bluuebunny/crossref_metadata_2025 huggingface dataset:
Trends in western North Pacific tropical cyclone intensity
Authors: Wu Man‐Chi , Yeung Kai‐Hing , Chang Wen‐Lam
Published: December 2006

Using the tropical cyclone best track data from the U.S. Department of Defense's Joint Typhoon Warning Center (JTWC), Webster et al. [2005] found that between the two consecutive 15‐year periods of 1975–1989 and 1990‐2004, the percentage of typhoons in the western North Pacific meeting the definition of categories 4 and 5 on the Saffir‐Simpson Hurricane Scale has increased from 25% to 41% of all typhoons in that ocean basin.

However, an analysis of the best track data from the Regional Specialized Meteorological Centre (RSMC) Tokyo (Japan) as well as that of the Hong Kong Observatory (HKO; Hong Kong, China) indicates that, in contrast to Webster et al.'s [2005] findings, there was no increase in western North Pacific category 4–5 typhoon activity. Furthermore, neither RSMC‐Tokyo nor HKO best track data suggest an increase in western North Pacific tropical cyclone destructiveness as measured by the potential destructive index (PDI).
Arctic continues warming trend
Authors: Zielinski Sarah
Published: December 2006

The Arctic continued to show signs of warming in 2001–2005, according to a report authored by a group of international scientists and released on 16 November by the U.S. National Oceanic and Atmospheric Administration. These signs include a continued reduction in the extent of sea ice, which reached a record minimum in 2005. An increase in the northward transport of ocean heat through the Bering Strait in 2001–2004 is believed to be a factor in the loss of sea ice. The State of the Arctic Report also documented increasing permafrost temperatures and increasing greenness of tundra vegetation.
Supporting members and friends
Authors: Anonymous
Published: December 2006

The following list gratefully acknowledges annual gifts of $100 or more and cumulative giving of $5,000 or more. The 1919 Society ($100,000 or more) and Benefactors ($5,000–$99,999) recognize single major gifts and cumulative contributions. Three circles acknowledge annual giving: President's Circle ($1,000 or more), Leadership Circle ($200–$999), and Supporters Circle ($100–$199). Supporting Life Members, who contribute a one‐time gift of $1,200 in addition to lifetime dues, are among our most loyal supporters.
Si and C interactions in the world ocean: Importance of ecological processes and implications for the role of diatoms in the biological pump
Authors: Ragueneau Olivier , Schultes Sabine , Bidle Kay , Claquin Pascal , Moriceau Brivaëla
Published: December 2006

Diatoms play a major role in carbon export from surface waters, but their role in the transport of carbon to the deep sea has been questioned by global analyses of sediment trap fluxes which suggest that organic carbon fluxes and transfer efficiencies through the mesopelagic are tightly correlated with CaCO3 (Klaas and Archer, 2002; François et al., 2002). Here we explore the role of diatoms in the biological pump through a study of Si and C interactions from the molecular to the global scale. Recent findings on molecular interactions between Si and C are reviewed. The roles of bacteria, grazers and aggregation are explored and combined, to account for the extent of Si and C decoupling between surface waters and 1000 m, observed to be very homogeneous in different biogeochemical provinces of the ocean. It is suggested that the mesopelagic food web plays a crucial role in this homogeneity: Sites of high export are also sites where diatom C is being either remineralized or channeled toward the long‐lived carbon pool most efficiently in the mesopelagic zone. The amount of carbon participating in the biological pump but not collected in sediment traps remains to be explored. It is also demonstrated that statistical analyses performed at global scales hide spatial variability in carrying coefficients, indicating a clear need to understand the mechanisms that control spatial and temporal variations in the relative importance of ballast minerals and other export mechanisms such as particle dynamics.
In defense of Milankovitch
Authors: Roe Gerard
Published: December 2006

The Milankovitch hypothesis is widely held to be one of the cornerstones of climate science. Surprisingly, the hypothesis remains not clearly defined despite an extensive body of research on the link between global ice volume and insolation changes arising from variations in the Earth's orbit. In this paper, a specific hypothesis is formulated. Basic physical arguments are used to show that, rather than focusing on the absolute global ice volume, it is much more informative to consider the time rate of change of global ice volume. This simple and dynamically‐logical change in perspective is used to show that the available records support a direct, zero‐lag, antiphased relationship between the rate of change of global ice volume and summertime insolation in the northern high latitudes. Furthermore, variations in atmospheric CO2 appear to lag the rate of change of global ice volume. This implies only a secondary role for CO2 – variations in which produce a weaker radiative forcing than the orbitally‐induced changes in summertime insolation – in driving changes in global ice volume.
Spatial structure of ionospheric convection velocities in regions of open and closed magnetic field topology
Authors: Abel G. A. , Freeman M. P. , Chisham G.
Published: December 2006

We present a spatial structure function analysis of ionospheric velocity, measured by the Halley Super Dual Auroral Radar Network (SuperDARN) radar over five years. We show evidence for scale‐free velocity fluctuations for separations from 45 km to ∼1000 km. For larger separations a deviation from scale‐free structure is seen that we interpret as the influence of the global convection pattern. We find evidence for scale‐free structure in regions of both open and closed field line topology, though with different power‐law exponents. The measured power‐law exponents poleward and equatorward of the open‐closed field line boundary are 0.31 and 0.39 respectively. We propose that the scale‐free spatial structure of ionospheric velocity fluctuations on open magnetic field lines is a reflection of the spatial structure of the solar wind and the scale‐free spatial structure of ionospheric velocity fluctuations on closed magnetic field lines is dictated by the internal dynamics of the magnetosphere‐ionosphere system.
Three‐dimensional velocity structure in the Bungo Channel and Shikoku area, Japan, and its relationship to low‐frequency earthquakes
Authors: Nugraha Andri Dian , Mori Jim
Published: December 2006

