bluuebunny/crossref_metadata_2025 huggingface dataset:
4,5-Seco-4,6-cyclosteroids. I. Structure and properties of the diol from reductive rearrangement of 6β-Bromo-4β,5-epoxy-5β-cholestan-3β-ol
Authors: Collins DJ , Hobbs JJ , Rawson RJ
Published: September 2010

Treatment of 6β-bromo-4β,5-epoxy-5β-cholestan-3β-ol (IV) with lithium aluminium hydride in
tetrahydrofuran at reflux for 16 hr gave a high yield of a new diol, C27H48O2,
formulated as 4,5-seco-4,6-cyolo-6β- cholestane-3β,5α-diol (VIIa).
This assignment follows from mechanistic considerations, and the chemical and
physical properties of the dial and its transformation products. ��� Stepwise removal of the oxygen functions
gave the new hydrocarbon 4,5-seco-4,6-cyclo-6β-cholestane
(XIXg).
Synthesis of polydepsipeptides with regularly repeating unit sequences
Authors: Stewart FHC
Published: September 2010

Sequential
polydepsipeptides have been obtained by linear condensation of depsipeptide
p-nitrophenyl ester active monomers. One of the products, poly-L-prolyl-L-alanylglycollic acid, is a depsipeptide analogue
of a known polypeptide model for collagen. Synthesis of the active monomers
involved the use of the pentamethylbenzyl carboxyl- protecting group, and the
formation of depsipeptide ester bonds by accelerated active ester coupling.
Thio derivatives of β-diketones and their metal chelates. XI. Stability constants of nicke(II), copper(II). zinc(II), cadniium(II), and lead(II) chelates of two monothio-β-diketones
Authors: Livingstone SE , Sullivan EA
Published: September 2010

The acid dissociation
constant (pKD) of the monothio derivative of benzoyl-acetone, viz.
3-mercapto-1-phenylbut-2-en-1-one (I), was found to be 10.43 in 74.5 vol. %
dioxan-water solution. Stoicheiometric stability constants (log kn)
of five metal chelates of (I) and of the monothio derivative of
dibenzoylmethane, viz. 3-mercapto-1,3- diphenylprop-2-en-1-one (II), have been
measured in 74.5 vol. % dioxan- water solution with both chloride and
perchlorate as supporting electrolyte. ��� With chloride as supporting electrolyte the
values obtained for log kav are as follows: with ligand (I),
copper(II) 10.11, nickel(II) 9.25, zinc(II) 6.68, lead(II) 6.06, cadmium(II)
6.12; with ligand (II), copper(II) 10.66, nickel(II) 10.20, zinc(II) 7.44,
lead(II) 7.11, cadmium(II) 6.90. With perchlorate as supporting electrolyte
zinc, lead, and cadmium give values of log kav which are 1.5-1.9
units greater. The thermodynamic stability constants (logKn)
were calculated from the stoicheiometric constants by use of the equations

���������� Log K1 = logk1 + 2.30������� logK2
= log k2 + 1.15

For the copper and nickel
complexes of both (1) and (II) log Kav is greater than pKD;
such a situation has been reported in only a few instances. ��� From the data obtained with chloride as a
supporting medium, approximate stoicheiometric stability constants were
calculated for the chloro complexes MCl+ (M
= Zn, Cd, Pb) in 74.5 vol.
% dioxan. The values obtained were: ZnCl+,
5.0; CdCl+, 5.7; PbCl+,
5.0.
Metal template reactions. I. Benzilic acid rearrangement of 2,2'-pyridil and related compounds promoted by nickel(II) and cobalt (II) ions
Authors: Black DSC , Srivastava RC
Published: September 2010

Reaction of 2,2?-pyridil
with methanolic nickel(II) and cobalt(II) acetates results in the formation of
metal complexes of 2,2?-pyridilic acid. This benzilic acid rearrangement is
undergone similarly by 2,2?- quinaldil but not by benzil, 2,2?-furil, or I-phenyl-2-(2?-
pyridyl)ethane-1,2-dione. Possible mechanisms for this rearrangement are
discussed.
Hydroxamic acids. IV. The synthesis of O-alkylhydroxamic acids
Authors: Hearn MTW , Ward AD
Published: September 2010

The synthesis of O-alkylhydroxamic
acids by the coupling of alkoxyamines with carboxylic acids using carbodiimides
and by the Wolff rearrangement of diazoketones in the presence of alkoxyamines
is discussed.
The ionization constants of phenolic groups in hydroxynaphthalenesulphonic acids
Authors: van Gemert JT
Published: September 2010

Ionization constants of the
hydroxyl group have been determined for a series of hydroxynaphthalenesulphonic
acid salts. Thermodynamic pKa values have been determined for one
mono- and one di-sulphonate. The effect of ionic strength is twice as great for
the sulphonates as for naphthols. A large difference in acid strength between
1- hydroxynaphthalene-2-sulphonate and 2-hydroxynaphthalene-1-sulphonate has
been explained in terms of interaction with the peri-hydrogen atom in the
latter. Dewar and Grisdale's expression for substituent effects has been
applied to the hydroxynaphthalenesulphonates with nonadjacent substituents. It
is concluded that the limitations of the FM treatment are most severe with
strongly dipolar substituents and with reaction sites such as -OH and -NH,
capable of inducing secondary resonance effects.
Ultraviolet absorption spectra and circular dichroism of divalent metal complexes containing 1,10-phenanthroline and 2,2'-bipyridine
Authors: Bray RG , Ferguson J , Hawkins CJ
Published: September 2010

The absorption spectra of
the following complexes have been measured at 77�K: Zn bipy32+,
Ni bipy32+, Ni en2 bipy2+,
Ni phen32+, Ni en2 phen2+,
Ni phen2- bipy2+,
and Ni bipy2 phen2+.
The fluorescence spectrum of Zn bipy32+
has also been determined. The results have been used to sort out the energy
levels associated with the π-π* transitions in the region 28000-
40000 cm-1 of the spectra of the complexes. In particular, vibronic
coupling theory for trimers has been used to determine the magnitude and sign
of the resonance splitting energies (ε) of the tris complexes. An upper
limit of 100 cm-1 (of unknown sign) can be placed on ε for bipy and there is evidence to suggest a small positive
value of ε for the 37000 cm-1 state of phen
in Ni phen32+. The
absorption spectra have been used to interpret the circular dichroism reported
previously and the vibronic coupling theory has been used successfully to
calculate the shape of the circular dichroism curve of l-Ni bipy32+,
Current theories of the circular dichroism of these complexes are critically
reviewed.
Organophosphoryl complexes of zirconium tetrachloride
Authors: Kautzner B , Wailes PC
Published: September 2010

