TY - THES ID - 138608640 TI - Lab-in-a-crystal: a controlled nano-environment for manipulating molecules AU - Verheyden, Sofie AU - Ameloot, Rob AU - Roeffaers, Maarten. AU - KU Leuven. Faculteit Bio-ingenieurswetenschappen. Opleiding Master in de bio-ingenieurswetenschappen. Katalytische technologie (Leuven) PY - 2016 PB - Leuven KU Leuven. Faculteit Bio-ingenieurswetenschappen DB - UniCat UR - https://www.unicat.be/uniCat?func=search&query=sysid:138608640 AB - Nanoporous metal-organic frameworks (MOFs) are promising materials for molecular separations. In this thesis, the use of post-synthetic deprotection reactions was investigated to turn single MOF crystals into miniature devices for analytical applications. Such ‘lab-in-a-crystal’ (LIC) systems possess several potential advantages including high chromatographic resolution, short analysis time, low cost, usage of low amounts of sample, and low device footprint. In order to make LICs, photoactivatable MOF crystals were built out of ligands with nitrobenzyl photocleavable side groups. The bulky side groups were locally removed by UV irradiation (photodeprotection reaction) with a ultraviolet laser to create channels in the crystals accessible to guest molecules. Two different isoreticular frameworks with composition [Zn4O(Ligand)3] were made using solvothermal synthesis and the ligands: 2-((2-nitrobenzyl)oxy)terephthalic acid, 2,5-di((2-nitrobenzyl)oxy)tereph-thalic acid, and 2,2-di((2-nitrobenzyl)oxy)biph prepared with a mixture of both terephthalic acid derivatives and the second MOF was built out of the elongated biphenyl ligand. The MOF crystals were characterized using optical microscopy, NMR, XRD, TGA, and krypton physisorption. The mixed ligand MOF was “non-porous” since the penetration of guest molecules (ex. Acridine Yellow, Pyronin B) into the pores was hindered by the photocleavable groups. In the second MOF, the pore blockage was less effective but larger dyes (ex. Rhodamine 101) were efficiently excluded. The photolabile groups were locally removed using confocal and two-photon laser scanning microscopy to create respectively two- and three-dimensional channels in the MOFs. This was done under dehydrated conditions due to the high water sensitivity of the deprotected areas and the laser exposure was optimized to restrict photodamage. Remarkably, the mixed ligand MOF crystals were more sensitive to high-power irradiation than the extended MOF crystals. The transport of guest molecules inside the channels was investigated using dyes. The penetration of Pyronin B was studied extensively in experiments with the mixed ligand MOF. The dye interacts with the MOF scaffold and concentrates in the channels while being excluded from the non-deprotected areas. A similar effect was observed for Rhodamine 101 in the extended MOF channels. As a stepping stone on the path to LICs this thesis demonstrates that localized photodeprotection reactions can create well-defined porous channels in MOF single crystals for the analysis of molecules. ER -