We used a tomographic inversion to determine P and S wave structures in the western Shikoku and Bungo Channel region, for comparison with the locations of low‐frequency earthquakes. The velocity model clearly images the high velocity subducting slab and we can see the spatial relation to the low‐frequency earthquakes. Under western Shikoku the low‐frequency earthquakes occur at depths close to the plate interface, but under the adjacent Bungo Channel region to the west, there is a clear depth separation. Our interpretation is that the low‐frequency events are occurring in a region of high Vp/Vs that is located above the subducting slab. The depth separation above the plate seems to vary depending on the region.
Timescales and development of groundwater pollution by nitrate in drinking water wells of the Jahna‐Aue, Saxonia, Germany
Authors: Osenbrück Karsten , Fiedler Stefan , Knöller Kay , Weise Stephan M. , Sültenfuß Jürgen , Oster Harald , Strauch Gerhard
Published: December 2006

Nitrate pollution from agricultural activities often persistently affects groundwater quality due to long residence times in the vadose and saturated zone. In this study we used a lumped parameter approach to estimate the residence time of groundwater and nitrate from the agriculturally used Jahna‐Aue drinking water catchment in Saxonia, Germany. Inverse modeling of measured concentrations of tritium and tritiogenic 3He revealed consistent mean residence times between 25 and 50 years for the young, nitrate‐rich groundwater component, and high contributions (>75%) of an old, tracer‐free, and nitrate‐poor groundwater. The obtained age distributions are in accordance with the complex hydrogeological situation of the investigated catchment, suggesting that the shallow and therefore most vulnerable part of the aquifer is not connected to the production wells. High residence times are supported by low concentrations of CFCs and by radiogenic 4He as an independent age indicator. CFC concentrations only yield lower age limits due to identified problems with CFC contamination. Using the tracer‐calibrated age distributions, future nitrate concentrations in the production wells most probably will remain below the drinking water limit because of the high dilution with old, nitrate‐poor groundwater. Deterioration of the groundwater quality with respect to nitrate may occur if the groundwater pumping regime is changed so that the fraction of the younger, nitrate‐bearing water is increased.
Absorption-induced stimulated scattering of second sound in a superfluid
Authors: Pushkina N. I.
Published: December 2006

A new type of wave interaction for hydrodynamics—absorption-induced stimulated scattering—is considered. The present treatment is particularized to the case of stimulated scattering of second sound in a superfluid. If two waves—an intense pump wave and a signal wave—are propagating in a medium, the power released in the medium, which is proportional to the square modulus of the total field, contains an interference term at the difference frequency of the pump and signal waves. Since the properties of the medium depend on temperature, the temperature inhomogeneities arising at the difference frequency cause scattering of the pump wave, resulting in a field which is resonant for the signal wave. That field is proportional to the absorption coefficient and the intensity of the pump wave. At low intensities of the pump wave such scattering leads to partial compensation of the dissipation of the signal wave, and with increasing intensity of the pump wave it can lead to amplification of the signal wave. This means that stimulated scattering can arise. Analysis of the experimental data suggests that the threshold intensity of this stimulated scattering can be a real experimental quantity.
Electronic structure and magnetic properties of RNi5−xCux alloys (R=Y, La, Ce)
Authors: Grechnev G. E. , Logosha A. V. , Svechkarev I. V. , Kuchin A. G. , Kulikov Yu. A. , Korzhavyi P. A. , Eriksson O.
Published: December 2006

A study is made of the electronic structure and magnetic properties of RN5−xCux alloys (R=Y, La, Ce). The influence of substitution of nickel by copper on the features of the band structure and behavior of the magnetic susceptibility of these alloys is investigated. An analysis is made of the electronic states and interactions responsible for the magnetic properties of RNi5−xCux alloys.
Experimental observation of electromagnetic beam waves
Authors: Burma N. G. , Petruishin A. I. , Ryabukha N. A. , Fil V. D.
Published: December 2006

The electromagnetic transparency of high-purity gallium single crystals at zero magnetic field is investigated at temperatures of 1.7–4.2K. Under conditions of strong temporal dispersion beam electromagnetic waves are observed which are due to electrons from the flattenings of the Fermi surface. The velocities, damping, moduli, and initial phases of the excitation coefficients are measured and the frequency dependence of the damping and the dependence of the phase velocity on the relaxation time are obtained. Beam waves, unlike ballistic (quasiwave) transport of electromagnetic field, are characterized by the presence of Landau damping and significant decrease of the phase velocity with decreasing relaxation time.
Nonequilibrium plasmons and transport properties of a double-junction quantum wire
Authors: Kim J. U. , Choi Mahn-Soo , Krive I. V. , Kinaret J. M.
Published: December 2006

We study theoretically the current-voltage characteristics, shot noise, and full counting statistics of a quantum wire double-barrier structure. We model each wire segment by a spinless Luttinger liquid. Within the sequential tunneling approach, we describe the system’s dynamics using a master equation. We show that at finite bias the nonequilibrium distribution of plasmons in the central wire segment leads to increased average current, enhanced shot noise, and full counting statistics corresponding to a super-Poissonian process. These effects are particularly pronounced in the strong interaction regime, while in the noninteracting case we recover results obtained earlier using detailed-balance arguments.
Characterization of ZnSe nanocrystals grown by vapor phase epitaxy
Authors: Tishchenko V. V. , Kovalenko A. V.
Published: December 2006

This paper reports the application of scanning electron microscopy, x-ray diffraction, and photoluminescence techniques for characterization of ZnSe nanocrystals grown on GaAs (100) substrate from the vapor phase. The characterization techniques used show evidence for the coexistence of two sets of nanocrystals with rather different characteristic sizes. In addition, the lowest energy levels of spherically shaped nanocrystals are calculated in the framework of the effective-mass approximation and compared with photoluminescence data.
Electron diffraction study of two-component clusters Ar–Kr: Features of the nucleation, growth mechanisms, and structural states
Authors: Danylchenko O. G. , Kovalenko S. I. , Samovarov V. N.
Published: December 2006

