bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction of isothiocyanates with thiourea and amidinothioureas: Formation of S-(N-substituted thiocarbamyl)isothioureas and 1-Alkyl(or aryl)-4-imino(or arylimino)-6-iminohexahydro-1,3,5-triazine-2-thiones
Authors: Joshua CP , Rajan VP
Published: September 2010

Alkyl and aryl
isothiocyanates react with thiourea in the presence of alkali to yield
S-(N-substituted thiocarbamyl)isothioureas. The
products are identified by their chemical and mass spectral characteristics.These compounds yield
5-imino-2-alkyl(or ary1)imino-1,3,4-dithiazolidine salts when oxidized in acid
medium. The parent compounds are regenerated from these dithiazolidines
on reduction with hydrogen sulphide.� Condensation of isothiocyanates with amidinothiourea and aryl amidinothioureas
on the other hand yields 1-alkyl(or
aryl)-4,6-diiminohexahydro-1,3,5-triazine-2-thiones and 1-alkyl(or
ary1)-4-arylimino-6-iminohexahydro-1,3,5-triazine-2-thione respectively.Plausible mechanisms for
these reactions are discussed.
Excess volumes for H2O + D2O liquid mixtures
Authors: Bottomley GA , Scott RL
Published: September 2010

The volume changes on
mixing D2O with H2O have been measured with a new
tilting-type dilatometer. The molar volumes are very nearly additive, but not
exactly so. At 25�C, the excess molar volume Vm
is positive, having a maximum value of about 1.8 x cm3 mol-1,
while at4�C it is negative, with a
minimum of about - 1.2-4 cm3 mol-l.
Thermodynamics of Metal-Ligand Bond Formation. XVIII Addition of Heterocyclic Bases to Copper(II) and Cobalt(II) Schiff Base Complexes
Authors: Ang L , Graddon DP
Published: September 2010

Thermodynamic data are
reported for reaction of heterocyclic bases in benzene solution with four-coordinate
copper(11) and cobalt(11) Schiff base complexes and also with a five-coordinate
nickel(11) complex. The cogper(11) complexes form
adducts of low stability with pyridine or 4-methylpyridine, K ≈ 21. mol-1,
ΔH� ≈ -20 kJmol-l. The
cobalt(11) complexes add two molar proportions of base successively

1 < K1 ≤ K2 < 101.mol-1 ΔH1� ≈ ΔH2�
≈ -20 kJ mol-1

They also form adducts with
2,2'-bipyridine

30 < K < 600 ΔH�
≈ -40kJ mol-1

The nickel(11) complex
forms more stable adducts with unidentate bases, K ≈
1001. mol-l, ΔH� ≈ 70 kJ mol-1. Comparison of
the three metals indicates that differences between the stabilities of their
base adducts can be attributed mainly to entropy factors.
The thermal decomposition of 2-chloroethanol
Authors: Skingle DC , Stimson VR
Published: September 2010

2-Chloroethanol decomposes
at 430-496� into acetaldehyde and hydrogen chloride with first-order rate given
by:

k1 = 1012.8�1 exp(-229700 � 4000/8.314T) s-l

The rate is slightly less
than that for ethyl chloride. That acetaldehyde is the product shows that a 1-2
shift of hydrogen has taken place and this is indicative of a polar transition
state.The acetaldehyde
subsequently decomposes to methane and this decomposition is catalysed by the
hydrogen chloride produced.
Regioselective oxidation of aliphatic acids by complexed hydroxyl radicals
Authors: Hewgill FR , Proudfoot GM
Published: September 2010

Radicals produced by the
TiCl3/H2O2 oxidation of various saturated and
unsaturated aliphatic acids have been identified by electron spin resonance,
and their relative concentrations have been determined by computer simulation
of the spectra. In acid solution saturated acids are oxidized principally at
the β and ω-1 (penultimate) positions, and in basic solution at the α
and ω-1 positions. A mechanism involving intermolecular oxidation of the
terminal methylene group of one acid by OH complexed
through titanium to the carboxyl group of another acid in a head to tail
oriented dimer is proposed to explain the prevalence of w-1 oxidation.
Explanations for other selective oxidations can be made in terms of inductive
and mesomeric effects. The lower unsaturated acids
react by addition of OH to the double bond. Failure to detect radicals other
than from α-hydrogen abstraction in the larger acids is attributed to
micelle formation. In some cases assignments have been confirmed by the
oxidation of related hydroxy acids, and by reduction of halogenated acids.
New Triterpenes of Lantana camara. A Comparative Study of the Constituents of Several Taxa
Authors: Hart N , Lamberton J , Sioumis A , Suares H
Published: September 2010

The triterpenes
of Lantana camara
vary widely between taxa. In taxa
toxic to livestock 22β-angeloyloxy-3-oxoolean-12-en-28-oic acid (lantadene A) and 22β-dimethylacryloyloxy-3-oxoolean-12-en-28-
oic acid (lantadene B) are
present, usually as major constituents, although 3-oxolup-20(29)-en-28-oic acid
(betulonic acid) predominates in the taxon Helidon White. 22β-Angeloyloxy-3β-hydroxyolean-
12-en-28-oic acid, 22β -dimethylacryloyloxy-3β -hydroxyolean-12-en-28-oic
acid and 22β-hydroxy-3-oxoolean-12-en-28-oic acid, not previously known to
occur in L. camara,
have been isolated as well as a number of other well-known triterpenes.
The non-toxic Townsville Prickly Orange contains small amounts of lantadenes A and B, and is the only taxon
found to contain 228-angeloyloxy-23- hydroxy-3-oxoo1ean-12-en-28-oic acid (icterogenin). Another constituent is the new triterpene
24-hydroxy-3-oxoolean-12-en-28-oic acid. Common Pink, which is non-toxic and
does not contain lantadenes A and B, is characterized
by triterpene acids which have a C3, C25 oxide-bridge. It contains lantanolic acid, lantic acid, and
a new acid, lantabetulic acid, considered to be
3,25-epoxy- 3a-hydroxylup-20(29)-en-28-oic acid. A mixture of the 22β-angeloyloxy
and 22β-dimethylacryloyloxy derivatives of lantanolic
acid from Common Pink has been converted into 22P-hydroxylantanolic acid.
Wolff-Kishner reduction of 22~-hydroxy-3-oxoolean-12-en-28-oic acid gives a low
yield of 22β-hydroxyolean-12-en-28-oic acid, and the major product is the
C22-epimer, 22a-hydroxyolean- 12-en-28-oic acid. Corresponding products are
obtained from Wolff-Kishner reduction of 22β- hydroxylantanolic
acid.
Thio derivatives of b-diketones and their metal chelates. XXII. Dipole moments of some bivalent and trivalent metal complexes of fluorinated monothio-b-diketones
Authors: Das M , Livingstone SE , Mayfield JH , Moore DS , Saha N
Published: September 2010