A number of coordination
complexes of zirconium tetrachloride with phosphoryl ligands of the type (RO)3PO,
(RO)2P(O)R?, ROP(O)R?2, and R3PO have been
prepared and characterized as complexes of the type ZrCl4,2L. The
shifts of the phosphoryl stretching frequency in the infrared on complex
formation have been measured and are discussed with reference to the
electronegativity of the substituents on the phosphorus atom.
Cyclitols. XXX. The deamination of inosamines by nitrous acid
Authors: Angyal SJ , Murdoch JS
Published: September 2010

The deamination of
inosamines with nitrous acid gives a mixture from which only small amounts of
inositols can be isolated. However, L-1- amino-1-deoxy-chiro-inositol yields
the epoxide, L-1,2-anhydro-myo- inositol, in 60% yield. The penta-O-acetates of
the inosamines give inositols in good yield; in several cases the penta-O-acetyl
inositols were isolated. The extent of inversion in this displacement reaction
varies with the configuration of the inosamine from complete inversion to
predominant retention of configuration. Elimination also occurs during
deamination and results in the formation of an enol acetate. Hydrogenation of
3-deoxy-3-nitro-muco-inositol in neutral solution gives mainly
3-amino-3-deoxy-epi-inositol.
Studies using radioisotopes. III. The biosynthesis of acridone alkaloids
Authors: Prager RH , Thredgold HM
Published: September 2010

The biosynthesis of
acridone alkaloids has been investigated in Acronychia baueri and Evodia xanthoxyloides.
Anthranilic acid, N- methylanthranilic acid (XI), acetate, and
4-hydroxy-N-methylquinol-2- one (X) are incorporated, and tryptophan appears
not to be. Evidence for the existence of (II), (X), (XI), and N-acetylanthranilic
acid as metabolites of anthranilic acid in Acronychia baueri is presented. The
later, hydroxylation, stages have not yet been clarified.
An electron spin resonance study of γ-irradiated lithium DL-lactate
Authors: Whelan DJ
Published: September 2010

An e.s.r. study of single
crystals of lithium DL-lactate, irradiated at room temperature, indicates that
the free radical CH3C(OH)CO2-Li+ is trapped in
the crystalline matrix and from the magnitude of the isotropic hyperfine
splitting parameters of the methyl protons (53.0 MHz) and the hydroxyl group
(9.3 MHz),it is inferred that extensive polarization of the orbital containing
the unpaired electron into the carboxylate and hydroxyl groups occurs.
Experiments on powdered lithium DL-lactate show that this free radical is
formed at the end of a reaction sequence. When lithium DL-lactate is irradiated
at 77�K, the low temperature e.s.r. pattern originates from CH3CHCO2-Li+
and it is only on warming the sample that the fragment CH3C(OH)CO2-Li+
is formed. A similar reaction sequence has also been noted in irradiated glycollic acid.
New alkaloids from a Popowia species (Annonaceae)
Authors: Johns SR , Lamberton JA , Li CS , Sioumis AA
Published: September 2010

A bisbenzylisoquinoline
and three noraporphine alkaloids have been isolated
from the bark of a Popowia
species (Popowia
cf. cyanocarpa
Laut. 85 K. Schum.) of the
family Annonaceae. The major alkaloid is 1-hydroxy-2,9,10-trimethoxynoraporphine (1), and comparison with the known
alkaloid wilsonirine, to which the same structure had
been assigned, indicates that the Popowia base is the (+)-form, while

wilsonirine is largely racemic.
Another alkaloid, 2-hydroxy-1-methoxynoraporphine
(3), is identical with the known alkaloid asimilobine,
while the third noraporphine, 1-hydroxy-2,10,11-trimethoxynoraporphine (4), has not previously been
reported. The bisbenzylisoquinoline
alkaloid, dauricine O-methyl ether (6), has not
previously been isolated as an alkaloid but it has been prepared as a
derivative of dauricine.
Ligand exchange kinetics in the calcium-EDTA system
Authors: Bryson A , Fletcher IS
Published: September 2010

Rate constants and
associated enthalpies and entropies of activation have been determined for
reactions occurring at equilibrium in solutions containing K2CaEDTA
and KαH4-αEDTA,
where x is a stoicheiometric number. The reactions,
which include exchange between the bound ligand in CaEDTA2-
and the various protonated forms of the free ligand
as well as the formation and decomposition reactions of CaEDTA2-
and CaHEDTA-, have been investigated by N.M.R.
techniques using the Job method of continuous variations. Reaction mechanisms
are proposed.
Copper(II) complexes containing mixed β-diketone chelates
Authors: Nicholas LF , Walker WR
Published: September 2010

Copper(11) complexes of the
type [CuAB]O, where A and B are the β-diketones
acetylacetone (Hacac), trifluoroacetylaoetone
(Htfa), hexafluorylacetylaoetone
(Hhfa), thenoyltrifluoroacetone
(Htta), or benzoylacetone (Hbza), have been prepared and investigated. The compounds Cu(acac)(tta), Cu(acac)(bza), Cu(tfa)(tta), Cu(tfa)(bza), Cu(hfa)(tta), Cu(hfa)(bza),
and Cu(tta)(bza) are
described for the first time. They have been investigated by physicochemical
methods and are discussed in the light of recently reported findings on Cu(aoac)(tfa), Cu(acac)(hfa), and Cu(tfa)(hfa). However, it must be pointed
out that these complexes may possibly be mixtures of mostly [CuAB]0 with slight yet equal amounts of CuA2 and CuB2.
Carbonyl halides of the Group VIII transition metals. IV. Halocarbonyls and halocarbonyl anions of rhodium(III) and rhodium(I)
Authors: Colton R , Farthing RH , Knapp JE
Published: September 2010

Both rhodium trichloride
and tribromide are easily carbonylated
and subsequently reduced by refluxing formic acid-hydrohalic acid mixture to
give almost quantitative yields of the rhodium(1) halocarbonyl anions [Rh(CO)2X2]- (X = Cl,Br).
It has been shown that the
reaction proceeds by the intermediate formation of the rhodium(111)
halocarbonyl anions [Rh(CO)X5]2-
followed by slow reduction to the rhodium(1) complexes. Evaporation of the
respective solutions leads to almost quantitative recovery of the new rhodium(111)
halocarbonyls Rh(CO)X3 and the well known
rhodium(1) compounds [Rh(C0)2X]2.