The structure and growth processes of clusters formed in adiabatically expanding supersonic jets of gaseous mixtures of rare gases are investigated for the first time. Ar–Kr mixtures containing 0.1, 0.5, 2.5, and 20% Kr atoms are studied at temperatures and pressures of the gaseous mixtures at the nozzle entrance T0=100 and 120K and P0=0.15–2.5atm. The experiments give a number of results that shed light on the picture of cluster formation in Ar–Kr gaseous mixtures. It is established that the mechanisms of cluster formation depend substantially on the krypton impurity concentration and the temperature of the gaseous mixture at the nozzle entrance. The evolution of the character of the cluster formation, from homogeneous to heterogeneous, is traced. The intensification of rare-gas cluster growth by an impurity is revealed for the first time, and the concentration dependence of the transition from a process of formation of solid solutions to the formation of clusters containing only impurity krypton is traced.
Anisotropy of the temperature dependence of the lattice parameters of EuBa2Cu3O7−d in the quasiharmonic limit
Authors: Eremenko V. V. , Gospodarev I. A. , Ibulaev V. V. , Sirenko V. A. , Feodosev S. B. , Shvedun M. Yu.
Published: December 2006

An x-ray diffraction analysis of the compound EuBa2Cu3O7−δ is carried out in the temperature range 20–300K. At all temperatures of measurement the structure is described in the orthorhombic system. Nonmonotonic growth of the crystal lattice parameter c with decreasing temperature is observed in the interval 150–20K, and substantial features of the temperature dependence of the coefficient of linear thermal expansion appear below the Debye temperature. The results of the experiment are in complete agreement with the conclusions of a microscopic treatment of the vibrations of the atoms of the BaO and europium layers and also the Cu–O chains.
Growth and multiferroic properties of hexagonal HoMnO3 films
Authors: Kim J.-W. , Schultz L. , Dörr K. , Van Aken B. B. , Fiebig M.
Published: January 2007

Hexagonal, twin-free HoMnO3 (0001) films of 25–240nm thickness were grown epitaxially on Y2O3:ZrO2(111) substrates using pulsed laser deposition. Ferroelectric polar order and Mn3+ antiferromagnetism were observed by optical second harmonic generation. Magnetization data reveal Ho3+ ordering which is, with subtle deviations, similar to that of bulk crystals. However, three phase transitions below 6K and thermal hysteresis of magnetization at T<42K were detected.
Is There a Single 'Best Pool' of Commercial Reagents to Use in Combinatorial Library Design to Conform to a Desired Product–Property Profile?
Authors: Truchon Jean-François , Bayly Christopher I.
Published: December 2006

A novel computer algorithm for library design in combinatorial chemistry, GLARE (Global Library Assessment of Reagent), is used to select an optimal subset of reagents in two related libraries according to the Lipinski rule of five applied to the products. The optimized libraries show excellent compliance with the desired profiles although the original huge libraries do not. Then we show, using ten different virtual libraries, that (a) a relatively small fraction of commercially available reagents is of general use in drug/lead-like combinatorial chemistry and (b) that between 10 and 20% of the reagents are not of general use but specific to a library. This demonstrates the utility of using a product-based reagent selection method.
Conformational Boosting
Authors: Agrafiotis Dimitris K. , Gibbs Alan , Zhu Fangqiang , Izrailev Sergei , Martin Eric
Published: December 2006

Stochastic proximity embedding (SPE) is a novel self-organizing algorithm for sampling conformational space using geometric constraints derived from the molecular connectivity table. Here, we describe a simple heuristic that can be used in conjunction with SPE to bias the conformational search towards more extended or compact conformations, and thus greatly expand the range of geometries sampled during the search. The method uses a boosting strategy to generate a series of conformations, each of which is at least as extended (or compact) as the previous one. The approach is compared to several popular conformational sampling techniques using a reference set of 59 bioactive ligands extracted from the Protein Data Bank, and is shown to be significantly more effective in sampling the full range of molecular radii, with the exception of the Catalyst program, which was equally effective.
Emergence and Self-Organization in Chemistry and Biology
Authors: Newth David , Finnigan John
Published: December 2006

Complex systems display two key properties that distinguish them from systems that are merely very, very complicated: emergence and self-organization. Emergence is the appearance of behaviour at system level that is not implicit in the properties of the system’s components; self-organization implies the increase of a system’s internal order without the imposition of external control. Competing definitions of emergence and self-organization have led to confusion. Here, we follow the idea proposed by Anderson, that emergence and self-organization are signalled by symmetry-breaking. In general, a steady-state configuration of matter must exhibit the same symmetries as the equations that govern its dynamics. However, while this might apply to the component parts of a system in isolation, the whole system might display less symmetry because of the interactions between its individual parts. Here, we will explore several systems where microscopic symmetry is broken by the interaction between the component parts of the system. These examples show that macroscopic symmetry-breaking is an important factor in the formation of system level order from chemical reactions through to the organization of ecosystems.
The Synthesis of Membrane Permeant Derivatives of myo-Inositol 1,4,5-Trisphosphate
Authors: Conway Stuart J. , Thuring Jan W. , Andreu Sylvain , Kvinlaug Brynn T. , Roderick H. Llewelyn , Bootman Martin D. , Holmes Andrew B.
Published: December 2006

In order to enable the study of the intracellular second messenger d-myo-inositol 1,4,5-trisphosphate (InsP3) and its receptors (InsP3Rs), it has been desirable to develop protected derivatives of InsP3 that are able to enter the cell, upon extracellular application. The subsequent removal of the lipophilic protecting groups, by intracellular enzymes, releases InsP3 and leads to the activation of InsP3Rs. Two syntheses of d-myo-inositol 1,4,5-trisphosphate hexakis(butyryloxymethyl) ester (d-InsP3/BM) and one of l-InsP3/BM are reported. It is demonstrated that extracellular application of the d-enantiomer results in Ca2+ release, which is thought to occur via InsP3Rs. Application of the l-enantiomer resulted in little Ca2+ release.
The Basic Strength of Formaldehyde
Authors: McTigue PT , Sime JM
Published: December 2006

