RESUMO
The safe storage of flammable gases, such as acetylene, is essential for current industrial purposes. However, the narrow pressure (P) and temperature range required for the industrial use of pure acetylene (100 < P < 200 kPa at 298 K) and its explosive behaviour at higher pressures make its storage and release challenging. Flexible metal-organic frameworks that exhibit a gated adsorption/desorption behaviour-in which guest uptake and release occur above threshold pressures, usually accompanied by framework deformations-have shown promise as storage adsorbents. Herein, the pressures for gas uptake and release of a series of zinc-based mixed-ligand catenated metal-organic frameworks were controlled by decorating its ligands with two different functional groups and changing their ratio. This affects the deformation energy of the framework, which in turn controls the gated behaviour. The materials offer good performances for acetylene storage with a usable capacity of ~90 v/v (77% of the overall amount) at 298 K and under a practical pressure range (100-150 kPa).
RESUMO
The first structure elucidation of a lamellar gold thiolate coordination polymer is described. [Au(p-SPhCO2Me)]n is obtained from the simultaneous esterification of mercaptobenzoic acid and reduction of the Au(iii) precursor. Despite the presence of aurophilic interactions, the intense phosphorescence (QY â¼ 70%) originates from intra-ligand and metal-to-ligand transitions.
RESUMO
A new organo-soluble [60]fullerene hexaadduct bearing twelve thiocyanate functions has been synthesized and successfully used as a stabilizing/assembling agent to assemble homogeneous sub-3 nm gold nanoparticles into extended tridimensional networks.
RESUMO
Research interest in ultra small gold thiolate clusters has been rising in recent years for the challenges they offer to bring together properties of nanoscience and well-defined materials from molecular chemistry. Here, a new atomically well-defined Au10 gold nanocluster surrounded by ten 4-aminothiophenolate ligands is reported. Its synthesis followed the similar conditions reported for the elaboration of Au144(SR)60, but because the reactivity of thiophenol ligands is different from alkanethiol derivates, smaller Au10 clusters were formed. Different techniques, such as ESI-MS, elemental analysis, XRD, TGA, XPS and UV-vis-NIR experiments, have been carried out to determine the Au10(SPh-pNH2)10 formula. Photoemission experiment has been done and reveals that the Au10 clusters are weakly luminescent as opposed to the amino-based ultra-small gold clusters. This observation points out that the emission of gold thiolate clusters is highly dependent on both the structure of the gold core and the type of the ligands at the surface. In addition, ultra-small amino-functionalized clusters offer the opportunity for extended work on self-assembling networks or deposition on substrates for nanotechnologies or catalytic applications.
RESUMO
New Au(25) nanoclusters stabilized by heterotopic 4-aminothiophenolate ligands (HSPhNH(2)) have been isolated with a yield of ~70%. The nanoclusters formula determined by ESI-MS is Au(25)(SPhNH(2))(17), with the 18(th) position occupied by an amine or DMF molecules to close their electronic shell.