Iododicarbonylrhodium(1) could not be isolated by this method and in fact
the only products which could be isolated were triiodocarbonylrhodium(111),
Rh(CO)I3, and its corresponding anion;
this shows that although the carbonylation reaction
had occurred the subsequent reduction did not proceed. In solution the rhodium(1)
complexes [Rh(C0)2X2]- oxidize
to give [Rh(CO)X5]2-.
Caesium salts of these rhodium(111) anions are readily isolated, but addition
of caesium salts to the rhodium(1) solutions did not give the expected Cs[Rh(CO)2X2] but instead the octahedral
complexes Cs2[Rh(C0)2(H2O)X3].
All of these changes in
composition and oxidation state have been followed in solution, as well as in
the isolated solid products, by infrared spectroscopy.
The synthesis of 6,7-Dihydrocyclohepta[opqr]benzo[c]phenanthrene
Authors: Craig JT
Published: September 2010

6,7-Dihydrocyclohepta[opqr]benzo[c]phenanthrene, the first example of a hydrocarbon containing a
seven-membered ring with four contiguously fused aromatic rings, has been
prepared. A preliminary examination of the n.m.r, spectrum shows the signal
from the four aliphatic protons coalesce to a sharp singlet at temperatures
above -40�. Attempts to dehydrogenate this compound to the fully unsaturated
hydrocarbon were unsuccessful.
Photocarrier generation mechanisms in anthracene crystals under ultra-high vacuum
Authors: Johnston GR , Lyons LE
Published: September 2010

A detailed investigation of
the transient photocurrents generated in anthracene
single crystals has been undertaken. The variations of the measured currents
with the wavelength and intensity of the incident light, the applied voltage,
and the temperature of the crystal are given for crystals both before, and
after, subjection to ultra-high vacuum. Removal of the surface by evaporation
is seen to produce large changes in the
observed photocurrents. A biphotonic generation
process for both hole and electron currents at high light intensities is
observed after prolonged evacuation. Theoretical considerations show this biphotonic process to be singlet-exciton/singlet-exciton
collision annihilation with a rate constant of 1.8 x 10-18�0.5 m3/s.
Surface generation of holes is shown to decrease upon evacuation and to grow on readmission of oxygen.
After prolonged evacuation, the bi-excitonic
mechanism for hole generation almost completely swamps the
"extrinsic" generation at the surface. However, the electron current
becomes predominantly monophotonic with evaporation
of the surface.
Two modes of chelation in Bis(4-iminopentane-2,3-dione 3-oximato)nickel(II)
Authors: Lacey MJ , Macdonald CG , Shannon JS , Collin PJ
Published: September 2010

The red, neutral, diamagnetic nickel complex formed by the reaction of bis(pentane-2,4-dionato)nickel(II) with nitrite and ammonium ions has been investigated by p.m.r., infrared, and mass spectrometry. It is proposed that this complex has a novel unsymmetrical structure in which the ligand [CH3COC(NO)C(NH)CH3]- exhibits two different modes of chelation in the same molecule. The modes differ in that an oximino nitrogen-to-nickel bond in one chelate ring is replaced by an oximino oxygen-to-nickel bond in the other. 2H-, 15N-, and 18O-labelled derivatives of the complex have been prepared and the isotopic shifts observed in the infrared spectra have been used to assign particular vibrational modes. An analogous unsymmetrical structure is also proposed for bis(1-ethoxyoarbonyl-2-iminopropan-1-one oximato)nickel(II).
Infrared spectral studies and some reactions with common solvents of molybdenum oxide tetrachloride and molybdenum oxide trichloride
Authors: Barraclough CG , Kew DJ
Published: September 2010

The infrared spectrum of MoOCl4 in the gas phase has been observed over a wider frequency range than has been previously reported. The spectrum is consistent with that predicted for a vapour of monomeric molecules with a square pyramid structure. In inert solvents such as carbon tetrachloride or cyclohexane the same structure occurs, while in acetone and ether the spectra are more complex due to reaction of the oxide halide with the solvent. The reaction products have been determined from an analysis of the spectra together with gas-chromatographic analysis. Infrared spectra of chlorobenzene, acetone, and diethyl ether solutions of the oxide trichloride MoOCl3 are also reported and it is suggested that this substance is dimeric in the latter two solvents. Changes that occur in the carbon tetrachloride cyclohexane, and chloroform solution spectra of MoOCl4 when traces of water are added are described and discussed. It is tentatively proposed that an oxygen bridged dimer is formed.
The synthesis of some substituted methyl pyridinecarboxylates. I. Methyl 6-substituted picolinates, methyl 6-substituted nicotinates, and methyl 2-substituted isonicotinates
Authors: Campbell AD , Chan E , Chooi SY , Deady LW , Shanks RA
Published: September 2010

General methods for the
synthesis of methyl 6-X-picolinates, methyl 6- X-nicotinates, and methyl
2-X-isonicotinates (X = NO2, Br, MeO, Me2N) from the
appropriate 2-amino-n-methylpyridine (n = 6, 5, 4 respectively) are described.
Preparations of methyl 6-methylpicolinate and methyl 2-methylisonicotinate from
the corresponding lutidines are given also.
Polyamine ligands. III. Five-coordinate complexes with the quinquedentate N,N,N'-Tris[2-(2'-pyridyl)ethylethylenediamine
Authors: Phillip AT , Mazurek W , Casey AT
Published: September 2010

