Estructures supramoleculars de Au(I) emprades en processos de reconeixement molecular.

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Curs: 2015, Tutora: Dra. Laura Rodríguez RaurellIn the latest years there has been an increasing interest in the study of certain organometallic gold (I) complexes, due to the great variety of supramolecular structures that they form. Through the establishment of intramolecular weak interactions a process of self-assembly occurs; structures such as fibres, micelles and vesicles have been reported and some have proven to be gelators. A wide range of applications have been envisioned for these complexes in several fields: medicine, materials chemistry, applications in detectors, light harvesting and catalysis. In the work presented herein, the study of two families of organometallic gold (I) complexes is presented. The first family are neutral complexes with general formula [[Au(4-ethynylbipyridine)(L)], and the second are charged complexes with general formula [Au(N-methyl-4-ethynylpyridine)(L)]X, where X=iodide, triflate and perchlorate. The ligands L are phosphines DAPTA and PTA. The purpose of this work is to study several properties of these complexes to better understand their nature. The aggregation process (or self-assembly) over time, as a function of concentration and the solvent will be studied for the first neutral complexes. In addition, molecular recognition studies with three lanthanide cations will be performed. The synthesis and later characterization of complexes [Au(N-methyl-4-ethynylpyridine)(L)]X with X=iodide and triflate will be carried out. Several unsuccessful attempts to synthetize the complex with X=perchlorate will be described in detail. Finally, aggregation studies have been carried out: their solvatochromism has been studied and their supramolecular structures have been observed through optical microscopy

Tuning supramolecular aurophilic structures: the effect of counterion, positive charge and solvent

The synthesis of the cationic gold(I) complexes [Au(CuCC5H4N)(CH3-PTA)] X (X = I, 1; X = OTf, 4), [Au(C equivalent to CC5H4N-CH3)(PTA)] X (X = I, 2; X = OTf = 5; PTA = 1,3,5-triaza-7-phosphatricyclo[3.3.1.13.7]decane) and [Au(CuCC5H4N-CH3)(DAPTA)] X (X = I, 3; X = OTf = 6, DAPTA = 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[ 3.3.1]nonane) results in cationic complexes with unexpected supramolecular assemblies in water ranging from rod-like structures (1) to vesicles (2 and 3) and square-like structures (5 and 6). These morphologies are completely different from the fibers previously obtained with their parent neutral complexes [Au(C equivalent to C5H4N)(PTA)] and [Au(C equivalent to C5H4N)(DAPTA)]. Nevertheless, the introduction of triflate as a counterion in 1 (complex 4) gives rise to the formation of a highly soluble complex in water which does not display any significant aggregation in solution. These results reveal the importance of the introduction of a positive charge on global supramolecular assemblies and how the counterion can also modify the resulting package. Interestingly, we have also proved that the aggregation of complexes 2, 3, 5 and 6 is also affected by the solvent with direct influence on their absorption and emission properties and the global morphology of the aggregates.Postprint (author's final draft

Resveratrol activates antioxidant protective mechanisms in cellular models of Alzheimer’s disease inflammation

Resveratrol is a natural phenolic compound with known benefits against neurodegeneration. We analyzed in vitro the protective mechanisms of resveratrol against the proinflammatory monomeric C-reactive protein (mCRP). mCRP increases the risk of AD after stroke and we previously demonstrated that intracerebral mCRP induces AD-like dementia in mice. Here, we used BV2 microglia treated with mCRP for 24 h in the presence or absence of resveratrol. Cells and conditioned media were collected for analysis. Lipopolysaccharide (LPS) has also been implicated in AD progression and so LPS was used as a resveratrol-sensitive reference agent. mCRP at the concentration of 50 µg/mL activated the nitric oxide pathway and the NLRP3 inflammasome pathway. Furthermore, mCRP induced cyclooxygenase-2 and the release of proinflammatory cytokines. Resveratrol effectively inhibited these changes and increased the expression of the antioxidant enzyme genes Cat and Sod2. As central mechanisms of defense, resveratrol activated the hub genes Sirt1 and Nfe2l2 and inhibited the nuclear translocation of the signal transducer NF-ĸB. Proinflammatory changes induced by mCRP in primary mixed glial cultures were also protected by resveratrol. This work provides a mechanistic insight into the protective benefits of resveratrol in preventing the risk of AD induced by proinflammatory agents

Tuning supramolecular aurophilic structures: the effect of counterion, positive charge and solvent