Dipole moments have been
determined by static polarization measurements for some iron(111), ruthenium(111),
rhodium(111), nickel(11), palladium(11), platinum(11), copper(11) and zinc(11)
complexes of fluorinated monothio-β-diketones
RC(SH)=CHCOCF3. The moments indicate a facial-octahedral
configuration for the iron, ruthenium and rhodium complexes, a cis-square-planar configuration for the
nickel, palladium and platinum complexes, and a tetrahedral configuration for
the zinc complexes. The copper complexes have moments 0.5-1.0 D lower than the
mean value for the corresponding nickel, palladium and platinum complexes; this
lowering of the moment is attributed to significant distortion from the
square-planar towards the tetrahedral configuration. The dipole moments of the
square-planar and octahedral complexes decrease if the R groups are arranged in
the order: p-MeC6H4 ≥ 2-thienyl > β-naphthyl > m-MeC6H4
> Ph > Pr? > Bui > Me > m-ClC6H4 > m-BrC6H4 > p-FC6H4
> p-ClC6H4 > p-BrC6H4 > m,p-Cl2C6H3.
Solvent structure. II. A study of the structure-making and structure-breaking effects of dissolved species in water by internal pressure measurements
Authors: Dack MRJ
Published: September 2010

Internal pressures, (∂U/∂V)T, have been
obtained at 25�C for solutions of 25 solutes in water by measurement of the
thermal pressure coefficients. Values at 1.00 M solute concentration were
plotted against the molar volume of the solutes. Those solutes (electrolytes)
which appear above a line joining five solutes acting as 'non-interacting' homomorphs were judged to be structure breakers in water;
those solutes (lithium salts, tetraalkylammonium
salts, non-electrolytes) appearing below the line were termed structure makers.
These observations are in agreement with current knowledge, and they
substantiate the present interpretation of the physical significance of
internal pressures.
Electron inductive effects in the radiolysis of substituted phenylboronic acid solutions
Authors: Brown BJ , Fitch PG , Sangster DF
Published: September 2010

The pulse radiolysis of
aqueous solutions of phenylboronic acid PhB(OH)2 and its m-nitro and m-amino derivatives has been investigated. The transient optical
absorption spectra indicate the presence of three intermediate species
absorbing with independent niaxima at 297, 317 and
400 nm. The 297-nm band has been assigned to the anion formed in an electron
capture reaction, i.e.

PhB(OH)2+eaq-
→ PhB(OH)2-

and the 317-nm band to cyclohexadienyl radicals formed from OH and H attack on PhB(OH)2. Hydroxyphenylboronic
acid has been identified as the major stable radiation product. For each of the
systems studied the respective yield and reactivity of observed intermediate
species can be interpreted relative to the electron inductive effects of
substituent groups in agreement with the Hammett relationship.
Cyclopolymerization. XII. Electron spin resonance studies of the free radical reactions of β-substituted diallylamines
Authors: Beckwith ALJ , Hawthorne DG , Solomon DH
Published: September 2010

E.s.r. spectra, and the
effects of different β-substituents on the structures and relative
proportions of isomeric pyrrolidin-3-ylmethyl and piperidin-3-yl radicals
formed during cyclization of N,N-diallylmethylamines,
are described. The hypothetical intermediate 4-azahept-6-en-2-yl radicals
undergo preferential cyclization to pyrrolidin-3-ylmethyl radicals, but the
sensitivity of this process to steric and conjugative effects is shown by the
tendency of intermediate radicals derived from suitable substituted
diallylamines to undergo alternative cyclization to piperidin-3-yl radicals.
Reaction of dicyandiamide with thiosemicarbazide and thiocarbohydrazide: Formation of 1-Amino-4-imino(or arylimino)-6-imino(or hydrazono)hexahydro-1,3,5-triazine-2-thiones
Authors: Joshua CP , Rajan VP
Published: September 2010

Dicyandiamide and aryldicyandiamides react with thiosemicarbazide
to yield 1-amino-4-imino(or arylimino)-6-iminohexahydro-l,3,5-triazine-2-thiones.
Acid hydrolysis of these compounds results in 3-amino-5-amino(or
ary1amino)-1,2,4-triazoles with loss of thiocyanic
acid, and their condensation with phenacyl bromide
yields 8-amino(or arylamino)-6-imino-3-phenyl-4H,6H-[1,3,5]triazino-[2,1-b][1,3,4]thiadiazines.Reaction of thiocarbohydrazide with dicyandiamides
affords 1-amino-4-imino(or ary1imino)-6-hydrazonohexahydro-l,3,5-triazine-2-thiones.
These compounds are converted into 8-amino(or arylamino)-6-hydrazono-3-phenyl-4H,6H-[l,3,5]triazino-[2,l-b][1,3,4]thiadiazines
by treatment with phenacyl bromide.
Extractives of Australian timbers. XVI. The constituents of the wood of Eugenia crebrinervis (syn. Syzigium crebrinerve) and Eugenia gustavioides (syn. Cleistocalyx gustavioides)
Authors: Bannon CD , Eade RA , Simes JJH
Published: September 2010

Extraction of the wood of Eugenia crebrinervis
has yielded ellagic acid and a triterpenoid
fraction composed of a 1 : 1 mixture of asiatic acid
and arjunolic acid. Extraction of the wood of Eugenia gustavioides
has given a mixture of triterpenoid acids (2.7 % of
the dry weight of the wood) of which crategolic acid
(c.1%) is the principal constituent; other major constituents are asiatic acid and arjunolic acid,
while oleanolic acid, ursolic
acid and 2α-hydroxyursolic acid are minor constituents.In both Eugenia species the
α-amyrin component occurs with the corresponding
β-amyrin analogue giving a mixture separable
only with difficulty; use has been made of the previously described
chlorination procedure1 to enable comparatively easy isolation of the α-amyrin component.
Preparation and metal complexes of 2,2'-Pyridil Bis(2''-pyridyl)hydrazone
Authors: Black DSC , Hartshorn AJ , Murray KS
Published: September 2010