The pKa of
protonated formaldehyde has been estimated as -4.2, using spectroscopic and
kinetic data obtained in concentrated acid solutions.
Methylsteroids. VIII. The Reaction of Methylmagnesium Iodide with Ketones derived from Lanosterol
Authors: Barnes CS , Beilby BD
Published: December 2006

A brief study has been made of the
reaction of methylmagnesium iodide with 38-acetoxylanostan-7,11-dione (I), 3β-acetoxylanost-8-en-7,11-dione
(VII), and lanostan-3-one (XII). Dehydration of the resulting alcohols has also
been examined.
The Fatty Acid Composition of Vernix caseosa
Authors: Downing DT
Published: December 2006

The fatty acids obtained on hydrolysis of
sebum from newly-born babies contained approximately equal amounts of saturated
and unsaturated fatty acids and 10% of α-hydroxyacids. Gas chromatographic
examination showed that the saturated fatty acids (C12 to C30)
contained 78% branched-chain and 22% normal compounds, while the unsaturated
acids (C12 to C32) contained 15% branched and 85% normal
compounds. The a-hydroxyacids (C10 to C26) contained 79%
branched-chain and 21% normal components and had little if any unsaturation.
The high proportion of branched-chain acids suggests that these are not likely
to be exogenous.
Studies in the Stereochemistry of Zinc(II). I. Derivatives of Bis(acetyl-acetonato)zinc(II)
Authors: Graddon DP , Weeden DG
Published: December 2006

The compound melting at 138� and for long
supposed to be anhydrous bis(acetylacetonato)zinc(II) is shown to be the
monohydrate. The anhydrous compound has also been obtained, melting at 152�;
and adducts are described with one and two molecules of pyridine or
4-methylpyridine, one molecule of 2-methylpyridine, and two molecules of
ammonia. Molecular weight determinations in benzene and triphenylmethane show
that with the exception of the anhydrous compound which is monomeric, the
predominant species in solution are five-coordinate. Differences in the
stereochemical behaviour of zinc in these compounds from the behaviour of
cobalt(II) and nickel(II) in corresponding compounds are interpreted in terms
of crystal-field stabilization of octahedral complexes of the latter ions.
The Alkaline Titration of Ovalbumin in the Presence of Copper(II)
Authors: Jennings AC
Published: December 2006

The alkaline titration of ovalbumin in the
presence of copper(II), together with the measurement of absorption spectra at
various pH-levels, showed the progressive displacement of protons from the
peptide bonds and increasing chelate formation with increasing pH. The possible
mechanism of bond formation and nature of the chelate species formed are
discussed. The results provide further evidence that a heterogeneous mixture of
chelate species is formed between copper(II) and ovalbumin in the biuret reaction.
Effects of alkyl groups on acidities and basicities in the gas phase. An ab initio molecular orbital study
Authors: Radom L
Published: December 2006

Ab initio molecular orbital
theory has been used to investigate the acidities and basicities of alcohols
(ROH), alkylamines (RNH2) and alkynes (RCCH) (R = Me, Et, isopropyl,
t-butyl). In all cases, the acidities and basicities increase in the order R =
Me < Et < Pri < But.
Analysis of the calculated charge distributions shows that alkyl groups can
donate or accept electrons on demand and that the larger alkyl groups examined
do this more effectively than the smaller ones.
The enthalpies of solution of ethanol, propan-1-ol, propan-2-ol and butan-1-ol in deuterium oxide
Authors: Hill DJT , Malar C
Published: December 2006

The enthalpy changes on
solution of the alcohols enthanol, propan-1-ol, propan-2-ol and butan-1-ol in
deuterium oxide have been measured at 283 and 298 K, and the enthalpy changes
on transfer of the alcohols from water to deuterium oxide have also been calculated.
The results have been compared qualitatively with data obtained by other
workers and also with data for other related solutes.
Synthesis of 9,10-dihydrophenanthrenes including orchinol methyl ether
Authors: Bowden BF , Read RW , Ritchie E , Taylor WC
Published: December 2006

Reduction of 2-phenylindole
gave the dihydro derivative which was hydrogenolysed to give bibenzyl-2-amine.
The latter was best converted into 9,10-dihydrophenanthrene by decomposition of
the derived azosulphone. Several methoxydihydrophenanthrenes, including
orchinol methyl ether, were prepared by this route. ��� Conversion of dihydrophenanthrenes into
phenanthrenes may be conveniently effected by benzylic bromination followed by
dehydrobromination.
The chemistry of 2,1-benzisothiazoles. VIII. Tautomerism of 2,1-Benzisothiazolin-3-one and the preparation of N- and O-alkylated derivatives
Authors: Davis M , Deady LW , Homfeld E , Pogany S
Published: December 2006

Both N-alkyl and O-alkyl
derivatives of 2,1-benzisothiazolin-3-one (1) have been prepared by unambiguous
syntheses. Comparison of ultraviolet spectra indicates that (1) exists in the
keto form rather than as its tautomer 2,1-benzisothiazol-3-ol (2). Alkylation
of the anion of (1) yields N-alkylated products.
Concerning the reported formation of 3,4,4-Triphenylisoxazoline from 1-aci-Nitro-1,2,2-triphenylpropane under acidic conditions. Acid catalysed fragmentation of secondary aci-Nitro compounds
Authors: Kazlauskas R , Pinhey JT
Published: December 2006

Treatment of
1-aci-nitro-1,2,2-triphenylpropane (1) with hydrochloric acid leads to the
formation of 3,5,5-triphenylisoxazoline (3), not 3,4,4-triphenylisoxazoline (2)
as previously reported. The route from (1) to (3) has been shown to involve a
fragmentation of the aci-nitro compound, similar to
the ?abnormal? Beckmann rearrangement of oximes, to give 1,1-diphenylethylene
and benzonitrile oxide, which then combine in a 1,3-dipolar addition.
Nitrones and oxaziridines. XIII. A convenient method for the oxidation of primary- and secondary-alkyl amines to carbonyl compounds
Authors: Black DSC , Blackman NA
Published: December 2006

