Noel S. Hush

Bio: Noel S. Hush is an academic researcher from University of Sydney. The author has contributed to research in topics: Valence (chemistry) & Dipole. The author has an hindex of 56, co-authored 243 publications receiving 10722 citations. Previous affiliations of Noel S. Hush include University of Rome Tor Vergata & MacDiarmid Institute for Advanced Materials and Nanotechnology.

Long-range photoinduced through-bond electron transfer and radiative recombination via rigid nonconjugated bridges: distance and solvent dependence

Abstract: A series of molecules 1 was synthesized containing a 1,4-dimethoxynaphthalene donor (D) an a 1,1-dicyanoethylene acceptor (a) interconnected by five different, rigid, nonconjugated bridges. The length of the bridges varies with increments of two sigma-bonds from four in 1(4) to 12 sigma-bonds in 1(12), to provide donor-acceptor center-to-center separations (R/sub c/) ranging from 7.0-14.9 A. In solvents of medium and high polarity, excitation of the donor D is followed by rapid intramolecular electron transfer. The rate constant (k/sub et/) shows only small dependence upon the solvent polarity (a factor of 2-3 between benzene and acetonitrile, for example) but decreases with increasing separation ranging from >10/sup 11/ s/sup -1/ for a four-bond separation to approx. =4 x 10/sup 8/ s/sup -1/ for a 12-bond separation. In saturated hydrocarbon solvents photoinduced electron transfer is not observed for 10 and 12-bond separations, while it is not significantly decreased for the shorter homologues. Therefore the absence of electron transfer at 10- and 12-bond separations in saturated hydrocarbon solvents is attributed to a thermodynamic rather than to a kinetic effect. In solvents where electron transfer is thermodynamically feasible, its rate is considerably greater than that found from various other experimental studies where either different bridgesmore » were used or intermolecular electron transfer was studied. Through-bond interaction involving sigma/..pi.. interaction between the bridge and the donor-acceptor pair is proposed to explain the very high electron transfer rates observed in 1; this is qualitatively correlated with independent information about this coupling derived from both theory and experiment (photoelectron spectroscopy).« less

Formalism, analytical model, and a priori Green's-function-based calculations of the current-voltage characteristics of molecular wires

Abstract: Various Green’s-function-based formalisms which express the current I as a function of applied voltage V for an electrode–molecule–electrode assembly are compared and contrasted. The analytical solution for conduction through a Huckel (tight binding) chain molecule is examined and only one of these formalisms is shown to predict the known conductivity of a one-dimensional metallic wire. Also, from this solution we extract the counter-intuitive result that the imaginary component of the self-energy produces a shift in the voltage at which molecular resonances occur, and complete analytical descriptions are provided of the conductivity through one-atom and two-atom bridges. A method is presented by which a priori calculations could be performed, and this is examined using extended-Huckel calculations for two gold electrodes spanned by the dithioquinone dianion. A key feature of this is the use of known bulk-electrode properties to model the electrode surface rather than the variety of more approximate schemes which are in current use. These other schemes are shown to be qualitatively realistic but not sufficiently reliable for use in quantitative calculations. We show that in such calculations it is very important to obtain accurate estimates of both the molecule–electrode coupling strength and the location of the electrode’s Fermi energies with respect to the molecular state energies.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Quantum mechanical continuum solvation models.

Abstract: 6.2.2. Definition of Effective Properties 3064 6.3. Response Properties to Magnetic Fields 3066 6.3.1. Nuclear Shielding 3066 6.3.2. Indirect Spin−Spin Coupling 3067 6.3.3. EPR Parameters 3068 6.4. Properties of Chiral Systems 3069 6.4.1. Electronic Circular Dichroism (ECD) 3069 6.4.2. Optical Rotation (OR) 3069 6.4.3. VCD and VROA 3070 7. Continuum and Discrete Models 3071 7.1. Continuum Methods within MD and MC Simulations 3072