The title compound (diphy) has been prepared from 2,2'-pyridil and
2-pyridylhydrazine and behaves as a quadridentate chelating agent with
nicke1(11), copper(11), zinc(11) and cadmium(11) salts. The
mono-(2-pyridylhydrazone) of 2,2'-pyridil (pmpy) is
also described, together with its nickel(11) complex perchlorate.
The synthesis of Per-O-benzyl-α-D-galactosyl and -α-L-fucosyl bromides
Authors: James K , Stick RV
Published: September 2010

The title compounds have
been synthesized by per-O-benzylation of the appropriate allyl glycosides, followed
by removal of the allyl group and replacement by bromide.
Structures of simple anions from ab initio molecular orbital calculations
Authors: Radom L
Published: September 2010

Ab initio molecular orbital theory with the minimal STO-3G and split-valence
4-31G basis sets is used to obtain geometries of 18 anions:OH-,
NH2-, HF2-, BH4-,
BF4-, C22-, CN-, NCN2-,
N3-, NO2-, NO3-,
0CCO2-, CO32-, HCOO-, CH3COO-,
C2O42-, C4O42-
and C(CN)3-. The theoretical results are compared with
experimental results from the literature. The STO-3G basis set performs
somewhat worse for anions than for neutral molecules. On the other hand, the
4-31G basis set gives good results and predicts bond lengths to within 0.02�
for all the molecules considered. Limited information on bond angle predictions
suggests that these are of comparable quality to those for neutral molecules.
The tricyanomethanide ion is predicted to be planar.
Nitrones and oxaziridines. XIV. Reaction of 1-Pyrroline 1-oxides with phosphoranes and phosphonate carbanions
Authors: Black DSC , Davis VC
Published: September 2010

The reactions of diethyl [ethoxycarbonyl(sodio)methyl]phosphonate and ethoxycarbonylmethylene-triphenylphosphorane
with 1-pyrroline 1-oxides afford 1-azabicyclo[3,1,0]hexanes andethoxycarbonyl-
methylidenepyrrolidines, but the reaction is not
general for other phosphonate or phosphinoxy
carbanions.
The alkaloids of Elmerrillia papuana (Magnoliaceae) : Structure and synthesis of elmerrillicine
Authors: Cleaver L , Nimgirawath S , Ritchie E , Taylor WC
Published: September 2010

From the bark of Elmerrillia papuana (Schltr.) Dandy (Magnoliaceae)
were isolated the known alkaloids liriodenine, norushinsunine (as its diacetyl
derivative) and N-methylushinsunine iodide, together
with a new alkaloid, elmerrillicine (as its monoacetyl and diacetyl
derivatives). By spectroscopic methods elmerrillicine
was deduced to be 3-methoxy-l,2-methylenedioxy-6-demethylaporphin-11-ol, This
structure was confirmed by a synthesis by the standard route involving a Pschorr reaction and by a photochemical synthesis in which
a dehydroaporphine was an intermediate.
Studies with Bicyclo[2,2,2]octenes. V. The behaviour of a series of Bicyclo[2,2,2]octenyl carbinols in acidified methanol
Authors: Gregson RP , Mirrington RN
Published: September 2010

A detailed account of the
synthesis of three related bicyclo[2,2,2]octenyl carbinols (3),(4) and (5) and
their behaviour in acidified methanol is presented. Seventeen different
compounds which are intermediates of final stable end products have been isolated
and characterized. In each case the products of acid-catalysed isomerization
can be explained by postulating rearrangements involving stabilized carbonium
ions.
6α- and 6β-Acetic acid derivatives of Cholest-4-en-3-one and Pregn-4-ene-3,20-dione
Authors: Collins DJ , Horn CM , Welker VJ
Published: September 2010

The methyl esters of the
6-epimers of 3-oxocholest-4-en-6-ylacetic acid, and of 3,20-dioxopregn-4-en-6-ylacetic
acid, have been synthesized from 5α,6-epoxy-3,3-ethylenedioxy-5α -cholestane and 5α,6-epoxy-3,3,20,20-bisethylenedioxy-5α
-pregnane, respectively, via the corresponding 5α-hydroxy-
6β(prop-2-enyl) derivatives.
The formation of iron(III) oxide hydroxides from iron(II) oxalate
Authors: Atkinson RJ
Published: September 2010

FeC2O4,2H2O(s)
suspensions in sodium hydroxide solutions were oxidized by a fast air-bubble
flow at room temperature until complete reaction had occurred. With amounts of NaOH in the range OH/Fe initial mole ratio ≤1.0, the
reaction is

FeC2O4, 2H2(s)+ OH-(aq)+ �O2(g) → ⅔γFeOOH(s)+1/3Fe(C2O4)33-(aq)+13/6H2O

With OH/Fe mole ratio ≥
2.0 the reaction is

FeC2O4, 2H2(s)+ 2OH-(aq)+ �O2(g) → αFeOOH(s)+(C2O4)33-(aq)+ 5/2 H2O

Mixtures of goethite (α-FeOOH) and lepidocrocite (γ-FeOOH) form at intermediate OH/Fe mole ratio. The oxidation
process occurs in a solid-phase intermediate product. Comparisons with similar
oxidations of iron(11)sulphate solutions showed that γ-FeOOH formation was favoured and α-FeOOH
formation inhibited in the iron(11) oxalate oxidation. These differences are
related to pH and dissolved iron concentrations.
Dehydration studies of 8a-Methyldecahydronaphthalen-4a-ols
Authors: Coxon JM , Lindley NB
Published: September 2010

The H2SO4-HOAc-Ac2O-catalysed
dehydration of the epimeric 8a-methyldecahydronaphthalen-4a- ols has been shown to occur regiospecifically
without skeletal or methyl migration, by loss of a proton syn to the departing
anionic moiety. The results are interpreted in terms of the intermediacy of a
tight ion pair where the oxy anion acts as the base in the removal of the
proton. The introduction of an

electron-withdrawing substituent at Cl, syn
to the 8a-methyl of 8a-methyl-trans-decahydronaphthalen-4a-ol,
allows methyl migration to compete with 1,2-elimination.
Volatility studies of metal chelates. II. Gas chromatographic properties of vanadium β-diketonates
Authors: Dilli S , Patsalides E
Published: September 2010