The quinquedentate ligand,
N,N,N?-tris[2-(2?- pyridyl)ethyl]ethylenediamine (tpen), has been synthesized
from ethylenediamine and 2-vinylpyridine. The free amine tpen is thermally
unstable, but readily forms chemically stable metal complexes of the composition
[M(tpen)](ClO4)2 (M = Cu, Ni, Zn) and [Co(tpen)O2Co(tpen)]-
(ClO4)4. In each of these compounds, the amine tpen is
bonded to the metal ion through all five of its nitrogen atoms, as indicated by
infrared and electronic absorption spectra and magnetic susceptibility
measurements. The compound [Ni(tpen)](ClO4)2 shows four
d-d transitions whose energies correspond closely to the values predicted from
a ligand field calculation for a square pyramidal NiN5 chromophore.
This structure has been confirmed by X-ray diffraction analysis. These
complexes of tpen are the first reported quinquedentate pentaamine chelate structures
of copper(II), nickel(II), and zinc(II).
Flavan derivatives. XXX. Synthesis of racemic peltogynol trimethyl ether and its cis-cis-stereoisomer
Authors: Clark-Lewis JW , Mahandru MM
Published: September 2010

Synthesis of (�)-peltogynol
trimethyl ether [(�)-trans-trans-7,6?,7?-
tri-methoxyisochromano(4?,3?:2,3)chroman-4-ol and its (&)-cis-cis- stereoisomer
are described. (+)-Peltogynol tetramethyl ether is shown to be the
trans-trans-4,7,6?,7?-tetramethyl ether, and acid-catalysed etherification of
the (�)-cis-cis-stereoisomer of peltogynol trimethyl ether with methanol is
shown to yield the (�)-2,3-cis-3,4-trans- 4,7,6?,7?-tetramethyl ether.
Oxidation of cis-cis-2?-hydroxymethyl- 7,4?,5?-trimethoxyflavan-3,4-diol with
manganese dioxide gave 3(3?)- hydroxy-7,6?,7?-trimethoxyisochromano(4?,3?:2,3)chroman-4-one
(a hemiacetal) and 2?-formyl-7,4?,5?-trimethoxyflavonol. Similar oxidation of
trans-trans-2?-hydroxymethyl-7,4?,5?-trimethoxyflavan-3,4-diol gave minor quantities
of the hemiacetal and 2?-formyl-7,4?,5?- trimethoxyflavonol, and yielded mainly
the 2,3-trans-3-hydroxy- flavanone. N.m.r. data are presented for the compounds
described.
Chemistry of the Podocarpaceae. XXXI. Reactions of ring-A epoxy derivatives of 18-Norabieta-8,11,13-triene and 12-Methoxy-18-norpodocarpa-8,1 1,13-triene
Authors: Cambie RC , Franich RA , Fullerton TJ
Published: September 2010

Products from the reaction
of boron trifluoride and dimethyl sulphoxide on the 3α,4α-epoxy (7;
8), 4α,19-epoxy (9; 10), and 4α,5α-epoxy (11; 12) derivatives of
both 18-norabieta-8,11,13-triene and 12-methoxy-18- norpodocarpa-8,11,13-triene
are described. The mode of formation of the products is discussed, and a
previous examination of the action of boron trifluoride in benzene on these
epoxides is completed.
Spectroscopic studies on thiobis(β-diketones) and their polymeric metal complexes
Authors: Jones RDG , Power LF
Published: September 2010

Coordination compounds of
some first-row transition metals have been prepared with thiobis(β-diketones).
The compounds are polymeric, the degree of polymerization being small. The
compounds have low thermal stability. ��� The infrared spectra and proton magnetic
resonance spectra of the ligands show that the β-diketone residues are
strongly enolized, in agreement with the results of X-ray and neutron
diffraction studies to be reported elsewhere. Structures for the polymeric
metal complexes are suggested based on the known structures of the ligands and
on spectral data in the visible region.
An E.S.R. study of radical intermediates in the photoreduction of xanthene dyes
Authors: Leaver IH
Published: September 2010

E.s.r. spectra are reported
for the semireduced radicals of fluorescein, eosin Y, and rose bengal B, formed
during the photolysis of these dyes in alcohol solutions of various indole
derivatives and triethylamine. When indoleacetic acid is used as substrate, the
dye radicals exist as the diprotonated monoanion radicals, with OH proton
splitting constants varying from 0.12 G (fluorescein) to 1.0 G (rose bengal B).
In the presence of tryptamine or triethylamine the intermediate dye radicals
exist as the unprotonated radical trianions. The e.s.r. spectrum of the
semireduced monoanion radical of rhodamine B was also observed during
photolysis of the dye in the presence of triethylamine.
Vibrational spectra of cyclopentadienyltrimethylplatinum(IV)
Authors: Hall JR , Smith BE
Published: September 2010

The Raman spectra of cyclopentadienyltrimethylplatinum(IV)
in the solid state and solution have been recorded and interpreted in
conjunction with the corresponding infrared spectra over the range 4000-30 cm-1.
Assignments have been made on the basis of local symmetry. Polarized Raman
lines at 561 and 263 cm-1 have been assigned to symmetric Pt-CH3
stretching and Pt-cp stretching vibrations respectively. The spectral data are
consistent with a pentahapto π-bonded cp ring.
The d.c. and a.c. polarography of some substituted azobenzenes in acetonitrile
Authors: Boto KG , Thomas FG
Published: September 2010

The d.c. and a.c. polarographic behaviour of several 4-monosubstituted
azobenzenes in acetonitrile is reported. For all oompounds studied, two one-electron
reduction steps are observed. The first reduction step is reversible and the second
step is meversible, except for 4-nitroazobenzene where both reduction steps are
reversible. The half-wave potentials of the reversible steps are directly related to
the Hammett substituent constants. Small amounts of water have a marked effect on
both the half-wave potentla1 and diffusion current of the second reduction step.
Vibrational spectra of halomercurate(II) complexes in solution
Authors: Hooper MA , James DW
Published: September 2010

The Raman spectra of
solutions in acetone of crystalline salts with anionic stoicheiometries HgX3-, HgX42-,
Hg2X5-, and Hg3X82-
(where X = Cl, Br, or I) were determined. The
dominant species identified in all cases except (pyH)2HgI4 was HgX3-
which probably had a bent (C3v) configuration. The species Hg2I5- was also identified in
solutions of Me4NHg.2I5.
The disproportionation reactions are discussed in terms of ion-solvent
interactions.
Ligand design and synthesis. III. Cyclic multidentate ligands with 12- and 18-membered rings
Authors: Black DSC , McLean IA
Published: September 2010

