Several new mixed-metal analogues of MIL-53 have been synthesised using iron and vanadium. The properties of the mixed-metal materials are affected greatly by the ratio of the two metals. Analysis of the EXAFS spectra of a mixed-metal MIL-53(Fe, Cr) sample was performed supporting the homogeneity of the material. The investigation of mixed ironcobalt materials was also studied. Several new lanthanide-organic frameworks are described. Through mediation of the reaction solvent and subsequent calcinations, several new ytterbium-organic frameworks have been synthesised and their properties investigated. Using a solvent mixture of between 1:0 and 6:4 DMF to water leads to the formation of MB2, [Yb2(BDC)3(DMF)2]∙2H2O, which contains ytterbium-carboxylate chains. Calcination of MB2 creates Yb2(BDC)3, a material that exhibits permanent porosity. Further decreasing the DMF to water ratio in synthesis leads to the formation of MB3, [Yb2(BDC)3(DMF)2(H2O)2], which contains ytterbium-carboxylate dimers. Although sharing similar chemical formulae, MB2 and MB3 vary greatly in terms of structure and properties. Despite of this, both MB2 and MB3 can be calcined into the same Yb2(BDC)3 material, seen from the calcination of MB2. Attempts to create analogues of MB2 and MB3 using other lanthanides were unsuccessful with the exception of lutetium. In spite of this, doping of MB2(Yb) with other lanthanides was successful and their luminescence properties studies. Synthesis of isoreticular analogues of MB2 and MB3 were partially successful with an isoreticular analogue of MB3, MB5, being formed. Crystallisation of several metal-organic frameworks were followed using both ex situ and in situ methods and it was shown these two sets of techniques can complement one another to enable the pathways of MOF formation to be monitored.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:644918 |
| Date | January 2014 |
| Creators | Breeze, Matthew I. |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/67088/ |
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