The gas chromatographic
elution behaviour is reported for a total of 16 vanadium(111) and oxovanadium(1V) fluorinated β-diketonates
on a column consisting of a lightly loaded, non-polar stationary phase and
diatomite support. The superiority of the vanadium(111) chelates is shown to include
electron-capture detection. Detection limits of 14 chelates are given for the
flame ionization detector. Separation of the two oxidation states of a metal by
gas-liquid chromatography is demonstrated for the first time.
The zinc gluconate system
Authors: Roller PW , Pickering WF
Published: September 2010

A study of the zinc
gluconate system has shown that, in solutions of pH <6, one, two or four
gluconate ions can be coordinated to the metal ion. Above pH 6 a gel is formed
[formula Zn2(glH4)(OH)3,xH2O, pKsp'28];
this slowly transforms into Zn(OH)2 at pH >7. Formation of
soluble zincates occurs at pH >10. Two solid compounds [Zn(glH4)2
3H2O and Zn2(glH3)(OH)2] have
been isolated and subjected to spectral and thermal examination.
The stereochemistry of organometallic compounds. XIV. trans-Effects in the 13C N.M.R. spectra of Dicarbonyltriphenyl-phosphine- and -arsine-(arene)chromium compounds
Authors: Jackson WR , Pincombe CF , Rae ID , Rash D , Wilkinson B
Published: September 2010

The 13C chemical
shifts of some triphenyl-phosphine and -arsine
dicarbonyl(arene)chromiums
are reported. The shifts are discussed in terms of a deshielding effect on the arene ring carbons trans to the Group 5 atom in the
preferred conformations of these molecules.
The acid-catalysed rearrangement of 28-norlupenes
Authors: Baddeley GV , Fookes CJR , Nigam SK
Published: September 2010

The acid-catalysed
isomerization of the mixture of olefins (4), (7) and (8), obtained from the
oxidative decarboxylation of lupan-28-oic acid (1), leads to the
tetrasubstituted olefin (9).
Colouring matters of the Aphidoidea. XLI. The phospholipids of Eriosoma lanigerum (Hemiptera : Insecta)
Authors: Cameron DW , Drake CB
Published: September 2010

Whereas triglycerides of
the woolly aphid E. lanigerum are rich in myristate and sorbate residues, the phospholipids
contain chiefly oleate, linoleate and stearate. In agreement with other aphid
work, there is significantly more phosphatidyl
ethanolamine than phosphatidyl choline.
Herbicides. II. Crystal Structure of 2,4,5-T (2,4,5-Trichlorophenoxyacetic Acid)
Authors: Smith G , Kennard CL , White A
Published: September 2010

The crystal structure of
2,4,5-T was determined by the symbolic addition method. 1741 reflections, of
which 1326 were considered observed, were collected on a four-circle
diffractometer. Crystals are triclinic, Pī, with
z = 2, in a cell of dimensions: a 1089.5(6), b 684.8(3), c 683.8(3) pm, α
81.33(4)�, β 78.90(4)�, γ 83.04(4)�. The structure was refined by
least squares to R 0.068. The two molecules are hydrogen-bonded [O...H-O
268.9(7) pm] through their carboxylic acid groups forming a cyclic dimer in a similar
manner to 2,4- dichlorophenoxyacetic acid (2,4-D).1
However, the planes of the benzene ring and the carboxyl group are 4.15� away
from being coplanar, a fact which is markedly different from that observed in
2,4-D (85.23�) but similar to that observed in the substituted aromatic
carboxylic acids. The result of this is a dimer with all atoms except those in
the methylene group lying approximately in a plane.
New routes to 7-Alkyl-10-methylnaphtho[1,2-g]pteridine-9,11(7H,10H)-diones and 12-Alkyl-9-methylnaphtho[2,1-g]pteridine-8,10(9H,12H)-diones from naphthols
Authors: Gumbley SJ , Main L
Published: September 2010

2-(1-Nitronaphthalen-2-ylamino)ethanol,
prepared from 2-methoxy-1- nitronaphthalene and
2-aminoethanol,can be reduced to 2-(1- aminonaphthalen-2-ylamino)ethanol which
condenses with 1-methylalloxan to give 7-(2-hydroxyethyl)-10-methylnaphtho[1,2-g]pteridine- 9,11(7H,10H)-dione.��� 12-(2-Hydroxyethyl)-9-methylnaphtho[2,1-g]pteridine-8,10(9H,12H)-
dione can be prepared by a similar reaction sequence from 1-methoxy-2- nitronaphthalene.
Cobalt(III) and chromium(III) complexes of N-(2-Aminoethyl)salicylaldimine: Crystal structure and resolution of the racemates
Authors: Benson TH , Bilton MS , Gill NS
Published: September 2010

The cobalt(III) and
chromium(III) complexes of N-(2- aminoethyl)salicylaldimine, M(salen)2+, have
been resolved into their optical isomers. The electronic absorption spectra and
circular dichroism spectra of the complexes have been measured for solutions in
water and ethanol and assignments for the absorption bands proposed. The crystal
structure of the racemate, Co(salen)2I,H2O, has been
determined from three-dimensional X-ray diffraction data. The crystals are
monoclinic, space group P21/c with a 18.386(1), b 10.216(1), c
12.004(1) Ǻ, β 109.87(1)°, Z 4. The structure was solved by the
heavy- atom method and refined by least-squares techniques to R 0.098 for 4493
reflections (63.5% observed). The cobalt atom is octahedrally coordinated by
two tridentate ligands in the meridional configuration.
Synthesis of perbromobenzoic acids and perbromobenzenes from aromatic carboxylic acids by permercuration and bromodemercuration
Authors: Deacon GB , Farquharson GJ
Published: September 2010

Permercuration of the
benzoic acids XC6H4CO2H (X = o-Me, F, Cl, or Br; m- Me, F, Cl, Br, CF3,
NO2 or OMe; or p-Me, F, Cl, Br, CF3 or NO2) and 2,6- X2C6H3CO2H
(X = Me, Cl, or Br) with molten mercuric
trifluoroacetate at c. 180-245° followed by bromodemercuration gave the
corresponding perbromobenzoic acids XC6Br4CO2H
or 2,6-X2C6Br3CO2H, together with
the corresponding perbromobenzenes C6Br5X or m-X2C6Br4
which were formed owing to decarboxylation under permercuration conditions.
Similar treatment of the acids XC6H4CO2H (X =
o-NO2, CF3, or OMe; or p-OMe) and 2,6-F2C6H3CO2H
gave only the appropriate perbromobenzenes. Possible mechanisms for
permercuration induced decarboxylation are proposed on the basis of the effect
of substituents on yields of perbromobenzoic acids and perbromobenzenes.
Decarboxylation occurs more widely under permercuration conditions than on
pyrolysis of mercuric carboxylates. Regiospecific mercuration meta to the
carboxyl group and not decarboxylation occurred on thermal decomposition of mercuric
p-methoxybenzoate.
Hydrophobic interaction between the bile acids and long-chain alkyltrimethylammonium ions: A model for cholesterol-lipid interaction
Authors: Oakenfull DG , Fenwick DE
Published: September 2010