Primary- and
secondary-alkyl amines have been converted in good yield into the related
carbonyl compounds by sequential conversion into isopropylidene imines and
3,3-dimethyloxaziridines, followed by acidic hydrolysis of the latter.
Intermediates need not be isolated.
Monoterpenes of Teucrium marum
Authors: Pagnoni UM , Pinetti A , Trave R , Garanti L
Published: December 2006

Four cyclopentanoid
monoterpenes were isolated from Teucrium marum; they are the two [(A) and (B)] C2-epimers
of a-(2-formyl-3-methylcyclopentyl)acrylaldehyde and
two new [(C) and (D)] isomeric unsaturated lactones. Structures were
established by spectral (u.v., i.r.,
N.M.R., m.s.) evidence and chemical transformations.
Synthesis of methyl 2-Oxotetralin-1-carboxylates
Authors: Oommen PK
Published: December 2006

The base-catalysed reaction
of dimethyl carbonate with 2-tetralones has been found to lead to the formation
of methyl 2-oxotetralin-1-carboxylates (1). This constitutes an excellent
method of synthesis of the title compounds. Thus the tetralone
(2b) on reaction with dimethyl carbonate and sodium hydride gave the keto ester
(lb) in 92% yield. The extent of enolization of these
tetralone esters was found to depend on the size of
the substituent in the C8 position.
Interactions of dyes with wool. Spectral and photochemical studies of fluorescent whitening agents
Authors: Leaver IH
Published: December 2006

A spectral study has been
made of the interactions of four types of fluorescent whitening agents with
wool. Fluorescence excitation and emission spectra have been measured in single
wool fibres, and are compared with the corresponding spectra in solution and in
polymer films. The polarity of the environment has a pronounced effect on the
fluorescence properties of the whiteners in solution, but generally has little
effect in rigid media. The emission spectra in wool are found to be strongly
influenced by the concentration of whitener in the fibre. This heterogeneity of
the fluorescence is attributed both to aggregation of the whitener and to
changes in the polarity of its micro-environment in the fibre. The results of
fluorescence depolarization studies indicate that electronic energy transfer
between whitener molecules occurs efficiently at the concentrations normally
used for whitening wool. Critical transfer distances and concentrations have
been determined for the various whiteners, and are compared with the values
predicted by Forster's theory of dipole-dipole transfer. The photochemical
behaviour of the fluorescent whiteners in wool has been examined, and the
effects of oxygen and water on the fading rates are discussed.
Nitration studies of 4-substituted toluenes, 5-substituted hemimellitenes and acetoxyprehnitene
Authors: Clemens AH , Hartshorn MP , Richards KE , Wright GJ
Published: December 2006

Product distributions are
reported for the nitration of 4-methoxy-, 4- bromo- and 4-acetoxy-toluenes, of
5-fluoro- and 5-acetamido- hemimellitenes, and of acetoxyprehnitene. A Hammett
p value for ipso nitration is estimated from competitive nitrations with a
series of 5-substituted hemimellitenes.
Thermal and photodimerization of Benzo[b]thiophen-3-carboxylic acid 1,1-Dioxide
Authors: Davies W , Ennis BC , Mahavera C , Porter QN
Published: December 2006

Benzo[b]thiophen-3-carboxylic
acid 1,1-dioxide is shown to undergo dimerization to a cyclobutane under the
influence both of ultraviolet light and of heat, whereas the corresponding
methyl ester is dimerized only by ultraviolet light.
The dimer is shown to be of the 'head-to- head' type, with trans stereochemistry
about the cyclobutane ring.
Methyleneketenes and methylenecarbenes. VII. Evidence for the pyrolytic generation of methyleneketene (propadienone)
Authors: Brown RFC , Eastwood FW , McMullen GL
Published: December 2006

Oxidation of 2,2,5-trimethyl-5-phenylseleno-1,3-dioxan-4,6-dione
with m-chloroperbenzoic acid in methylene chloride gives a solution containing
2,2-dimethylspiro[1,3-dioxan-5,2'-oxiran]-4,6-dione and the unstable
2,2-dimethyl-5-methylene-1,3-dioxan-4,6-dione, which forms stable adducts with
cyclohexadiene and cyclopentadiene. Flash vacuum pyrolysis of the
cyclopentadiene adduct over the temperature range 460- 570° and detection of
the components present in the pyrolysate by mass spectrometry showed that cyclopentadiene,
acetone, carbon dioxide and methyleneketene (CH2=C=C=O) are formed;
the last breaks down into acetylene and carbon monoxide at higher temperatures
(520-570°). Infrared measurements on the pyrolysis products kept at liquid
nitrogen temperature showed absorption near 2100 cm-1 which is
attributed to methyleneketene. Reaction of the pyrolysate with aniline vapour
or methanol vapour yielded acrylanilide and methyl acrylate respectively.
Pyrolysis in the absence of trapping agents gave a glassy solid on an uncooled
glass surface. This solid is considered to be formed by addition of methyleneketene
to 2,2-dimethyl-5-methylene-1,3-dioxan-4,6- dione. Methanolysis of the solid
and esterification with diazomethane gave dimethyl 2-methoxycarbonyl-4-methylenepentanedioate.
Contact angles and hysteresis, with some reference to flotation research
Authors: Wark IW
Published: December 2006

A technique used in
flotation research for contact angle measurements is recommended for wider use.
The effect of one aspect of surface roughness on the relative motion of
fluid/solid systems is discussed. The function of the water vapour present in
the gas phase adjacent to the line of triple contact is examined. A claim of
the Russian school of surface chemists is questioned, namely, that a discrete
film of water on the solid surface invariably dominates both hysteresis and
contact angle.
Reaction of 2,4,6-Triphenyl-3,4-dihydro-2H-1,2,4,5-tetrazin-1-yl with hydroquinone
Authors: Nishimura N , Itakura N
Published: December 2006

