Papers by Angiolina Comotti
Journal of Materials Chemistry A, 2020
Flexible aryl rings in fluorinated Fe-MOFs point C–F dipoles towards the corner of triangular cha... more Flexible aryl rings in fluorinated Fe-MOFs point C–F dipoles towards the corner of triangular channels capturing efficiently CO2 molecules.
Chemical Communications, 2019
Hyperpolarized 129Xe NMR highlights open porosity of fluorinated organic frameworks which show CO... more Hyperpolarized 129Xe NMR highlights open porosity of fluorinated organic frameworks which show CO2 and CH4 capture with high selectivity towards N2.
Natural radioactive gases and anthropogenic radionuclides such as radon, xenon, hydrogen and kryp... more Natural radioactive gases and anthropogenic radionuclides such as radon, xenon, hydrogen and krypton isotopes, need to be carefully monitored to be properly managed as pathogenic agents, radioactive diagnostic agents or indicators of nuclear activity. State-of-the-art gas detectors based on liquid scintillators suffer from many drawbacks such as lengthy sample preparation procedures and limited solubility of gaseous radionuclides, which produces a detrimental effect on measurement sensitivity. A potential breakthrough solution to this problem is using solid porous scintillators that act as gas concentrators and, therefore, could increase detection sensitivity. Highly porous scintillating metal-organic frameworks (MOFs) stand out as relevant materials for the realization of these devices. We demonstrate the capability of porous hafnium-based MOF nanocrystals exploiting dicarboxy-9,10-diphenylanthracene (DPA) as a scintillating conjugated ligand to detect gas radionuclides. The nanocr...
Angewandte Chemie International Edition in English, 1993
Acta Crystallographica Section A Foundations and Advances, 2021
Rotors, motors and switches in the solid state find a favorable playground in porous materials, s... more Rotors, motors and switches in the solid state find a favorable playground in porous materials, such as Metal Organic Frameworks (MOFs), thanks to their large free volume, which allows for fast dynamics. We fabricated MOFs with reorientable linkers and benchmark mobility also at very low temperature, to reduce the energy demand for motion-activation and light stimulus-response.
Nature Communications
Large Stokes shift fast emitters show a negligible reabsorption of their luminescence, a feature ... more Large Stokes shift fast emitters show a negligible reabsorption of their luminescence, a feature highly desirable for several applications such as fluorescence imaging, solar-light managing, and fabricating sensitive scintillating detectors for medical imaging and high-rate high-energy physics experiments. Here we obtain high efficiency luminescence with significant Stokes shift by exploiting fluorescent conjugated acene building blocks arranged in nanocrystals. Two ligands of equal molecular length and connectivity, yet complementary electronic properties, are co-assembled by zirconium oxy-hydroxy clusters, generating crystalline hetero-ligand metal-organic framework (MOF) nanocrystals. The diffusion of singlet excitons within the MOF and the matching of ligands absorption and emission properties enables an ultrafast activation of the low energy emission in the 100 ps time scale. The hybrid nanocrystals show a fluorescence quantum efficiency of ~60% and a Stokes shift as large as 7...
The Journal of Physical Chemistry A, 2000
Single-file diffusion behavior is expected for atoms and molecules in one-dimensional gas phases ... more Single-file diffusion behavior is expected for atoms and molecules in one-dimensional gas phases of nanochannels with transverse dimensions that do not allow for the particles to bypass each other. Although single-file diffusion may play an important role in a wide range of industrial catalytic, geologic, and biological processes, experimental evidence is scarce despite the fact that the dynamics differ substantially from ordinary diffusion. We demonstrate the application of continuous-flow laser-polarized 129 Xe NMR spectroscopy for the study of gas transport into the effectively one-dimensional channels of a microporous material. The novel methodology makes it possible to monitor diffusion over a time scale of tens of seconds, often inaccessible by conventional NMR experiments. The technique can also be applied to systems with very small mobility factors or diffusion constants that are difficult to determine by currently available methods for diffusion measurement. Experiments using xenon in nanochannel systems can distinguish between unidirectional diffusion and single-file diffusion. The experimental observations indicate that single-file behavior for xenon in an organic nanochannel is persistent even at long diffusion times of over tens of seconds. Finally, using continuousflow laser-polarized 129 Xe NMR spectroscopy, we describe an intriguing correlation between the observed NMR line shape of xenon within the nanochannels and the gas transport into these channels.
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Papers by Angiolina Comotti