Ion-pair association
constants (K) for long-chain alkyltrimethylammonium salts of the bile acids
have been measured conductometrically at 25°C in 0.1 mole fraction
ethanol-water. The free energy of ion-pair formation (ΔG°ip = -RT
ln K) was separated into its electrostatic and
hydrophobic components by examining the effect of alkyl chain length on
ΔG°ip. The electrostatic contribution was the same for each
bile acid and agreed with the value previously obtained for long-chain
alkyltrimethyl-ammonium carboxylate ion pairs under the same conditions. The
hydrophobic contribution depended on the structure of the bile acid and varied
linearly with the number of OH groups. (There are no significant attractive
forces between non-polar groups in water. Hydrophobic interaction is the tendency
of non-polar groups to associate because this minimizes their energetically
unfavourable contact with water.) Our results support current theories of
hydrophobic interaction and give an indication of the extent of the effect of
neighbouring polar groups on hydrophobic interaction. Extrapolation to zero OH
groups gave an estimate of the free energy of hydrophobic interaction (ΔG°HI)
between an alkyl chain and a cholesterol analogue (a steroid ring system with a
single polar substituent). This value of ΔG°HI was -2.77 kJ mol-1
per methylene group compared with -2.24 kJ mol-1 per methylene group
for hydrophobic interaction between two alkyl chains. (The small difference is
explained by the greater number of water molecules displaced in an
alkyl-steroid contact than in an alkyl-alkyl contact.) This result conflicts
with claims made by other workers that the steroid-alkyl interaction is weak,
or that cholesterol is less hydrophobic than its structure indicates.
Long-range coupling and conformation in some thienylmethylene and furfurylidene derivatives
Authors: Brophy GC , Newcombe PJ , Norris RK
Published: September 2010

The p.m.r,
spectra of 12 2-thienylmethylene and furfurylidene derivatives are reported.
The average conformation about the Ar-CHXY bond is
deduced from the magnitude of the meta (and ortho) long-range benzylic coupling
constants. In thiophens, conformations in which the benzylic hydrogen is in or
near the plane of the aromatic ring and anti to the ring sulphur are preferred.
In furans the hydrogen-in-plane conformations are again favoured. The signs of
the meta and ortho benzylic coupling constants have been determined and are
positive and negative respectively with respect to the vicinal coupling
constant J3,4.
The use of rotating cylinders in the study of metal displacement (cementation) reactions
Authors: Higgs JM , Lawson F , Power GP , Ritchie IM
Published: September 2010

The use of rotating zinc
cylinders in a kinetic study of the diffusion- controlled displacement reaction
between zinc metal and copper(II) ions is reported. It is found that the results
are a good fit to the empirical equations which have been previously established
for mass transport to a rotating cylinder. Some limitations to the technique
are noted, including an effect which becomes more pronounced as the cylinder
length is reduced.
Dipole moments, Kerr constants and other properties of acetoacetic ester and acetylacetone
Authors: Cusiter MA , Le Fevre RJW , Millar D , Pierens RK
Published: September 2010

The proportions of the keto and en01 isomers of ethyl acetoacetateand of acetylacetone incyclohexane,
carbon tetrachloride and benzene have been determined by n.m.r. spectroscopy, and expressed as
functions of the solute concentrations. Routine methods sufficed for all other observations, except
those of electric birefringence, which needed to be examined by a pulsed-voltage technique. The
dipole moments and molar Kerr constants so obtained are analysed to provide corresponding data
for the separate tautomers. Possible conformations of these keto and en01 molecules can be inferred
from considerations involving known bond polarities and anisotropic polarizabilities.
Catalysed gas phase decompositions. XXXI. 2,2-Dimethoxypropane and formic and propionic acids
Authors: Stimson VR , Tilley JW
Published: September 2010

Formic and propionic acids
catalyse the decomposition of 2,2- dimethoxypropane into isopropenyl methyl
ether and methanol in homogeneous, molecular reactions at 274-334 and 335-389�C
with rate constants:

������������������ k2 = 1010.62exp(-94030/8.314T)
s-1 ml mol-1

������������������ k2 = 1012.44exp(-124240/8.314T)
S-1 ml mol-1

respectively.��� Carboxylic acids appear to be generally
effective as catalysts, and with this substrate the rate order is:������� ���������������� HBr
> CF3COOH > HCl >> HCOOH >
CH3COOH ≈ C2H5COOH
The isomeric distribution of amino acids produced in γ-radiolytic carboxylation of amines
Authors: Davison A , Barker NT , Sangster DF
Published: September 2010

Amino acids produced in the
γ-radiation-initiated carboxylation of ethylamine, propylamine, isopropylamine,
butane-1,4-diamine and pyrrolidine have been characterized. Isomeric
distributions of amino acids from each amine have been determined. These distributions
reflect the isomeric distribution of amine radicals present, and hence yield
information on the initial site of hydrogen abstraction by radiolytically
generated hydroxyl radicals. Factors influencing the sites of abstraction are
discussed.
Studies on Chloroplast Membranes. I. 13C Chemical Shifts and Longitudinal Relaxation Times of Carboxylic Acids
Authors: Johns S , Leslie D , Willing R , Bishop D
Published: September 2010

The 13C chemical
shift and longitudinal relaxation time (T1) of the individual carbon
atoms in a series of carboxylic acids in CDCl3 solution have been
determined. Substituent shift parameters have been derived from the chemical
shift data. The relaxation times have been interpreted in terms of increasing
segmental motion along the methylene chains of the carboxylic acid molecules
which are associated at the carboxylic acid groups in the form of inverted
micelles. Differences in the segmental motion between saturated and unsaturated
carboxylic acids are rationalized on the grounds of intermolecular interactions
between adjacent molecules in the inverted micelle structures.
Novel 4-styrylflavans from gum accroides
Authors: Camarda L , Merlini L , Nasini G
Published: September 2010