A kinetic study has been
made of the reaction between 2,4,6-triphenyl- 3,4-dihydro-2H-1,2,4,5-tetra
zin-1-yl and hydroquinone. The results showed that this reaction is reversible
and involves two steps. The activation energies for the forward and backward reactions
are 45.2 and 18.0 kJ mol-1, respectively.
Metal template reactions. X. Improved syntheses of 2,2'-(Ethane-1,2-diyldiimino) bisbenzaldehyde and 2,2'-(Propane-1,3-diyl-diimino)bisbenzaldehyde
Authors: Black DSC , Vanderzalm CHB , Hartshorn AJ
Published: December 2006

2,2'-(Propane-1,3-diyldiimino)bisbenzaldehyde
(2) has been synthesized by a high-yielding route involving the alkylation of
the isatin anion with 1,3-dibromopropane. 2,2'-(Ethane-1,2-diyldiimino)-bisbenzaldehyde
(1) can be synthesized most effectively by a route involving initial acylation
of methyl anthranilate with oxalyl chloride. Subsequent reductive and oxidative
transformations are then carried out in each case.
The reactions of some diynes with (C5H5)Co(CO)2 and Fe(CO)5: Inter- or Intra-molecular cyclizations?
Authors: Dickson RS , Mok C , Connor G
Published: December 2006

The reactions of several
diynes MeC≡C(CH2)nC≡CMe,
n = 2-4, with (η- C5H5)Co(CO)2 and Fe(CO)5
have been compared. A p-benzoquinone complex, (η-C5H5)Co[(C8H10)2(CO)2],
and three isomers of the cyclopentadienone complex, (η-C5H5)Co[(C8H10)2CO],
are formed in the reaction of (η- C5H5)Co(CO)2
with octa-2,6-diyne. In each complex, the ligand is formed by intermolecular cyclization
of two diynes with inclusion of CO. The corresponding reactions with
nona-2,7-diyne and deca-2,8-diyne give complexes (η-C5H5)Co[(C9H12)CO]
and (C5H5)Co[(C10H14)CO] in which a
bicyclic cyclopentadienone has been formed by intramolecular condensation of
the diyne. Intramolecular cyclization is also achieved when all three diynes
are treated with Fe(CO)5. The reactions with octa-
2,6-diyne and deca-2,8-diyne give metallodiene complexes, Fe2(CO)6(diyne),
in which the ferracyclopentadiene ring is fused to either a 4- or 6-membered
ring. With nona-2,7-diyne, a cyclopentadienone complex of formula Fe(CO)3[(C10H14)CO]
is isolated. In the reactions with Fe(CO)5,organic products of the
type (diyne)2, (diyne)3 and [(diyne)CO]2 are
also isolated.
Electron impact studies. CXVIII. An ion cyclotron resonance study of the reactivity of negative ions derived from ethenetetracarbonitrile. Anionic polymerization in the gas phase
Authors: Bowie JH
Published: December 2006

.The [M·–l CN·I- species from ethenetetracarbonitrile (tetracyanoethylene) reacts with neutral ethene-
tetracarbonitrile to give the stable adduct C11N7-. The decomposing form of this adduct eliminates
C2N2 to produce C,9N5- which may react with ethenetetracarbonitrile to yield C15N,9-. Analogous
anionic polymerization reactions yield a number of detectable peaks in the i.c.r. spectrum of tetra-
cyanoethylene, with the structures of the ions possibly corresponding to a.
Diagram
Polymerization of this type can also be initiated by other nucleophiles including Cl-, Br-, I-
and CF3CO2-.
An unusual caged oxetan formed by intramolecular photocyclization onto the carbonyl group of a polyalicyclic enedione
Authors: Warrener RN , McCay IW , Paddon-Row MN
Published: December 2006

p-Benzoquinone reacts with
1,4-dimethyl-2,3-diphenylcyclopentadiene and the similarly substituted cyclopentadienone
to form exclusively the endo adducts (12) and (9) respectively.
Photocyclization of these adducts in the solid state yields the respective cyclobutyl
photocage compounds (10) and (13).Photolysis of the dienone adduct (9) in
solution yields an unusual oxetan product (14) resulting from cyclization
between a carbonyl group of the enedione and the proximate olefinic π-centre,
as well as the normal cage product (10).
Stereospecific reactions of cis- and trans-3-Aminochroman-4-ols
Authors: Lap BV , Williams LR
Published: December 2006

Stereospecific reactions of
epimeric 3-amino-6-methylchroman-4-ols (1 and 2; R = Me) have provided chemical
evidence for their configuration and have led us to reverse the configurations
that we had assigned previously to the 6-bromo analogues on the basis of N.M.R.
data. ��� The 2-chloro-N-(4-hydroxy-6-methylchroman-3-yl)acetamides
(3) and (4) were treated with potassium hydroxide in ethanol in an attempt to
effect ring closure. The cis-chloroacetamide (4) gave a cyclic amide (5) while
the trans-chloroacetamide (3) reacted with solvent to form the trans-3-ethoxyacetamidochroman-4-ol
(6). ��� The configurations of the amino alcohols
were confirmed by a study of their reactions with nitrous acid where
deamination of the cis-amino alcohol gave the chroman-4-one (9) while the
trans-amino alcohol gave a trans-diol (10) by an epoxide intermediate.
Cyano esters and malononitriles. V. Cyano(fluorenyl)acetic esters, hydroxy nitriles and benzimidazolylacetonitriles
Authors: Latif N , Mishriky N , Hammad M
Published: December 2006

In contrast to the
analogous ylidenemalononitriles, it is found that
xanthen-, thioxanthen- and fluoren-9-ylidene cyanoacetates react with
organomagnesium halides to give 1,4-adducts regardless of the nature of the
Grignard reagent and its steric requirements. Apparently the reaction proceeds
through the intermediate formation of a cyclic transition state of lower energy
in the case of cyano esters than in the case of malononitriles. ��� The fluorenyl cyano esters (2b-e,g) react
with o-phenylenediamine at 240� affording the benz-imidazolyl(fluorenyl)acetonitriles
(10a-e), whereas, at lower temperature, the intermediate cyano anilides (11a-e)
are obtained which cyclize readily to the corresponding benzimidazoles.
Reactive lignin intermediates. VI. Oxidation and coupling of isoeugenol with a quinone methide
Authors: Leary G , Thomas W
Published: December 2006

