Benton Bennett (nicdress1)

The photoablation process is sufficiently precise that the smallest lateral feature size fabricated reproducibly to date, ∼350 nm, appears to be limited primarily by the photomask itself. Examples of the versatility and precision of this photolithographic process include the fabrication of arrays of aluminum nanomirrors, each atop a 350 nm or 1 μm-diameter Si post, as well as optical components such as transmission gratings or Fresnel lenses photoablated into PMMA.The synthesis and characterisation of a series of magnesium complexes bearing sterically demanding amidinate ligands is reported; this includes magneisum amides (1a and 1b), hydrides (3a and 3b) and alkyl complexes (2b). The solid and solution state behaviour of the complexes has been investigated using single crystal X-ray diffraction and NMR spectroscopy, revealing the magnesium hydrides to exist as dimers in the solid state, dispite the sterically demanding ligand systems and showing a degree of monomeric character in solution. The stoichiometric and catalytic activity of the amidinate complexes were investigated, with the complexes found to efficiently mediate both the hydroamination of N,N'-diisopropylcarbodiimide and the Tishchenko reaction. The metal hydrides are highly reactive towards coordinating substrates, showing a significant increase in catalytic rate compared with more ubiquitous β-diketiminate magnesium hydrides.Seven new carbohydrate-bistriazole hybrid molecules were designed taking into consideration the crescent shaped active site of ribonuclease A (RNase A). In this case, the β-d-ribofuranose structure was used as the basic building unit; both the C1 and C4 arms protruding out towards the β-face of the tetrahydrofuran moiety of the ribose sugar provided an overall "U" shape to the basic building block. Several combinations of bistriazole moieties were constructed on the two arms of this basic building block. These mono- and/or bis-substituted 1,2,3-triazole units were linked to acidic functional groups because of the overall basic nature of the hydrolytic site of RNase A. All these compounds were efficient competitive inhibitors of RNase A with inhibition constants (Ki) in the micromolar range. In contrast to the carboxylic acid-modified hybrid molecules, molecules carrying sulfonic acids were found to be more potent because of the stronger interactions with the positively charged active site. The most efficient inhibitor of the series was the disulfonic acid-functionalized carbohydrate-bis-triazole hybrid molecule. Docking studies disclosed that the molecule, because of its well defined "U" shape with flexible arms, fits effectively in the active site; moreover, in all cases, besides the acid groups, the triazole and sugar rings also actively participated in creating the hydrogen bonding network in the cavity of the enzyme active site.Herein, we suggest a unique approach to control the growth of hybrid crystals of silicotungstic acid (STA) by introducing a poly(ethylene oxide) (PEO)-containing block copolymer and a poly(methyl methacrylate)-b-poly(ethylene oxide)-b-poly(methyl methacrylate) block copolymer (MEM BCP). Remarkably, perfectly straight ribbon-like lamellae with a uniform width and a large length/width ratio (>200) can be obtained. The length of hybrid nanoribbons can be tuned by annealing time and temperature, whereas the width is dependent on the molecular weight of the PEO mid-block. The stability of hybrid nanoribbons has been investigated against solvent vapor, high temperatures and the presence of phosphotungstic acid (PTA). The formation of hybrid nanoribbons leads to enhanced mechanical properties and proton conductivities of STA hybrid nanocomposites. This effective approach will provide a representative strategy to the control of crystalline hybrid materials in the solid state.This review focusses on unique material modification and signal amplification strategies reported in developing photoelectrochemical (PEC) biosen