Extraction of gum accroides
(probably derived from trees of the Xanthorrhoea genus) afforded 4?-
hydroxy-4-(4-hydroxyphenylethenyl)-7- methoxyflavan and 4?-hydroxy-4-(4-hydroxyphenylethenyl)-
5,7- dimethoxyflavan, which belong to a new class of flavonoids. (2S)-4?-
Hydroxy-7-methoxyflavanone and the new (2S)-3?,5,5?-trihydroxy-4?,7- dimethoxyflavanone
have been also isolated, together with 2?,4- dihydroxy-4?-methoxychalcone and
2?,4,4?-trihydroxychalcone.
Synthesis of reactive dyes for wool employing isocyanate bisulphite adducts
Authors: Kirkpatrick A , Maclaren JA
Published: September 2010

Syntheses of azo dyes which
incorporate a bisulphite-isocyanate adduct as a ?masked? reactive group are
described. Two general methods are used. One is based on couplings with
diazotized sodium 4- aminobenzylaminooxomethanesulphonate
(2). The other is achieved by coupling aromatic dia- zonium salts with sodium 6-(3?- dimethylaminophenylureido)hexylaminooxomethanesulphonate (4). The synthesis of (4)
involves monofunctional addition of an arylamine to
hexamethylene diisocyanate.
Oxidation of alkyl groups accompanying the Zinin reduction of nitroarenes
Authors: Burgess DA , Rae ID
Published: September 2010

p-Aminobenzaldehydes have
been prepared from several nitroxylenes and trimethylnitrobenzenes by reaction
with aqueous alcoholic sodium polysulphide. The oxidation of the methyl group
accompanying the Zinin reduction proceeds most readily when the nitro group is
unhindered.
Nitrones and oxaziridines. XVIII. Synthesis and photochemistry of 2-Acyl-1-pyrroline 1-Oxides
Authors: Black DSC , Boscacci AB
Published: September 2010

The preparations of
2-benzoyl-5,5-dimethyl-(4a), 2-benzoyl-5,5- dimethyl-4-phenyl-(4b) and
2-formyl-5,5-dimethyl- (13a) 1-pyrroline 1- oxide via the corresponding oximes
are described. These oxo nitrones undergo photolysis mainly to 5,5-dimethyl-
and 5,5-dimethyl-4-phenyl- pyrrolidin-2-one [(14a) and (14b)]. ��� 2-Benzoyl-5,5-dimethyl-1-pyrroline (15) is
also a product of irradiation of (4a) and affords the lactam (14a) on reaction
with peracid. 2-Benzoyl-5,5-dimethyl-3-oxo-1-pyrroline 1-oxide (9) and its dioxime
(8) are also described.
Kinetic studies of the reactions of glutathione with aromatic compounds
Authors: Gan L
Published: September 2010

Kinetic results for the
non-enzyme-catalysed reaction of glutathione and 1-chloro-2,4-dinitrobenzene are
reported. Positive kinetic salt effects are observed in the presence of sodium
chloride. The effect is more pronounced at higher temperature. Glutathione also
reacts with 1,3,5-trinitrobenzene to form a Meisenheimer complex.
Reactions over supported metal catalysts. IV. The stereochemistry and mechanism of hydrogenolysis of some propellanes
Authors: Gooding KR , Jackson WR , Pincombe CF , Rash D
Published: September 2010

Hydrogenolysis of the
propellanes tricyclo[4,4,1,01,6]undecane and tricyclo[4,3,1,01,6]decane
gives similar stereochemical ratios of products for reactions carried out
either in acetic acid solution with a platinum oxide catalyst or over supported
metal catalysts in the vapour phase. Almost equal amounts of cis- and trans-1- methylbicyclo[4,4,0]decanes
are formed from the former, whereas cis-1- methylbicyclo[4,3,0]nonane
predominates from reaction of the tricyclodecane. It is proposed that reaction
of the highly strained propellanes over metal catalysts involves metal
insertion reactions even for reactions over platinum in acetic acid solution.
Deuterium incorporation studies are described which support this proposal.
Vinylindenes and some heteroanalogues in the Diels-Alder reaction. III. Benzoquinone, 1,4-Naphthoquinone and Benzo[b]thiophen 1,1-Dioxide as dienophiles
Authors: Bergamasco R , Porter QN
Published: September 2010

3-Vinylindene gives high
yields of adducts with 1,4-benzoquinone, 1,4- naphthoquinone, and
benzo[b]-thiophen 1,1-dioxide. The structures and stereochemistries of the
adducts are confirmed by p.m.r. and mass
spectrometry. The effects of various oxidation procedures on the 1,4- naphthoquinone
adduct are described; no skeletal rearrangement accompanies oxidation with
oxygen in base. Some adducts of 34sopropenylindene and 2-methyl-3-vinylindene
are also described.
Fluorine magnetic resonance studies. IV. α,2-Difluoro- and α,α,2-Trifluoro-toluenes
Authors: Burgess DA , Rae ID
Published: September 2010

Fluorine-fluorine coupling
over four bonds has been observed in the 19F N.M.R. spectra of three
α,2-difluorotoluenes and three α,α,2- trifluorotoluenes.
Hydroxyisothiazoles. I. Preparation of 3- and 5-isothiazolinones by nucleophilic displacement of isothiazole sulphones
Authors: Davis M , McVicars JL , Paproth TG
Published: September 2010

Heating of
4-aryl-3,5-bis(alkylsulphonyl)isothiazoles with sodium hydroxide solution under
reflux affords in good yield a readily separable mixture of the
3-hydroxy-5-alkylsulphonyl and 5-hydroxy-3- alkylsulphonyl compounds.
Electron and nuclear spin relaxation in S = ½ paramagnetic transition-metal complexes
Authors: Doddrell DM , Pegg DT , Bendall MR , Gregson AK
Published: September 2010

Nuclear spin relaxation in
some S = 1/2 paramagnetic transition-metal complexes is considered. If
rotational reorientation dominates the electron and nuclear spin relaxation
processes current theoretical treatments of spin relaxation provide an adequate
description of the spin relaxation. However, there are many complexes where
other time processes appear to be important. It is suggested that dynamic Jahn-
Teller effects may be operative in Ru(acac)3. ��� It is shown that the rotational Van Vleck
mechanism is effectively the same relaxation mechanism as the so-called
?g-tensor? process. Although the Van Vleck mechanism is a useful reformulation
of the same problem, it appears that this mechanism or any other rotationally
induced electron spin relaxation process cannot adequately describe the nuclear
relaxation times in a variety of para-magnetic transition-metal complexes.
The assignment of the carbon-13 N.M.R. spectra of Westphalen-rearranged steroid olefins with the aid of the lanthanide shift reagent Eu(fod)3
Authors: Coxon JM , Hoskins PR , Ridley TK
Published: September 2010