Isoeugenol(1b) was
oxidatively coupled by the quinone methide 2,6-di-t-
butyl-4-methylenecyclohexa-2,5-dienone (4a). A simple isoeugenol- quinone
methide addition product was not observed but a 2 : 1 isoeugenol quinone
methide adduct was isolated. It is suggested that α- α links may
occur in lignin.
Potential Antimalarials. VI. Mannich-Bases Derived From 4-[7′-Bromo(and Chloro)-1′,5′-Naphthyridin-4′-Ylamino]Phenols and 4-(7′-Trifluoromethylquinolin-4′-Ylamino)Phenol
Authors: Barlin GB , Tan WL
Published: December 2006

Eleven di-Mannich bases derived from 4-[7′-bromo(and chloro )-1′,5′-naphthyridin-4′-ylamino]phenols and 4-(7′-trifluoromethylquinolin-4′- ylamino )phenol have been prepared. Each of these compounds showed very good antimalarial activity w en injected intraperitoneally in a single dose of 50-100 mg/kg to mice infected with Plasmodium vinckei vinckei.
Studies of Australian Soft Corals .XXXVI. The Isolation and Structure Determination of 11 Calamenene-Based Sesquiterpenes From Lemnalia-Cervicornis (Coelenterata, Octocorallia, Alcyonacea)
Authors: Bowden BF , Coll JC , Engelhardt LM , Tapiolas DM , White AH
Published: December 2006

The soft coral Lemnalia cervicornis May 1898 has afforded 13 novel sesquiterpenoid metabolites. The majority were derivatives of calamenen-7-ol and the structures were deduced by 1H
and 13C n.m.r . spectroscopy. Absolute stereochemistry of compounds (3)-(13) was determined by chemical correlation with 7-hydroxycalamenen-3-one (3) for which an X-ray structure determination of its 7-p-bromobenzoyl derivative is reported. Two minor metabolites (15) and (16) were not aromatic, but were structurally related to the algal metabolite zonarene (21) for which absolute stereochemistry was available.
Ion Ion Solvent Interactions in Solution .X. Group-2 Perchlorates in Water
Authors: James DW , Cutler PG
Published: December 2006

Solutions of Mg(ClO4)2, Ca(ClO4)2 and Sr (ClO4)2 have been studied at a variety of concentrations up to saturation by means of infrared absorption, Raman scattering and multinuclear n.m.r. spectroscopy. For solutions of Mg(ClO4)2 there was little ion association up to saturation but for the other two salts association to both solvent shared anion- cation complexes and contact anion-cation complexes was identified. The nature of the association process was probed by using line broadening for the quadrupolar nuclei 17O, 35Cl and 43Ca . The extent of association to solvent shared anion-cation complexes was found to increase in the series Mg2+ < Ca2+ < Sr2+.
Influence of Phenyl Substituents on Diamagnetic Cobalt(III) Dithiocarbamate Complexes
Authors: Healy PC , Hanna JV , Duffy NV , Skelton BW , White AH
Published: December 2006

Single-crystal X-ray structural determinations have been recorded at c.295 K for the tris ( dithiocarbamato )cobalt(III) compounds [Co(S2CNMePh)3] and [Co(S2CNPh2)3]. [Co(S2CNMePh)3] crystallizes in space group P21/a with a 25.207(6), b 12.778(2), c 9.497(2)Ǻ, β 116.40(2)°. [Co(S2CNPh2)3] crystallizes in space group Pī with a 14.979(6), b 13.169(4), c 10.683(3)Ǻ, α 71.53(3),β 88.15(3),γ 82.35(3)°. The structures were refined to residuals of 0.039 and 0.062 for 2184 and 4068 'observed' reflections respectively. The cobalt-59 n.m.r. chemical shift of the sparingly soluble diphenyl compound is found to be 6450 ppm downfield from K3Co(CN)6, compared with 6660 ppm for the methyl phenyl compound and 6830 ppm for the non-phenyl-substituted dimethyl compound, a result reflecting increase in the ligand -field strengths of the ligands in this series of compounds in the order Me2 < Me Ph < Ph2. Average geometric parameters (Ǻ) are: methyl phenyl, Co-S 2.270(6), C-S 1.699(6), C-N 1.341(9), S…S 2.803(2), N-Cphenyl 1.446(5), N-Cmethyl 1.45(1); diphenyl, Co-S 2.267(8), C-S 1.699(4), C-N 1.335(4), S…S 2.805(2), N-Cphenyl 1.449(6). Solid-state carbon-13 chemical shifts for thecarbon atom of the NCS2 fragment are 204, 207 and 210 ppm for [Co(S2CNMe2)3], [Co(S2CNMePh)3] and [Co(S2CNPh2)3] respectively. By comparison, the carbon-13 chemical shifts for cobalt complexes with saturated hydrocarbon substituents which span the range of ligand -field strengths do not show the same systematic trends: [Co(S2CN(CH2)4)3], 201 ppm ; [Co(S2CNEt2)3], 204 ppm ; and [Co(S2CNPri2)3], 204 ppm , [Co(S2CN(CH2Ph)2)3], 207 ppm . For the unsaturated hydrocarbon system, [Co(S2CN(CH)4)3], this value is 211 ppm . These results correspond closely to solution carbon-13 data and constitute good evidence that the ligand substituent effects in the compounds are similar in the two states. The increase in ligand -field strength with phenyl substituent is rationalized in terms of a combination of steric and electronic effects.
Nitridomolybdenum Complexes of Tris(3,5-dimethylpyrazol-1-yl)Hydroborate and the X-Ray Crystal-Structure of {HB(3,5-Me2C3N2H)3)MoN(N3)2
Authors: Young CG , Janos F , Bruck MA , Wexler PA , Enemark JH
Published: December 2006