A number of cyclic ligands
has been prepared by the high-dilution technique. All these ligands have their
donor-atoms linked by ethano bridges. Examples of a non-planar quadridentate
and three potential sexadentates were prepared. The cyclic quadridentete,
1-oxa-4,10- dithia-7-azacyclododecane (1), formed neutral complexes of the type
[MLX2], where M = Co, X = Cl, Br and M = Ni, X = Cl, which are octahedral
and presumably have the halide ligands cis to each other. Two of the cyclic
ligands, 1,4,10,13-tetrathia-7,16- diazacyclooctadecane (3) and 1,4,7,10,13,16-hexathiacyolooctadecane
(4), are the first reported cyclic sexadentates which form octahedral
complexes, and the first examples of cyclic sexadentate ligands prepared
without the aid of the metal template effect. Complexes of the type
[ML](picrate)2, where M = Co, Ni, were prepared from ligands (3) and
(4). A third potential sexadentate, 1,10-dioxa-4,7,13,16- tetrathiaoyolooctadecane
(5), did not form complexes when treated with MX2, where M = Co, Ni,
Fe, Cu and x = Cl, ClO4.
Organomercury compounds. XII. The synthesis of diarylmercurials and arylmercuric arenesulphinates by sulphur dioxide elimination reactions
Authors: Cookson PG , Deacon GB
Published: September 2010

The diarylmercurials, R2Hg
[R = Ph, p-XC6H4 (X = Me, Br, Cl, or F), 2,3,4-Cl3C6H2,
2,4,5-Cl3C6H2, 2-naphthyl, or 8-quinolyl],
have been prepared in satisfactory yield by sulphur dioxide elimination reactions
on heating the corresponding mercuric arenesulphinates under vacuum, but
decomposition of mercuric p-acetamidobenzenesulphinate gave acetanilide. The
mercuric arenesulphinates were obtained by reaction of mercuric acetate with
the appropriate sodium arenesulphinates in aqueous solution at room temperature.
Similar reactions in boiling aqueous solution gave either diarylmercurials, R2Hg
[R = Ph, p-XC6H4 (X = Me, F, or MeCONH), 2,4,6-Me3C6H2,
2,4,6-(Me2CH)3C6H2, or 8-quinolyl],
or arylmercuric arenesulphinates, RHg(02SR) [R = p-XC6H4
(X = Br or Cl), 2,3,4-Cl3C6H2, 2,4,5-Cl3C6H2,
or 2-naphthyl], usually in low yield, and sulphur dioxide. Mercury-carbon bond
formation also occurred in reactions of mercuric acetate with sodium
mesitylenesulphinate and 2,4,6-triisopropylbenzenesulphinate at room
temperature, mesitylmercuric mesitylenesulphinate and bis(2,4,6- triisopropylphenyl)mercury,
respectively, being obtained. The sulphur- oxygen stretching frequencies of the
mercuric arenesulphinates are indicative of S-sulphinate coordination, whilst
those of the arylmercuric arenesulphinates are consistent with unidentate O- sulphinate
groups.
The nature of complexes of tetrasulphur tetranitride with Lewis acids
Authors: Paul RC , Arora CL , Kishore J , Malhotra KC
Published: September 2010

Complexes of tetrasulphur
tetranitride with antimony pentachloride, selenium tetrachloride, tellurium
tetrachloride, and boron trichloride, and adducts of these complexes with
sulphur trioxide, have been prepared. Physical data have been collected and
structures proposed.
The reactions of 4-nitrophenylhydrazine and phenylhydrazine with formaldehyde
Authors: Johns SR , Lamberton JA , Nelson ER
Published: September 2010

A comparison has been made
of the reaction products from 4-nitrophenyl- hydrazine and formaldehyde with
those obtained from phenylhydrazine and formaldehyde. Formaldehyde
4-nitrophenylhydrazone does not form a stable dimer analogous to
1,4-diphenylhexahydro-s-tetrazine (1) formed from formaldehyde phenylhydrazone.
On heating formaldehyde 4- nitrophenylhydrazone to 180�, or on heating a
solution of the monomer in glacial acetic acid, oxidative coupling takes place
to give glyoxal bis(4-nitrophenylhydrazone). Three products from 4-nitro-
phenylhydrazine and excess formaldehyde have been shown to be (6), (7), and
(8), with the unsymmetrical C16H16N6O5
isomer (8) predominant. An explanation has been provided for the formation of
the symmetrical and unsymmetrical C16H16N6O5
isomers (7) and (a), both having a -CH2OCH2- grouping,
and of only one -CH2- bridged product. Alternative structures are
suggested for an ethoxy compound, (11) or (12), formed from 4- nitrophenylhydrazine and formaldehyde in ethanolic
solution. The N.M.R. spectra of a number of reaction products have been
examined, and an unusual long-range coupling has been observed between the C 3
and C 5 methylene group protons in 4-anilino1-2-phenyl-2,3,4,5-tetrahydro-
1,2,4-triazine (4).
The synthesis and properties of Tris(dithioacetylacetonato) complexes of cobalt(III), rhodium(III), and iridium(III)
Authors: Heath GA , Martin RL
Published: September 2010

.The syntheses of the cobalt(III), rhodium(III), and iridium(III) complexes of
dithioacetylacetone, [M(SacSac)3], are described. The tris-chelates are neutral dia-
magnetic monomers. Infrared, proton magnetic resonance, and electronic spectra
are reported. Polarography in acetone shows that these complexes are reduced at
more negative potentials than those of the iron(III) group. Various related complexes
[Co(SacSac)2(X-Y)] have also been prepared.
M÷ssbauer studies in transition metal chemistry. I. Compounds of iron with Dithioacetylacetone (Pentane-2,4-dithione)
Authors: Martin RL , Roos IAG
Published: September 2010

The temperature dependence
of the Mossbauer spectra of some iron- containing compounds of
dithioacetylacetone are reported between 4 and 293 K. ��� The quadrupole splitting ΔEq
of [Fe(SacSac)3] is larger than usually
observed for low-spin six-coordinated iron(III) and is ascribed to the lifting
of orbital degeneracy of the 2T2 ground state by small
axial and rhombic distortions. ��� The unsubstituted and phenyl-substituted
dithiolium salts of [FeCl4]2-
exhibit strongly temperature-dependent quadrupole splittings, which arise
directly from the lifting of the orbital degeneracy of the 5E ground
state due to distortion of the [FeCl4]2-
tetrahedron.
Circular dichroism spectra of 2-substituted propionatopentaaminocobalt(II) complexes
Authors: Hawkins CJ , Lawrance GA
Published: September 2010