Shifts induced by Eu(fod)3
in the 13C N.M.R. spectra of 5-methyl-19-nor-
5β-cholest-9(10)-en-4β- and -6β-ols are used in conjunction with
off- resonance proton decoupling and substituent effects to assign the 27
carbon resonances of the rearranged 5-methyl-19-nor-5β-cholest-9(10)- ene
steroid skeleton.
Crystal structure of Tetracyclo[5,3,1,12,6,04,9]dodecane (iceane)
Authors: Hamon DPG , Raston CL , Taylor GF , Varghese JN , White AH
Published: September 2010

The crystal structure of
the title compound, C12H18, has been determined at 295 K
by X-ray diffraction and refined by full-matrix least squares to a residual of
0.049 for 216 ?observed? reflections; molecular geometry has been corrected for
the effects of thermal motion using a rigid body approximation. Crystals are
hexagonal, P63/m, a = 6.582(1), c = 11.843(3) Ǻ, Z = 2, the molecules
occupying a hexagonal close- packed array.
New synthesis of 1,2-benzisoxazole derivatives
Authors: Kalkote UR , Goswami DD
Published: September 2010

N-Phenylsalicylohydroxamic
acids, salicylohydroxamic acids, o- hydroxyacetophenone oximes and salicylaldoximes gave the
corresponding N-phenyl-1,2-benzisoxazol-3(2H)-ones, 1,2-benzisoxazol-3-ols,
3-methyl- 1,2-benzisoxazoles and 1,2-benzisoxazoles when treated with thionyl
chloride in the presence of dry pyridine in anhydrous ether at 0�C.
The vibrational spectra of some phenylmercuric halides and diphenylmercury
Authors: Barraclough CG , Berkovic GE , Deacon GB
Published: September 2010

The Raman spectra of
phenylmercuric chloride, phenylmercuric bromide, phenylmercuric iodide and
diphenylmercury, and the infrared and Raman spectra of diphenylmercury in
solution are reported. Using the previously reported infrared spectra of these
compounds, vibrations were assigned, normal coordinate analyses were performed
and frequencies were calculated using a valence force field. Good agreement was
achieved between observed and calculated frequencies. The structure of
diphenyl-mercury in solution is discussed.
Carbon-13 N.M.R. studies of carbocations. Determination of σ+ortho constants from 13C spectra of benzhydryl cations
Authors: Kelly DP , Spear RJ
Published: September 2010

Carbon spectra of a range
of 2- and 4-substituted benzhydryl cations have been measured in super acid at
variable (low) temperatures. In the 4-substituted benzhydryl cations the
chemical shift of the para carbon in the unsubstituted ring [δ(C4?)]
proves to be an excellent probe for changes in charge density at the cationic
carbon, as shown by its correlation with σp+ (r
0.990). Measurement of δ(C4?) for the 2- substituted benzhydryl cations
provides a direct measure of σ0+ for side-chain benzene
derivatives; these values are OMe -0.59, Me -0.10, F
0.19, Cl 0.26, Br 0.29 and CF3 0.69.
On the reliability of fluorescence decay data
Authors: Hinde AL , Selinger BK , Nott PR
Published: September 2010

The confidence with which
fluorescence decay data can be interpreted is dependent upon the accuracy and
precision of these data. This dependence is especially critical when more than
one exponential is involved in the decay.1,2 Unfortunately decay
curve parameters have often been presented without any indication of either
their accuracy or precision. An analysis is presented which suggests that the
covariance ellipsoid is the most satisfactory statistic with which to define
the precision.
The crystal structure of two cobalt(I) complexes containing the polyphosphine ligands PhP{(CH2)nPPh2}2 (n = 2, 3)
Authors: Mason R , Scollary GR
Published: September 2010

X-ray diffraction analysis
of the two complexes [CoPhP{(CH2)3PPh2}2P(OMe)3CO] BF4,thf and [CoPhP{(CH2)2PPh2}2{P(OMe)3}2] BF4 are reported.
Crystals of the first complex are triclinic, space group Pī
with a 14.310(1), b 11.080(2), c 16.099(3) Ǻ, α 68.30(2), β
90.78(2), γ 75.04(1)�. The structure analysis has been based on 2964
independent reflection intensities (Cu Kα
automatic diffractometry) to give R 0.11. The second complex is monoclinic,
space group P21/c, with a 13.18(4), b 11.49(3), c 29.66(6) Ǻ,
β 101.59(2)�. Refinement by least squares has converged to R 0.093 for the
2256 independent reflection intensities, observed by Mo Kα automatic
diffractometry. The preferred stereochemistries of the five-coordinate cobalt
complexes are discussed in relation to the bite angle of the chelating
phosphine.
Circular dichroism of benzylidene derivatives of glycerol and mannitol
Authors: Carman RM , Hawkins CJ , Kibby JJ
Published: September 2010

The c.d. spectra are
reported for a series of benzylidene derivatives of glycerol and mannitol
containing 1,3-dioxolan, 1,3-dioxan and 1,3- dioxepan
ring systems. The signs of the Cotton effects of 1Lb and 1La
transitions of the phenyl chromophore have been rationalized in terms of
recently proposed sector rules for these transitions.
Mixed carboxylate sulphonate esters of glycerol
Authors: Auteri SC , Cameron DW
Published: September 2010

Syntheses of the four mixed
palmitate p-toluenesulphonate triesters of glycerol are described. Syntheses involving
p-toluenesulphonic acid were in some cases accompanied by acyl migration. This was
avoided by the use of p-toluenesulphonyl chloride in pyridine. The products
were analysed by p.m.r. spectra in the presence of europium shift reagent. They
underwent smooth reductive cleavage of p-toluenesulphonate on treatment with
sodium borohydride.
Metal template reactions. XII. Comparison of some chemical and physical properties of dibenzocorromin metal complexes with those of corrins and otherrelated systems
Authors: Black SC , Hartshorn AJ , Horner M , Hunig S
Published: September 2010

Methyl and ethyl
derivatives of cobalt(III) dibenzocorromin complexes have been prepared and
their properties are compared with those of related cobalt alkyls. A comparison
of spectroscopic and electrochemical properties of dibenzocorromin complexes
with those of corrins and related systems is also presented.
Prediction of vapour-liquid equilibrium: Theory, computer techniques and application to permanent gas mixtures at pressures in excess of 5 bar
Authors: Hicks CP , Young CL
Published: September 2010