The reaction of (NEt4)2[MoNCl5] and K{HB(Me2pz)3}[HB(Me2pz)3- = tris (3,5- dimethylpyrazol-1-yl) hydroborate anion] produces both purple, diamagnetic {HB(Me2pz)3}MoNCl2 (1) and yellow, paramagnetic Net4 [{HB(Me2pz)3}MoNCl2] (2) (e.s.r.: {g} 1.961, {a}(95Mo) 57×10-4 cm-1), which have been separately isolated under different conditions. In contrast, the reaction of [ MoN (N3)4]- with Na{HB(Me2pz)3} results in the exclusive formation of red {HB(Me2pz)3} MoN (N3)2 (3). Crystals of (3) are monoclinic and belong to space group P21/n with a 16.440(2), b 8.787(2), c 16.754(2) Ǻ,β 112.47(1)°, V 2236.4 Ǻ3, and Z 4. The structure was solved by Patterson and Fourier methods, followed by least-squares refinement, using 3208 reflections, to a conventional R value of 0.032 ( Rw 0.047). In the distorted octahedral complex the molybdenum(VI) atom is coordinated by a facial HB(Me2pz)3- ligand , a terminal nitrido ligand with a Mo-N bond distance of 1.646(4)Ǻ, and two azide ligands. All complexes have been characterized by elemental analysis, infrared, 1H n.m.r. or e.s.r. spectroscopy, and mass spectrometry. Improved syntheses for the starting materials (NEt4)2 [MoNCl5] and (NEt4)2 [MoNCl4] are also reported.
Reduction of Vicinal Dihalides. I. The Electrochemical Reduction of meso and (±)-1,2-Dibromo-1,2-diphenylethane
Authors: Fawell P , Avraamides J , Hefter G
Published: December 2006

The mechanism of the electrochemical dehalogenation of organic vicinal dihalides has been examined in acetonitrile by using meso- and (�)-1,2-dibromo-1,2-diphenylethane. Reduction potentials and product distributions obtained from the isomeric dibromides could not be accommodated within a mechanism involving a concerted addition of two electrons. However, these results can be explained by a stepwise addition of electrons, allowing the possibility of bond rotation at an intermediate stage. The product distributions obtained from the reduction of the (�)- dibromide were found to be potential-dependent, a result not previously observed for this compound, but consistent with a stepwise mechanism.
A Convenient Reagent for the Intermolecular Coupling of Aldehydes and Ketones to Form Olefins
Authors: Carroll AR , Taylor WC
Published: December 2006

When aldehydes or ketones are treated with titanium tetrachloride and amalgamated magnesium turnings in tetrahydrofuran at 0° for 2 h and subsequently under reflux for 24 h, reductive coupling occurs to give olefin in high yield. The optimum ratio of carbonyl substrate to titanium reagent was found to be 1 : 4. Examples of symmetrical and mixed couplings are given. Intramolecular coupling was not successful.
Manganese(III) Acetate-Induced Formation of a Fused, Chloro-Substituted β-Lactam Derivative From a Chloroacetamide
Authors: Bremner JB , Jaturonrusmee W
Published: December 2006

Reaction of 1-chloroacetyl-5-methoxy-2,3-dihydro-1H-dibenzo[de,h]quinoline (1) with manganese(III) acetate in acetic acid at 50° gave the novel fused spiro derivative 11-chloro-4-methoxy-1,2-dihydro-6H-azeto[2,1-f]dibenzo[de,h]quinoline-6,12(11H)-dione (6) in 21% yield, together with 5-methoxy-7H-dibenzo[de,h]quinolin-7-one (3), 5-methoxy-2,3-dihydro-7H-dibenzo[de,h]quinolin-7-one (4), and 1- chloroacetyl-5-methoxy-2,3-dihydro-1H-dibenzo[de,h]-quinolin-7-yl ethanoate (5) in 1, 3 and 44% yields respectively. Compound (5) was shown to be a precursor of (3), (4) and (6).
The Synthesis of Some Octenoses as Potential Precursors to Lincosamine, a Derived Portion of the Antibiotic Lincomycin
Authors: Stick RV , Tilbrook DMG
Published: December 2006

Methyl (E)-2,3-di-O-benzyl-6,7,8-trideoxy-α-D-galacto-oct-6-enopyranoside, a potential precursor to lincosamine, has been prepared from both methyl α-D-galactopyranoside and methyl α-D-glucopyranoside, with the required inversion at C4 in the latter sequence being effected by a conventional oxidation-reduction. As well, (E)-6,7-dideoxy-1,2: 3,4-di-O-isopropylidene-α-D-galacto-oct-6-enose and (E)- and (Z)-6,7,8- trideoxy-1,2:3,4-di-O-isopropylidene-α-D-galacto-oct-6-enose have been prepared from 1,2: 3,4-di-O-isopropylidene-α-D-galactose.
Electrolytes in Micropores
Authors: Vlachy V , Haymet ADJ
Published: December 2006

We review recent progress in the theory of electrolytes inside cylindrical micropores. Specific predictions for the spatial distribution of counter ions and co-ions are presented, and connections with existing experimental data are discussed. Potential applications to desalination methods are outlined.
Mixed-Halide Iodoargentate Anions: the Structural Characterization of (Ag3I3X)-, X= Cl, Br, I
Authors: Bowmaker GA , Effend y , Kildea JD , Skelton BW , White AH
Published: December 2006

Single-crystal structure determinations are recorded for [Ph3AsMe]+ [Ag3I3X]-, X= Cl , Br, I. The three complexes are isomorphous with their recently recorded [Cu3I4]- counterpart. They are also 'isomorphous' with the
recently recorded [Ph4P/As]+ [Ag3I4]-, crystallizing in a monoclinic P21/c
cell with a ≈ 12.5 , b ≈ 25.6, c ≈ 8.39Ǻ, β ≈
109°, Z=4 formula units. The anion is an infinite polymer with three distinct metal and four distinct halide sites; the mixed stoichiometry is achieved by displacement of the peripheral halide species.