The preparations of a
series of optically active complexes with the general formula Co(NH3)5(OCOCH(X)CH3)2+
are reported for X = NH3+, OH, F, Cl,
Br, C2H5, and C6H5. The circular
dichroism spectra of the complexes have been measured in aqueous solution, in
the presence of salts of polarizable anions, and in KBr
disks. The spectra have been analysed in terms of three Cotton effects under the
1A1g → 1T1g cubic absorption
band and found to be consistent with a +, -, - sign pattern for the L- isomer,
corresponding to the two components of the 1A1g → 1Eg
(D4h) and to the 1A1g → A2g (D4h) transition, respectively.
Solutions of phenyliodoso acetate. Decomposition in acetic acid and the effect of perchloric acid
Authors: Johnson WD , Sherwood JE
Published: September 2010

Phenyliodoso acetate
appears capable of sustaining both free-radical and ionic reactions.
Conductivity studies on solutions of phenyliodoso acetate in acetic acid
indicate a small degree of ionic dissociation at temperatures above room
temperature. Photolysis of the iodoso compound is a zero-order reaction and a
homolytic mechanism is proposed for the decomposition. Evidence from
conductivity and spectroscopic studies indicates that there is interaction
between the iodoso compound and hydrogen ions. The decomposition of
phenyliodoso acetate in acetic acid is markedly accelerated by the addition of
perchloric acid. In the absence of acid no conclusion about mechanism is
possible; when acid is present decomposition occurs by an ionic mechanism.
Reactions of pyrazine radical anions in solution. I. Study of the kinetics of the dimerization of pyrazine radical anions
Authors: Hay RS , Pomery PJ
Published: September 2010

The radical anions of pyrazine (pz-.) have been prepared at 294'K by reducing
pyrazine (pz) with metallic potassium in 1,2-dimethoxyethane (dme). The resulting
reactions of the radical anions are postulat'ed as being described by the equations:
The e.s.r, and electronic absorption spectra of all pertinent species were
recorded and examined. The kinetics of reaction (1) have been investigated in the
dark as well as in light and values of the rate constants have been determined. I n
light, reaction (1) did not conform strictly to second-order kinetics and this may be
explained by an interaction of pyrazine with dme. The dimer dianion species
(-pz-pz-, 2K7) was found to be stable in the dark but decayed slowly in light.
This decay was found to exhibit first-order kmetics.
Photochemical syntheses. III. The synthesis and photo-isomerization of 1,2-Diphenyl-2a,8b-dihydrocyclobuta[a]naphthalene and some derivatives
Authors: Collin PJ , Sasse WHF
Published: September 2010

Fourteen derivatives of the
naphthalene-diphenylacetylene photo-adduct (1a) have been thermally isomerized
to give high yields of derivatives of 1,2-diphenyl-2a,8b-dihydrocyclobuta[a]naphthalene
(1b). Of these only the 4-methoxy derivative (13b) could be rearranged to the
isomeric benzocyclooctatetraene (13c). Five alkyl and one methoxy derivative of
(1b) were quantitatively isomerized to derivatives of (1a) but the
isomerization of the esters (10b) and (11b) gave mixtures. Photo-iso-
merization of the methoxybenzocyclooctatetraene (13c) gave exclusively (13b)
and (13a). ��� Mechanistic aspects of these reactions are
discussed.
Synthesis of 5-n-alkylresorcinol dimethyl ethers and related compounds via substituted thiophens
Authors: Buddhasukh D , Cannon JR , Metcalf BW , Power AJ
Published: September 2010

5-n-Alkylresorcinol
dimethyl ethers have been synthesized by desulphurization of
2-(3,5-dimethoxybenzyl)-5-n-alkylthiophens with Raney nickel. The method has
been adapted to the preparation of 9-(3,6- dimethoxyphenyl)nonyl alcohol which
has been converted into both (2)- and (E)-15-(3,5-dimethoxyphenyl)pentadec-5-ene.
��� Friedel-Crafts acylation of
2-(3,5-dimethoxybenzyl)thiophen with n- hexoyl chloride, or with n-decoyl
chloride, in the presence of stannic chloride, yielded the expected 2-(3,6-dimethoxybenzyl)-5-n-
acylthiophens, but by-products were formed as the result of competing
electrophilic attack on the 3,5-dimethoxybenzyl moiety. The chief by- products,
which arise by subsequent Bradsher cyclodehydration, have been formulated as
5,7-dimethoxy-4-n-alkylnaphtho[2,3-b]thiophens. ��� An attempt to synthesize
1,14-bis(3,5-dimethoxyphenyl)tetradecane from 2,2?,6?,2?-terthienyl by an
adaptation of this method was unsuccessful.
Studies on intramolecular alkylation. II. The preparation of intermediates for diterpene synthesis by intramolecular carbenoid addition reactions
Authors: Beames DJ , Halleday JA , Mander LN
Published: September 2010

A new method is described
for the preparation of tricyclic compounds containing the 3,2,1- and
2,2,2-bicyclooctane ring systems. The copper-catalysed decomposition of the
diazomethyl ketones derived from the olefinic acids (7), (9), (18), and (19)
afforded, respectively, the cyclopropyl ketones (12), (13), (21), and (20).
These compounds were transformed into the cyolopropyl diketones (15) and (22)
which by treatment with dilute acid or base gave, in turn, the bridged
octalones (1) and (2).
Annelated furans. VII. Synthetic routes to Di-O-methylstrepsilin
Authors: Brewer JD , Elix JA
Published: September 2010

Two unambiguous syntheses
of di-O-methylstrepsilin
are reported. Both schemes involved a Diels-Alder
addition of dimethyl acetylenedicarboxylate to a 2-(β-methoxyvinyl)benzofuran in the key step. The synthetic di-O-methylstrepsilin
so obtained was found to be identical with a sample obtained by methylation of
the natural material, thereby confirming the structure of this compound and
hence of strepsilin itself. The partial oxidation of
several 1,2-bishydroxymethyldibenzofursns was studied. Vilsmeier-Haack
formylation of 3-acetoxy-6-methoxy-4-methylbenzofuran
(29) was found to proceed in an abnormal manner, giving rise to
3-chloro-6-methoxy-4-methylbenzofuran-2-carbaldehyde (31) as well as the
unprecedented 3-(3'-chloro-6'- methoxy-4'-methylbenzofuran-2'-yl)-N,N-dimethylacrylamide (32). The mechanism for the formation of
the latter compound has been discussed and interpreted as a Perkin-like
condensation.
The synthesis of Benzo[4,5]cyclohepta[1,2,3-de]naphthalene
Authors: Craig JT , Pitt MA , Tan KW , Woolhouse AD
Published: September 2010

