Murray V. Baker

Enhanced deep-blue emission from Pt(II) complexes bound to 2-pyridyltetrazolate and an ortho-xylene-linked bis(NHC)cyclophane

The coordination of 2-pyridyltetrazolate and ortho-xylene-linked bis(NHC)cyclophane to Pt(II) yielded a novel complex characterised by enhanced pure deep-blue emission, whose intensity can be modulated via methylation of the tetrazole ring.

Dinuclear Au(I) N-heterocyclic carbene complexes derived from unsymmetrical azolium cyclophane salts: potential probes for live cell imaging applications

We have synthesized a new series of azolium cyclophanes and used them as precursors of inherently luminescent dinuclear Au(i)-N-heterocyclic carbene (NHC) complexes. The azolium cyclophanes contained two azolium groups (either imidazolium or benzimidazolium), an o-xylyl group, and an alkyl linker chain (either C2, C3 or C4). All of the azolium cyclophanes were characterised by X-ray diffraction studies and VT NMR studies, and all were fluxional in solution on the NMR timescale. The C3- and C4-linked azolium cyclophanes served as precursors of Au2L2(2+) complexes (L is a cyclophane bis(NHC) ligand). Due to the unsymmetrical nature of the azolium cyclophanes, the Au2L2(2+) complexes each existed as cis and trans isomers. X-ray diffraction studies showed that the Au2L2(2+) complexes had short intramolecular AuAu distances, in the range 2.9-3.3 Å, suggestive of an aurophilic attraction, presumably as a consequence of the geometrical constraints imposed by the cyclophane bis(NHC) ligands. The complexes having the shortest AuAu distances (i.e., those based on C3-linked cyclophanes) exhibited intense luminescence in solution. The uptake of one of the dinuclear Au-NHC complexes by tumorigenic cells, and its subsequent distribution and toxicity in the cells, was monitored by luminescence microscopy over 6 h and proliferation measurements, respectively.

Improving the cellular invasion into PHEMA sponges by incorporation of the RGD peptide ligand: The use of copolymerization as a means to functionalize PHEMA sponges

A monomer that contained the RGD ligand motif was synthesized and copolymerized with 2-hydroxyethyl methacrylate using polymerization-induced phase separation methods to form poly(2-hydroxyethyl methacrylate)-based hydrogel sponges. The sponges had morphologies of aggregated polymer droplets and interconnected pores, the pores having dimensions in the order of 10 μm typical of PHEMA sponges. RGD-containing moieties appeared to be evenly distributed through the polymer droplets. Compared to PHEMA sponges that were not functionalized with RGD, the new sponges containing RGD allowed greater invasion by human corneal epithelial cells, by advancing the attachment of cells to the surface of the polymer droplets.

Growth and XPS Characterization of Anodic Telluride Films on Hg1-xCdxTe

An anodic tellurization process to grow native telluride films on Hg 1-x Cd x Te is described. This process requires two steps : first the growth of an anodic sulfide/oxide film and second the conversion of this film into an anodic telluride film. XPS studies suggest that the total conversion of the anodic sulfide/oxide film into an anodic telluride film is possible. The concentration of tellurium in the anodically grown telluride films can be controlled by controlling the concentration of sulfur and oxygen in the starting film.

Calixarene/azolium cyclophane hybrids: synthesis, structure and conformations

The synthesis, structure, and conformational behaviour of three imidazolium cyclophanes that incorporate one or two 4-tert-butylphenol or 4-tert-butylanisole groups as meta-disubstituted linkers in the macrocycle is described. The cyclophanes containing anisole moieties adopt a cone conformation in the solid state, which, in solution, is not labile on the NMR timescale. The cyclophanes containing one or two phenol moieties adopt conformations other than the cone in the solid state and are labile in solution on the NMR timescale. The phenol cyclophanes are readily deprotonated, and structural and conformational studies for a variety of the associated cyclophanes are also reported.

Charging mechanism of AlGaN/GaN open-gate pH sensor and electrolyte interface

The charging mechanism of the interface between an AlGaN/GaN based open-gate ion-sensitive field-effect transistor and electrolyte is studied theoretically. Density functional theory calculations are performed to obtain the energy minimum structure of the surface oxide and electrolyte interface. Thermodynamics based relations are employed to obtain the double layer parameters. An analytical model is applied to study the carrier density modulation of the AlGaN/GaN heterostrucrure by the influence of the surface charge.

Mercury complexes of an N-heterocyclic carbene derived from a calixarene/azolium cyclophane hybrid

Reaction of mercuric acetate with an imidazolium-linked cyclophane incorporating 2,6-phenolic moieties results in formation of an interesting new N-heterocyclic carbene (NHC) complex of mercury. The new complex is cationic and binuclear, incorporating two mercury centres and two bis(NHC) ligands, each mercury atom being bound by two NHC moieties and two phenol/phenoxy moieties. Forms of the complex having coordinating (

An investigation into signal stability during measurement of AlGaN/GaN transistor-based chemical sensors

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