The synthesis of the cationic gold(I) complexes [Au(C≡CC5H4N)(CH3-PTA)]X (X = I, 1; X = OTf, 4), [Au(C≡CC5H4N-CH3)(PTA)]X (X = I, 2; X = OTf = 5; PTA = 1,3,5-triaza-7-phosphatricyclo[3.3.1.13.7]decane) and [Au(C≡CC5H4N-CH3)(DAPTA)]X (X = I, 3; X = OTf = 6, DAPTA = 3,7-diacetyl-1,3,7-triaza-5- phosphabicyclo[3.3.1]nonane) gives cationic complexes showing unexpected supramolecular assemblies in water going from rod-like structures (1) to vesicles (2 and 3) and square-like structures (5 and 6). These morphologies are completely different from the fibers previously obtained with their parent neutral complexes [Au(C≡C5H4N)(PTA)] and [Au(C≡C5H4N)(DAPTA)]. Nevertheless, the introduction of triflate as counterion in 1 (complex 4) gives rise to the formation of highly soluble complex in water which does not display any significant aggregation in solution. These results reveal the importance of the introduction of a positive charge on the global supramolecular assemblies and how the counterion can modify also the resulting package. Interestingly, we have also proved that the aggregation of complexes 2, 3, 5 and 6 is also affected by the solvent with direct influence on their absorption and emission properties and the global morphology of the aggregates

MAMMALS IN PORTUGAL : A data set of terrestrial, volant, and marine mammal occurrences in P ortugal

Mammals are threatened worldwide, with 26% of all species being includedin the IUCN threatened categories. This overall pattern is primarily associatedwith habitat loss or degradation, and human persecution for terrestrial mam-mals, and pollution, open net fishing, climate change, and prey depletion formarine mammals. Mammals play a key role in maintaining ecosystems func-tionality and resilience, and therefore information on their distribution is cru-cial to delineate and support conservation actions. MAMMALS INPORTUGAL is a publicly available data set compiling unpublishedgeoreferenced occurrence records of 92 terrestrial, volant, and marine mam-mals in mainland Portugal and archipelagos of the Azores and Madeira thatincludes 105,026 data entries between 1873 and 2021 (72% of the data occur-ring in 2000 and 2021). The methods used to collect the data were: live obser-vations/captures (43%), sign surveys (35%), camera trapping (16%),bioacoustics surveys (4%) and radiotracking, and inquiries that represent lessthan 1% of the records. The data set includes 13 types of records: (1) burrowsjsoil moundsjtunnel, (2) capture, (3) colony, (4) dead animaljhairjskullsjjaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8),observation in shelters, (9) photo trappingjvideo, (10) predators dietjpelletsjpine cones/nuts, (11) scatjtrackjditch, (12) telemetry and (13) vocalizationjecholocation. The spatial uncertainty of most records ranges between 0 and100 m (76%). Rodentia (n=31,573) has the highest number of records followedby Chiroptera (n=18,857), Carnivora (n=18,594), Lagomorpha (n=17,496),Cetartiodactyla (n=11,568) and Eulipotyphla (n=7008). The data setincludes records of species classified by the IUCN as threatened(e.g.,Oryctolagus cuniculus[n=12,159],Monachus monachus[n=1,512],andLynx pardinus[n=197]). We believe that this data set may stimulate thepublication of other European countries data sets that would certainly contrib-ute to ecology and conservation-related research, and therefore assisting onthe development of more accurate and tailored conservation managementstrategies for each species. There are no copyright restrictions; please cite thisdata paper when the data are used in publications.info:eu-repo/semantics/publishedVersio

Mammals in Portugal: a data set of terrestrial, volant, and marine mammal occurrences in Portugal

Mammals are threatened worldwide, with ~26% of all species being included in the IUCN threatened categories. This overall pattern is primarily associated with habitat loss or degradation, and human persecution for terrestrial mammals, and pollution, open net fishing, climate change, and prey depletion for marine mammals. Mammals play a key role in maintaining ecosystems functionality and resilience, and therefore information on their distribution is crucial to delineate and support conservation actions. MAMMALS IN PORTUGAL is a publicly available data set compiling unpublished georeferenced occurrence records of 92 terrestrial, volant, and marine mammals in mainland Portugal and archipelagos of the Azores and Madeira that includes 105,026 data entries between 1873 and 2021 (72% of the data occurring in 2000 and 2021). The methods used to collect the data were: live observations/captures (43%), sign surveys (35%), camera trapping (16%), bioacoustics surveys (4%) and radiotracking, and inquiries that represent less than 1% of the records. The data set includes 13 types of records: (1) burrows | soil mounds | tunnel, (2) capture, (3) colony, (4) dead animal | hair | skulls | jaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8), observation in shelters, (9) photo trapping | video, (10) predators diet | pellets | pine cones/nuts, (11) scat | track | ditch, (12) telemetry and (13) vocalization | echolocation. The spatial uncertainty of most records ranges between 0 and 100 m (76%). Rodentia (n =31,573) has the highest number of records followed by Chiroptera (n = 18,857), Carnivora (n = 18,594), Lagomorpha (n = 17,496), Cetartiodactyla (n = 11,568) and Eulipotyphla (n = 7008). The data set includes records of species classified by the IUCN as threatened (e.g., Oryctolagus cuniculus [n = 12,159], Monachus monachus [n = 1,512], and Lynx pardinus [n = 197]). We believe that this data set may stimulate the publication of other European countries data sets that would certainly contribute to ecology and conservation-related research, and therefore assisting on the development of more accurate and tailored conservation management strategies for each species. There are no copyright restrictions; please cite this data paper when the data are used in publications