Muller et al have recently
reported a synthesis of benzo[4,5] cyclohepta[1,2,3-de]naphthalene by a
dehydrogenation reaction. Some investigations into alternative routes to this
compound are now reported. One of these succeeded in giving a compound identical
with that described by the previous workers.
The 9-decalyl and related cations. I. Generation of the 9-decalyl cation by solvolysis
Authors: Gream GE
Published: September 2010

Kinetic and product studies
have established that π-bond participation occurs in the acetolysis of
4-(cyclohex-1-enyl)but-1-yl derivatives to give a 9-decalyl cation.
Quantitative analyses of the mixtures of products formed by the x-route (from
4-(cyclohex-1-enyl)but-1-yl derivatives), π-route (from spiro[4,5]dec-6-yl
derivatives), and direct routes (from cis-
and trans-9-decalyl derivatives) show
that the intermediate 9-decalyl cations generated in each case must be
different. Reasons for the differences are discussed; it is suggested that the
counter-ion in ion-pairs involving cis-like
and trans-like conformers of the
9-decalyl cation probably plays an important role in product formation.
Organoindium compounds. II. Some coordination derivatives of trispentafluorophenylindium
Authors: Deacon GB , Parrott JC
Published: September 2010

The complexes (C6F5In,L
[L = pyridine (py), Ph3P, Ph3PO, Ph3AsO, or

N,N,N?,N'-tetramethylethylenediamine
(tmed)], (CeF5)31n(OSMe2)2,
and [(C6F5)3)aIn]2bipy (bipy =
2,2'-bipyridyl) have been prepared by reaction of (C6F5)3In,diox
(diox = 1,4-dioxan) with the appropriate ligands, and
(C6F5)31n,AsPh3,( C6F5)3
(THF)2 (THF = tetrahydrofuran), and (C6F5)31n]2(Ph2PCH2)2
have been similarly obtained from (C6F5)3In,OEt2.
Monomeric structures with four-coordinate indium are proposed for the complexes
(C6F5)3In,L (L = py, Ph3P, Ph3As,
Ph3PO,or Ph3AsO), and monomeric five-coordinate
structures for the complexes (C6F5)31n(L)2
(L = Me2SO or
THF). The derivatives [(C6F5)31n]2L
[L = bipy or (Ph2PCH2)2]
and (C6F5)3In,tmed
are considered to have bridging ligands with four- and five- coordinate indium
respectively.
Involvement of p114-RhoGEF and Lfc in Wnt-3a– and Dishevelled-Induced RhoA Activation and Neurite Retraction in N1E-115 Mouse Neuroblastoma Cells
Authors: Tsuji Takuji , Ohta Yusaku , Kanno Yuya , Hirose Kenzo , Ohashi Kazumasa , Mizuno Kensaku
Published: September 2010

The Wnt-induced planar cell polarity (PCP) signaling pathway is essential for polarized cell migration and morphogenesis. Dishevelled (Dvl) and its binding protein Daam1 mediate RhoA activation in this pathway. WGEF, a member of the Rho-guanine nucleotide exchange factor (Rho-GEF) family, was shown to play a role in Wnt-induced RhoA activation in Xenopus embryos. However, it has remained unknown which member(s) of a Rho-GEF family are involved in Wnt/Dvl-induced RhoA activation in mammalian cells. Here we identified p114-RhoGEF and Lfc (also called GEF-H1) as the Rho-GEFs responsible for Wnt-3a–induced RhoA activation in N1E-115 mouse neuroblastoma cells. We screened for Rho-GEF–silencing short-hairpin RNAs (shRNAs) that are capable of suppressing Dvl-induced neurite retraction in N1E-115 cells and found that p114-RhoGEF and Lfc shRNAs, but not WGEF shRNA, suppressed Dvl- and Wnt-3a–induced neurite retraction. p114-RhoGEF and Lfc shRNAs also inhibited Dvl- and Wnt-3a–induced RhoA activation, and p114-RhoGEF and Lfc proteins were capable of binding to Dvl and Daam1. Additionally, the Dvl-binding domains of p114-RhoGEF and Lfc inhibited Dvl-induced neurite retraction. Our results suggest that p114-RhoGEF and Lfc are critically involved in Wnt-3a– and Dvl-induced RhoA activation and neurite retraction in N1E-115 cells.
Ubiquitin-mediated mRNP dynamics and surveillance prior to budding yeast mRNA export
Authors: Iglesias Nahid , Tutucci Evelina , Gwizdek Carole , Vinciguerra Patrizia , Von Dach Elodie , Corbett Anita H. , Dargemont Catherine , Stutz Françoise
Published: September 2010

The evolutionarily conserved mRNA export receptor Mex67/NXF1 associates with mRNAs through its adaptor, Yra1/REF, allowing mRNA ribonucleoprotein (mRNP) exit through nuclear pores. However, alternate adaptors should exist, since Yra1 is dispensable for mRNA export in Drosophila and Caenorhabditis elegans. Here we report that Mex67 interacts directly with Nab2, an essential shuttling mRNA-binding protein required for export. We further show that Yra1 enhances the interaction between Nab2 and Mex67, and becomes dispensable in cells overexpressing Nab2 or Mex67. These observations appoint Nab2 as a potential adaptor for Mex67, and define Yra1/REF as a cofactor stabilizing the adaptor–receptor interaction. Importantly, Yra1 ubiquitination by the E3 ligase Tom1 promotes its dissociation from mRNP before export. Finally, loss of perinuclear Mlp proteins suppresses the growth defects of Tom1 and Yra1 ubiquitination mutants, suggesting that Tom1-mediated dissociation of Yra1 from Nab2-bound mRNAs is part of a surveillance mechanism at the pore, ensuring export of mature mRNPs only.
Agarose Imprints of Plant Cell Surfaces for Imaging
Authors: Christensen Sioux
Published: September 2010

