-type novel interpenetrated MOFs (4-5) with different pore sizes were obtained, and the shift degree of the interpenetrated frameworks was well controlled by employing a modulator and changing the reaction temperature. Their adsorption isotherms show that they have different porous distributions and improved H2uptake from1.6wt%(4) to1.9wt%(5). Secondly, we have obtained seven novel porous coordination polymers with acylamide-decorated tricarboxylate ligands and investigated the relationships between structures and potential properties. Solvothermal reaction afforded an agw-type porous coordination polymers (6). X-ray analysis shows that the overall structure was well packed by three types of polyhedra with densely decorated Lewis basic units that directly exposed to each individual cavity. The stimated apparent Brunauer-Emmett-Teller surface area (BET:~2690m2·g-1; Langmuir surface~3100m2·g-1) is very close to the theoretical value predicted by the geometric accessible surface area method (~2856m2·g-1). Moreover, complex6show higher selective capture of CO2/N2(25.1-60.8) and CO2/CH4(13.7-46.6), and higher uptake of CO2(22.12mmol·g-1,20KPa) at ambient temperature. Due to the strong CO2-framework interaction, their probe capacity to Lewis acid ions was expected. Complex7-9were obtained by the assemble of Ln(NO3)3and H3L3. The potential interactions of the acylamide group and Cu2+and Ag+decrease the antenna efficiency of the ligand in the f-f transition process from the Ln3+. Thus, the luminescence intensity of the Cu2+and Ag+-incorporated complex7decrease a lot, indicating the recognization to lewis acid metal ions.Thirdly, in2003, Yaghi reported the reticular systhesis, and several successful samples mainly derived from the single component ligand. However, the reticular systhesis with multi-component liagnds is still in their fancy. Herein, H3L3/H2BDC, H3L7H2NPDC and H3L3/H2BPDC were selected to construct the porous coordination polymers with Zn4O cluster, respectively (10-12). The obtained three porous coordination polymers have the same topology. Two kinds of channel were found along a axis and the sizes of the triquereous channel give a systemic change. Most importantly, the adsorption isotherms of CO2, CH4and H2indicate that the ion frameworks exhibit the porous character, eventhough the [(CH3)2NH2]+was found in the pores.All the work indicate that the introduction of functional acylamide group into the ligands has great influence in the formation of the porous coordination polymers and their related properties, especially, the recognization of CO2and some small Lewis acid metal ions. Therefore, it helps a lot to enrich crystal engineering for screening and designing the multi-functional porous coordination polymers with high performance.
Keywords/Search Tags:acylamide group, metal-organic framework, reaction factor, gas storage, selective capture, sensor
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