WO3/ZrO2 catalysts prepared by different methods are distinct in their catalytic behaviour. In this work, WO3/ZrO2 catalysts prepared by impregnating Zr(OH)4 and crystallized ZrO2 and then calcining at selected temperatures were characterized by means of qualitative and quantitative Raman spectroscopy. The results showed that ZrO2 in WO3/ZrO2 obtained from crystallized ZrO2 (referred to as WZ) is monoclinic, whereas ZrO2 in WO3/ZrO2 obtained from Zr(OH)4 (referred to as WZH) is in a metastable tetragonal phase as long as the WO3 content is high enough. In both WZ and WZH, WO3 is dispersed on ZrO2 as a monolayer, and the dispersion capacity per 100 m2 of ZrO2 is in good agreement with that estimated from the close‐packed monolayer model. However, since the specific surface areas of WZH samples are larger than those of WZ samples, the dispersion capacity per gram of ZrO2 of WZH is larger than that of WZ. A chemical reaction may occur between WO3 and the surface of Zr(OH)4 (or tetragonal ZrO2) at high temperature, and then some superacid sites are created on the surface of the WZH sample.

A series of mixed-ligand coordination complexes, namely, [Cd 2(bimb) 2(L (1)) 2] ( 1), [Cd(bpimb) 0.5(L (2))(H 2O)] ( 2), [Zn 5(bpib) 2(L (3)) 4(OH) 2(H 2O) 2] ( 3), [Zn(bpib) 0.5(L (4))] ( 4), and [Cd(bib)(L (4))] ( 5), where bimb = 1,4-bis((1 H-imidazol-1-yl)methyl)benzene, bpimb = 1,4-bis((2-(pyridin-2-yl)-1 H-imidazol-1-yl)methyl)benzene, bpib = 1,4-bis(2-(pyridin-2-yl)-1 H-imidazol-1-yl)butane, bib = 1,4-bis(1 H-imidazol-1-yl)butane, H 2L (1) = 4-((4-(dihydroxymethyl)phenoxy)methyl)benzoic acid, H 2L (2) = 4,4'-methylenebis(oxy)dibenzoic acid, H 2L (3) = 3,3'-methylenebis(oxy)dibenzoic acid, and H 2L (4) = 4,4'-(2,2'-oxybis(ethane-2,1-diyl)bis(oxy))dibenzoic acid, have been synthesized under hydrothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and thermogravimetric (TG) analyses. In 1, (L (1)) (2-) anions link the metal-neutral ligand subunits to generate a 2-fold parallel interpenetrating net with the 6 (3) topology. In 2- 4, neutral ligands connect the various metal-carboxylic ligand subunits to give a 2-fold parallel interpenetrating net with (4,4) topology in 2, a 2-fold parallel interpenetrating net with (3,6)-connected topology in 3, and a 3-fold parallel interpenetrating net with (4,4) topology in 4. Compounds 1- 4 display both polyrotaxane and polycatenane characters. Compound 5 is a 5-fold parallel interpenetrating net with (4,4) topology. By careful inspection of these structures, we find that different topological structures showing both polyrotaxane and polycatenane characters have been achieved with increase of the carboxylic ligand length. It is believed that various carboxylic ligands and N-donor ligands with different coordination modes and conformations are important for the formation of the different structures. In addition, the luminescent properties of these compounds are discussed.

Orange and red thermally activated delayed fluorescence emitters have been developed for high performance vacuum-deposited and solution-processable organic light-emitting diodes.

Composite molecule-nanoparticle hybrid systems have recently emerged as important materials for applications ranging from chemical sensing to nanoscale electronics. However, creating reproducible and repeatable composite materials with precise properties has remained one of the primary challenges to the implementation of these technologies. Understanding the sources of variation that dominate the assembly and transport behavior is essential for the advancement of nanoparticle-array based devices. In this work, we use a combination of charge-transport measurements, electron microscopy, and optical characterization techniques to determine the role of morphology and structure on the charge transport properties of 2-dimensional monolayer arrays of molecularly-interlinked Au nanoparticles. Using these techniques we are able to determine the role of both assembly-dependent and particle-dependent defects on the conductivities of the films. These results demonstrate that assembly processes dominate the dispersion of conductance values, while nanoparticle and ligand features dictate the mean value of the conductance. By performing a systematic study of the conductance of these arrays as a function of nanoparticle size we are able to extract the carrier mobility for specific molecular ligands. We show that nanoparticle polydispersity correlates with the void density in the array, and that because of this correlation it is possible to accurately determine the void density within the array directly from conductance measurements. These results demonstrate that conductance-based measurements can be used to accurately and non-destructively determine the morphological and structural properties of these hybrid arrays, and thus provide a characterization platform that helps move 2-dimensional nanoparticle arrays toward robust and reproducible electronic systems.

Imprinted polymers were prepared for nicotinamide and its positional isomers. The influence of porogenic solvent and functional monomer on recognition properties of the polymer was compared. The results indicated that two functional groups, the heterocyclic nitrogen and the amide group, in the nicotinamide or isonicotinamide molecule have a synergistic effect in binding to the polymer. The polymers prepared with nicotinamide and isonicotinamide can be used as HPLC stationary phase for the separation of positional isomers of nicotinamide or isonicotinamide, while the polymer prepared with picolinamide showed no specificity toward the template. The mechanisms for the differences in recognition are discussed. In addition to the retention of polymers to their templates the polymers also displayed excellent retention to nicotinic acid and isonicotinic acid, compounds structurally similar to the template. This dual recognition property of the polymer may be useful in circumstances where the preparation of a polymer for a specific template may be problematic because of poor stability or solubility.