Probing ligand conformation and net dimensionality in a series of tetraphenylethene-based metal-organic frameworks.

Tetraphenylethene-based ligands with lowered symmetry are promising building blocks for the construction of novel luminescent metal-organic frameworks (MOFs). However, few examples have been reported, and predicting the ligand conformation and the dimensionality of the resulting MOF remains challenging. In order to uncover how synthetic conditions and accessible ligand conformations may affect the resulting MOF structure, four new MOF structures were synthesized under solvothermal conditions using the meta-coordinated tetraphenylethene-based ligand -ETTC and paddlewheel SBUs composed of Co(II), Cu(II), and Zn(II).

Two Cd-Based Luminescent Coordination Polymers Constructed from a Truncated Linker.

Two cadmium coordination polymers, WSU-30 and WSU-31, were synthesized through solvothermal methods by using the low-symmetry TPE-based linker -HETTC. The -HETTC linker and both coordination polymers were fully characterized by using single-crystal X-ray diffraction, infrared spectroscopy, and photoluminescent emission spectroscopy. Structural analysis of WSU-30 and WSU-31 showed that each compound contains previously unknown tetranuclear cadmium(II) secondary building units.

Update of primary Helicobacter pylori resistance to antimicrobials in Brussels, Belgium.

This study aimed to follow the trend of primary antimicrobial resistance in Helicobacter pylori isolates obtained from several centers in Brussels. We observed increasing rates of primary resistance to macrolides (10.5% to 18%) to nitro-imidazoles (28% to 40%) and to fluoroquinolones (12.

Dielectric back scattering patterns for light trapping in thin-film Si solar cells.

We experimentally compare the light trapping efficiency of dielectric and metallic backscattering patterns in thin-film a-Si:H solar cells. We compare devices with randomly patterned Ag back contacts that are covered with either flat or patterned aluminum-doped ZnO (AZO) buffer layers and find the nanostructure at the AZO/a-Si:H interface is key to achieve efficient light trapping. Simulations show that purely dielectric scattering patterns with flat Ag and a patterned AZO/a-Si:H interface can outperform geometries in which the Ag is also patterned.

Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells.

Nanophotonic structures have attracted attention for light trapping in solar cells with the potential to manage and direct light absorption on the nanoscale. While both randomly textured and nanophotonic structures have been investigated, the relationship between photocurrent and the spatial correlations of random or designed surfaces has been unclear. Here we systematically design pseudorandom arrays of nanostructures based on their power spectral density, and correlate the spatial frequencies with measured and simulated photocurrent.