INTRODUCTION

Features of epidermal cells such as cell shape or arrangement of stomata are best studied under the scanning electron microscope. However, the preparation and viewing of samples using electron microscopy can be relatively laborious. A quick alternative is to view epidermal imprints in agarose using Nomarski differential-interference contrast microscopy. This protocol describes a method for preparing agarose imprints of plant cell surfaces.
Electrophysiological Recording from Drosophila Larval Body-Wall Muscles
Authors: Zhang Bing , Stewart Bryan
Published: September 2010

INTRODUCTION

The Drosophila larval neuromuscular junction (NMJ) shares many structural and functional similarities to synapses in other animals, including humans. These include the basic feature of synaptic transmission, as well as the molecular mechanisms regulating the synaptic vesicle cycle. Because of its large size, easy accessibility, and the well-characterized genetics, the fly NMJ remains an excellent model system for dissecting the cellular and molecular mechanisms of synaptic transmission. This protocol describes the steps for performing intracellular recording from fly larval body-wall muscles and explains how to record and analyze spontaneous and evoked synaptic potentials. Methods used include larval dissection (“filleting”), identification of muscle fibers and their innervating nerves, the use of a micromanipulator and microelectrode in penetrating the muscle membrane, and nerve stimulation to evoke synaptic potentials.
Profiling the expression of cytochrome P450 in breast cancer
Authors: Murray Graeme I , Patimalla Siva , Stewart Keith N , Miller Iain D , Heys Steven D
Published: September 2010

Murray G I, Patimalla S, Stewart K N, Miller I D & Heys S D (2010)Histopathology 57, 202–211

Profiling the expression of cytochrome P450 in breast cancer

Aims: The cytochrome P450s (P450) are key oxidative enzymes that metabolize many carcinogens and anticancer drugs. Thus, these enzymes influence tumour development, tumour response to therapy and are putative tumour biomarkers. The aim was to define the P450 expression profile in breast cancer and establish the significance of P450 expression in this tumour type.

Methods and results: A tissue microarray containing 170 breast cancers of no special type was immunostained for a panel of 21 P450s. The highest percentage of strong immunopositivity in breast cancers was seen for CYP4X1 (50.8%), CYP2S1 (37.5%) and CYP2U1 (32.2%), while CYP2J (98.6%) and CYP3A43 (70.7%) were the P450s that most frequently displayed no immunoreactivity. CYP4V2 (P = 0.01), CYP4X1 (P = 0.01) and CYP4Z1 (P = 0.01) showed correlations with tumour grade. CYP1B1 (P = 0.001), CYP3A5 (P = 0.001) and CYP51 (P = 0.005) showed the most significant correlations with oestrogen receptor status. Correlations with survival were identified for CYP2S1 (P = 0.03), CYP3A4 (P = 0.025), CYP4V2 (P = 0.026) and CYP26A1 (P = 0.03), although none of these P450s was an independent marker of prognosis.

Conclusions: This study has defined the expression profile of cytochrome P450s in breast cancer and may offer their potential application as biomarkers to aid decisions regarding optimal adjuvant hormonal therapy.
Induction of the vascular endothelial growth factor pathway in the brain of adults with fatal falciparum malaria is a non‐specific response to severe disease
Authors: Medana Isabelle M. , Day Nicholas P. J. , Roberts Rachel , Sachanonta Navakanit , Turley Helen , Pongponratn Emsri , Hien Tran Tinh , White Nicholas J. , Turner Gareth D. H.
Published: September 2010

Medana I M, Day N P J, Roberts R, Sachanonta N, Turley H, Pongponratn E, Hien T T, White N J. & Turner G D H (2010) Histopathology 57, 282–294

Induction of the vascular endothelial growth factor pathway in the brain of adults with fatal falciparum malaria is a non‐specific response to severe disease

Aims:  Pathological or neuroprotective mechanisms in the brain in severe malaria may arise from microvascular obstruction with malaria‐parasitized erythrocytes. This study aimed to investigate the role of hypoxia and induction of the vascular endothelial growth factor (VEGF) pathway in the neuropathophysiology of severe malaria.

Methods and results:  Immunohistochemistry was performed on post mortem brain tissue sections from 20 cases of severe malaria and examined for the expression of transcriptional regulators of VEGF [hypoxia‐inducible factor‐1 alpha (HIF‐1α), HIF‐2α], DEC‐1, VEGF, VEGF receptors 1 and 2, and the activated, phosphorylated VEGF receptor 2 (pKDR). HIFs showed limited protein expression and/or translocation to cell nuclei in severe malaria, but DEC‐1, which is more stable and regulated by HIF‐1α, was observed. There was heterogeneous expression of VEGF and its receptors in severe malaria and non‐malarial disease controls. pKDR expression on vessels was greater in malaria cases than in controls but did not correlate with parasite sequestration. VEGF uptake by malaria parasites was observed.

Conclusions:  VEGF and its receptor expression levels in severe malaria reflect a non‐specific response to severe systemic disease. Potential manipulation of events at the vasculature by the parasite requires further investigation.
Comparison of an Improved AFP Kit with the Intra‐Amniotic PSP Dye‐Injection Method in Equivocal Cases of Preterm Premature Rupture of the Fetal Membranes
Authors: Yamada Hideto , Kishida Tatsuro , Negishi Hiroaki , Sagawa Tadashi , Yamaguchi Masayuki , Sato Chikara , Nakamura Itsuro , Sato Hiroshi , Sakai Keiichiro , Yamaguchi Tatsumi , Fujimoto Seiichiro
Published: September 2010

Objective: We developed an improved AFP kit for detecting AFP in leaked amniotic fluid. We studied the relationship between the results of the improved AFP kit and! those of the intra‐amniotic PSP dye‐injection test (PSP test), and compared the results of two tests with the prognosis for subsequent pregnancy outcome, in order to know the diagnostic value of the two tests for preterm PROM, especially in equivocal cases.

Methods: We compared the results of the AFP kit test with those of the PSP test in 8 equivocal cases of preterm PROM (18th to 34th weeks of gestation).

Results: The results of the AFP kit test coincided with those of the PSP test in all 8 equivocal cases of preterm PROM. The 4 cases that tested positive resulted in preterm deliveries; and the other 4 cases that tested negative resulted in full‐term deliveries.

Conclusion: The use of the AFP kit test is useful in assessing the prognosis for subsequent pregnancy in equivocal cases of preterm PROM. The rapid and accurate AFP kit test for diagnosing preterm PROM can be substituted for the PSP test in bedside and outpatient‐clinic assessments.