Tuning supramolecular aurophilic structures: the effect of counterion, positive charge and solvent

The synthesis of the cationic gold(I) complexes [Au(CuCC5H4N)(CH3-PTA)] X (X = I, 1; X = OTf, 4), [Au(C equivalent to CC5H4N-CH3)(PTA)] X (X = I, 2; X = OTf = 5; PTA = 1,3,5-triaza-7-phosphatricyclo[3.3.1.13.7]decane) and [Au(CuCC5H4N-CH3)(DAPTA)] X (X = I, 3; X = OTf = 6, DAPTA = 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[ 3.3.1]nonane) results in cationic complexes with unexpected supramolecular assemblies in water ranging from rod-like structures (1) to vesicles (2 and 3) and square-like structures (5 and 6). These morphologies are completely different from the fibers previously obtained with their parent neutral complexes [Au(C equivalent to C5H4N)(PTA)] and [Au(C equivalent to C5H4N)(DAPTA)]. Nevertheless, the introduction of triflate as a counterion in 1 (complex 4) gives rise to the formation of a highly soluble complex in water which does not display any significant aggregation in solution. These results reveal the importance of the introduction of a positive charge on global supramolecular assemblies and how the counterion can also modify the resulting package. Interestingly, we have also proved that the aggregation of complexes 2, 3, 5 and 6 is also affected by the solvent with direct influence on their absorption and emission properties and the global morphology of the aggregates

Tuning supramolecular aurophilic structures: the effect of counterion, positive charge and solvent

The synthesis of the cationic gold(I) complexes [Au(C≡CC5H4N)(CH3-PTA)]X (X = I, 1; X = OTf, 4), [Au(C≡CC5H4N-CH3)(PTA)]X (X = I, 2; X = OTf = 5; PTA = 1,3,5-triaza-7-phosphatricyclo[3.3.1.13.7]decane) and [Au(C≡CC5H4N-CH3)(DAPTA)]X (X = I, 3; X = OTf = 6, DAPTA = 3,7-diacetyl-1,3,7-triaza-5- phosphabicyclo[3.3.1]nonane) gives cationic complexes showing unexpected supramolecular assemblies in water going from rod-like structures (1) to vesicles (2 and 3) and square-like structures (5 and 6). These morphologies are completely different from the fibers previously obtained with their parent neutral complexes [Au(C≡C5H4N)(PTA)] and [Au(C≡C5H4N)(DAPTA)]. Nevertheless, the introduction of triflate as counterion in 1 (complex 4) gives rise to the formation of highly soluble complex in water which does not display any significant aggregation in solution. These results reveal the importance of the introduction of a positive charge on the global supramolecular assemblies and how the counterion can modify also the resulting package. Interestingly, we have also proved that the aggregation of complexes 2, 3, 5 and 6 is also affected by the solvent with direct influence on their absorption and emission properties and the global morphology of the aggregates

Reversible Self-Assembly of Water-Soluble Gold(I) Complexes

This is an open access article published under an ACS AuthorChoice License. See Standard ACS AuthorChoice/Editors' Choice Usage Agreement - https://pubs.acs.org/page/policy/authorchoice_termsofuse.htmlThe reaction of the gold polymers containing bipyridyl and terpyridyl units, [Au(C≡CCHN)] and [Au(C≡CCHN)], with the water-soluble phosphines 1,3,5-triaza-7-phosphatricyclo[3.3.1.13.7]decane and 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane gives rise to the formation of four gold(I) alkynyl complexes that self-assemble in water (HO) and dimethyl sulfoxide (DMSO), through different intermolecular interactions, with an impact on the observed luminescence displayed by the supramolecular assemblies. A detailed analysis carried out by NMR studies performed in different DMSO/deuterated HO mixtures indicates the presence of two different assembly modes in the aggregates: (i) chain assemblies, which are based mainly on aurophilic interactions, and (ii) stacked assemblies, which are based on Au···π and π···π interactions. These different supramolecular environments can also be detected by their intrinsic optical properties (differences in absorption and emission spectra) and are predicted by the changes in the relative binding energy from density functional theory calculations carried out in DMSO and HO. Small-angle X-ray scattering (SAXS) experiments performed in the same mixture of solvents are in agreement with the formation of aggregates in all cases. The aromatic units chosen, bipyridine and terpyridine, allow the use of external stimuli to reversibly change the aggregation state of the supramolecular assemblies. Interaction with the Zn cation is observed to disassemble the aggregates, while encapsulating agents competing for Zn complexation revert the process to the aggregation stage, as verified by SAXS and NMR. The adaptive nature of the supramolecular assemblies to the metal-ion content is accompanied by significant changes in the absorption and emission spectra, signaling the aggregation state and also the content on Zn

Le Courrier

19 juin 18381838/06/19 (N170)