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A description is presented on fabrication of 2D arrays of Au nanorods using nanoporous anodized aluminum oxide (AAO) templates coated with polyethylenimine (PEI), with very fine control over nanorod height. Uniform growth rate is determined by the adsorbed PEI matrix, which controls the growth kinetics of the grains comprising the nanorods.

Gold nanorods excited at 830 nm on a far-field laser-scanning microscope produced strong two-photon luminescence (TPL) intensities, with a [cos.sup.4] dependence on the incident polarization. The TPL excitation spectrum can be superimposed onto the longitudinal plasmon band, indicating a plasmon-enhanced two-photon absorption cross section. The TPL signal from a single nanorod is 58 times that of the two-photon fluorescence signal from a single rhodamine molecule. The application of gold nanorods as TPL imaging agents is demonstrated by in vivo imaging of single nanorods flowing in mouse ear blood vessels. in vivo imaging | plasmon resonance | multiphoton | nonlinear optics

Results reveal that the reductive cleavage of anisylidene acetals by BH3/Bu2BOTf can selectively produce either regioisomer, simply by adjusting the reaction temperatures and reagent concentrations. Reductive ring opening at low temperatures is determined to be compatible with sensitive functional groups such as allyl and enol ethers and other ketals.

The self-assembled monolayers (SAMs) of dodecanethiol (DDT), octadecanethiol (ODT), and resorcinarene C10 tetrasulfide (RC10TS) on Au(111) are characterized by scanning tunneling spectroscopy. The leakage current densities across DDT and RC10TS SAMs on Au are estimated.

A new empirical approach to model the solvent effects in protein-membrane complexes is proposed. The potential of the new method for studying large molecular systems is demonstrated with the example of two transmembrane proteins, bacteriorhodopsin and rhodopsin.

15N nuclear magnetic resonance spectroscopy was employed to investigate changes in nuclear Overhauser effects and T1 relaxation rates, with viscosity as a function of temperature using a mixed solvent system composed of 8.8 M dimethyl sulfoxide in water as test solution. The results indicated that in highly viscous solutions, even simple molecules exhibit complex motional behavior that cannot be readily explained by the currently available levels of theory for estimating the intermolecular contribution toward their 15N dipole-dipole relaxations.

A study evaluated the conformations of the H-type II blood group trisaccharides by the conformational models of C-substituted C-glycosides where the C-glycosidic bond has the gauche exo-anomeric form. The H-type II trisaccharide has similar binding affinity to the respective carbon analog as indicated by the linkage with the lectin I of Ulex europaeus.

The procedure for synthesis of C-trisaccharides, the carbon analogs of the human blood group determinant H-type II, is similar to that employed for 2-hydroxy-2-desacetamido analogs. Proton NMR spectroscopic analysis shows that the rational structural modification initiates interglycosidic linkages to achieve staggered conformations, which are mutually independent.

Conformation analysis of the 1,1-linked C-disaccharides, synthesized by unified strategy, reveal that alpha,alpha-C-trehalose and beta, beta-C-trehalose have a single conformer with both C-glycosidic bonds, adopting an exo-anomeric conformation. In alpha,beta-C-trehalose, the axial C-glycosidic bond is conformationally more rigid and is exo-anomeric, and the equatorial glycosidic bond deviates from the exo-anomeric conformation. Conformational preference is affected by the inversion of C.2 or C.2' hydroxyl group.

Sulfated epitopes of [alpha]-glucosamine (GlcN sulfoforms) are prepared by using solid-phase synthesis as models of internal glucosamines within heparan sulfate. The fragmentation analysis has distinguished GlcN sulfoforms bearing the relatively rare 3-O-sulfate from isomers with the more common 6-O-sulfate.

Conformational analysis of the (6S)- and (6R)-C methyl-substituted beta-D-GlcNAc monosaccharides indicates that stereodefined methyl groups impose predictable conformational biases on the exocyclic C-5-C-6 bond as determined by (super 1)H-(super 1)H and (super 13)C-(super 1)H coupling constants. Variable-temperature NMR experiments in methanol-d4 are performed to determine deltadeltaH and deltadeltaS values derived from the two lowest energy conformers.

An efficient synthesis of trisaccharide, the unnatural enantiomer of the H-type II blood group determinant, is described. D-glucose can be used to prepare the mirror-image analogues of carbohydrates.

Frozen-solution conformational analysis (FrSCA) offers an attractive alternative to solution-based NMR methods of conformational analysis, with its superior resolution and straightforward method of sample preparation. It is proposed that FrSCA could be applied to organic compounds by rotational-echo double resonance (REDOR) spectroscopy, a widely used method for measuring heteronuclear distances.

Nanoparticle rings can be formed by two different mechanisms: dipole-directed self-assembly and evaporation-driven hole formation in viscous wetting layers. The two mechanisms are disparate as they may prove to be synergistic in the assembly of well-defined rings from larger magnetic nanoparticles, whose cooperative dipolar interactions might otherwise produce extended chains.

The assembly of dithiocarbamate (DTC) ligands on Au surfaces by exposure to carbon disulfide and secondary amine is described. It is shown that a variety of secondary amines can condense with carbodithioate (CS2) onto Au surfaces at room temperature without additional base to form ligands, which are stable in acidic and basic aqueous environments and in the presence of competing surfactants.

Conditions allowing large gold particles to self-organize at air-water interfaces into monoparticular films are described.