A technique for calculating
the composition of two coexisting phases in equilibrium at a given temperature
and pressure is described. The method is applicable, in principle, to any
one-fluid model and any two- parameter closed equation of state. The philosophy
of the technique is similar to that used in previous work on critical points.��� Values of (∂G/∂x2)T,P
are calculated for mole fraction compositions ranging from zero to unity in small
steps in order to locate (∂G/∂x2)T,P loops.
Around each loop there is a region of phase separation and the compositions of
coexisting phases are found by the usual equal-area line technique. ��� The use of the method is briefly
illustrated by comparison with the experimental results for simple gas
mixtures. The agreement between theory and experiment is satisfactory.
Addition of bromine to exo-3-Oxa-endo-tetracyclo[3,3,1,02,4,06,8]nonane: Crystal structure of the dibromide
Authors: Johnson BL , Rome DW , White AH , Willis AC
Published: September 2010

Treatment of the title
compound (1) with pyridinium bromide perbromide results in cleavage of the
cyclopropane ring to yield the dibromides (2) and (3). The crystal structure of
dibromide (2) (C8H10Br20) was determined at
295 K from diffractometer data and refined to a residual of 0.054 (1539
reflections, I > 2σ(I)). The crystals are monoclinic, P21/c,
a 12.766(3), b 12.317(2), c 12.056(2) Ǻ, β 103.2(2)�, Z 8.
5-O-Methylhiascic acid, a new tridepside from Australian lichens
Authors: Elix JA , Jayanthi VK
Published: September 2010

The tridepside 5-O-methylhiascic
acid (7) has been isolated from an unnamed crustose lichen and detected in
Parmelia horrescens, Parmelia pseudofatiscens and Parmelia dissecta. The
structure of this compound followed from the spectroscopic data and has been
confirmed by the total synthesis of both 5-O-methylhiascic acid and the isomer,
4-O- methylhiascic acid (6). Diploschistesic acid (21) and 5- hydroxylecanoric
acid (23) were also synthesized.
Crystal structure of (Z)-Cembr-4-ene-15,19,20-triol
Authors: Maslen EN , Raston CL , White AH
Published: September 2010

The crystal structure of
the title compound, CZOH3803 [compound (1) in ref.'], has been determined by
single-crystal X-ray diffraction at 295(1) K and refined by least squares to a
residual of 0.045 for 954 'observed' reflections. Crystals are monoclinic, P2',
a 9.281(2), b 17.798(6), c 6.417(1) A, B 93.81(3)", Z 2. The structure
determination establishes the relative configuration of the chiral centres
within the 14-membered macrocyclic ring and shows the double bond to have the
unusual (Z) configuration.
Photochemical syntheses. XII. Photodimers related to 2-Methoxy-naphthalene
Authors: Teitei T , Wells D , Spurling TH , Sasse WHF
Published: September 2010

Seven naphthalene
derivatives related to 2-methoxynaphthalene form photodimers that are based on
the ring systems (1) and/or (2). Except for the dimers of methyl
6-methoxy-2-naphthoate only head-to-tail dimers have been observed. This
orientation can be related to the charge distributions in the ground states of
the participating molecules if one assumes that pairwise
association occurs before excitation.
Reaction of bisbenzylisoquinoline alkaloids with ceric ammonium nitrate: A new degradative procedure
Authors: Bick IRC , Bremner JB , Cava MP , Wiriyachitra P
Published: September 2010

Ceric ammonium nitrate
cleaved laudanosine (1) quantitatively into veratraldehyde (2) and 6,7-dimethoxy-2-methyl-3,4-dihydroisoquinolinium
ion (3), isolated as the reduced product, 6,7-di-methoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline
(4). The reagent also degraded tetrandrine (5), hernandezine (6) and O-methylmicranthine
(7) in a similar way; the products after reduction were isolated as diamines
[(8), (9) and (10) respectively] and a diol, 3-[4'-
(hydroxymethyl)phenyloxy]-4-methoxybenzyl alcohol (11), in nearly quantitative
yields. When applied to berbamine (12), thalibrunine (13) and tenuipine (14),
this reaction gave good yields of the nitrogen-containing fragments only.
Studies on intramolecular alkylation. IX. The synthesis of tricyclic dienones suitable for the synthesis of 13-hydroxygibberellins
Authors: Blair IA , Ellis A , Johnson DW , Mander LN
Published: September 2010

2-Hydroxy-6-methoxy-1,2,3,4-tetrahydro-2-naphthoic
acid and its 8- methoxy isomer were converted into trichloroacetate and
dichloroacetate derivatives and thence to diazoketones (2), (3), (12) and (13).
The acid-catalysed cyclization of these substrates to the dienones (6), (7),
(16) and (17), respectively, was then studied. The trichloroacetoxy derivatives
gave the best yields of dienones.
Attempts to observe the photocleavage of water in the presence of a ruthenium complex
Authors: Yellowlees LJ , Dickinson RG , Halliday CS , Bonham JS , Lyons LE
Published: September 2010

Attempts to obtain the results
claimed by Whitten et al.1 for the photocleavage of water in the presence
of a ruthenium complex have been unsuccessful. The reaction conditions are
described in detail.
A synthesis of paratose (3,6-Dideoxy-D-ribo-hexose)
Authors: Patroni JJ , Stick RV
Published: September 2010

Deoxygenation at C 6 of
3-deoxy-1,2-O-isopropylidene-α-D-ribo-hexofuranose,
followed by hydrolysis, gave paratose.
Structural and spectral studies of halogeno complexes of Tri- and Tetra-valent ruthenium
Authors: Fergusson JE , Greenaway AM
Published: September 2010

A preparative study of
chloro and bromo complexes of tri- and tetra-valent ruthenium has shown that
the principal ruthenium(III) chloro species, isolated with alkali metal cations
from HCl solution, are [RuCl6]3-
and [RuCl5H2O]2-. But in the case of the ruthenium(III)
bromo system the only anionic product isolated was [Ru2Br9]3-.
The dinuclear anion was also reversibly oxidized in solution to the
ruthenium(IV) species [RuBr6]2-. Structural studies, by
X-ray powder diffraction, have highlighted the close structural similarity of K2
[RuBr6] and K3 [Ru2Br9]. A Ru-Ru bond is proposed for the dinuclear unit. Both X-ray
structural and infrared studies have been carried out on the complexes
isolated.