bluuebunny/crossref_metadata_2025 huggingface dataset:
VESCF-MO studies of molecules containing atoms from the second row of the Periodic Table. I. The general problem
Authors: Brown RD , Peel JB
Published: September 2010

As a preliminary step in
the development of a satisfactory molecular-orbital treatment of molecules
incorporating second-row atoms, the VESCF molecular-orbital method is
reconsidered, particularly with respect to evaluation of basic parameters. Appropriate methods of
deriving valence-state ionization potentials, resonance integrals, monocentric and bicentric coulomb
repulsion integrals, and monocentric exchange
integrals are considered. The particular problem of properly treating 3d-orbitals is examined and the use of Burns's rules for
evaluating orbital exponents is suggested. Since the efficacy of the
various procedures depends upon obtaining reliable molecular wave functions, a
brief review is given of the kinds of experimental data that will be used in
Part 11 to test the VESCB wave functions.
Spectrum of azulene. IV. Rotational analysis of the 0-0 band of the 3500 Ǻ transition
Authors: McHugh AJ , Ramsay DA , Ross IG
Published: September 2010

The bands of the 3500 Ǻ
transition of azulene-do and azulene-ds show two unequal peaks 2.3 cm-l
apart, followed by closely spaced fine structure. These bands have been
analysed as type A bands of a planar, prolate
asymmetric top. Rotational constants for both molecules in the excited state
have been determined. The fine structure is due
to multiple line coincidences in the high-J, low-K region of the qP branch. To each multiple line can be
attributed a running number n = J+m, where m = J-K-1.
Given sufficient resolving power, such "lines" should be rather
commonly observed in type A and type B bands of large, planar, prolate molecules.
The heats of solution of alcohols in water
Authors: Alexander DM , Hill DJT
Published: September 2010

A new calorimeter has been
developed and the enthalpy of solution of methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, and 2- methylpropan-2-ol,
in water to low concentrations, measured between 5� and 35�. In all cases, the
results can be adequately represented by a quadratic dependence of heat of
solution on temperature. The results have been compared qualitatively with the
data for the hydrocarbons.
Helix to coil transition in poly-L-amino acids. II. N.M.R. study of model compounds and Poly-γ-benzyl-L-glutamate
Authors: Bradbury JH , Fenn MD
Published: September 2010

The proton magnetic
resonance spectroscopy of simple amides and poly-L- amino acids has been
investigated with particular reference to the question of charging of the amide
group in strong acids. It is found that the downfield chemical shift of the
α-CH resonance of poly-γ- benzyl-L-glutamate (PBG) which accompanies
the helix to coil transition can be conveniently divided into two parts on the
basis of experiments with model systems. The first is due to the collapse of
the helix to an uncharged random coil and the second represents the charging of
the amide groups of the random coil.

For PBG samples of low molecular weight,
two α-CH resonances are observed due to residues in helical (uncharged)
and random-coil (charged) forms. The rate of exchange between them is of the
order of 400 sec-1. The proton resonances of the NH proton, COOH
proton of the acid, and α-CH proton of dichloroacetic acid (DCA) are shown
to be less useful than the α-CH proton.

A critical evaluation has been made of all
the evidence relevant to the charging of the amide group of polypeptides in
mixtures of non-interacting solvents and organic acids e.g. trifluoroacetic
acid (TFA) and DCA. It is concluded that viscosity, infrared, dielectric
constant, electric birefringence, and conductivity studies give overwhelming
support to the concept of charging. Nuclear magnetic resonance, circular
dichroism, and optical rotatory dispersion are less sensitive indicators of
small amounts of charging, and hence studies should be made with samples of low
molecular weight (where there is a greater fractional degree of charging). Such
studies made here by n.m.r. methods give strong support for charging.

The features of the flexible helix model
first proposed in Part I are delineated. It consists of helical segments
separated by short, charged random-coil breaks at both ends and in the interior
of the molecule. Although elaborated in some detail for the case of PBG, it is
likely to occur quite generally for those polypeptides which are soluble in
organic solvents and undergo the helix to coil transition.
A new synthesis of phenanthroindolizidine
Authors: Chauncy B , Gellert E , Trivedi KN
Published: September 2010

(�)-Phenanthro[9,10-f]indolizidine
(I), the basic skeleton of the Tylophora alkaloids, was synthesized by a
modification of the method used for the synthesis of cryptopleurine.
Transition metal complexes of dithioacetylacetone and diselenoacetylacetone: syntheses, properties, and infrared spectra
Authors: Barraclough CG , Martin RL , Stewart IM
Published: September 2010

The synthesis and
properties of some cobalt(II) and nickel(II) complexes of dithioacetylacetone
and diselenoacetylacetone are described. Unlike the corresponding
acetylacetonates, the cobalt and nickel complexes are square-coordinated
monomers with ground states of spin S = 1/2 and S = 0, respectively. For
divalent nickel, the isolation of a mixed complex containing one
monothioacetylacetonate and one dithioacetylacetonate bidentate ligand
completes the NiS2O2, NiS3O, NiS4
series of diamagnetic monomers.

� A
tentative mechanism is proposed for the course of the reaction which leads to
these compounds under the experimental conditions first formulated by Martin
and Stewart. The infrared absorption spectra have been assigned on the basis of
a normal coordinate analysis taken in conjunction with the unusually favourable
circumstances offered by a closely related series of square-coordinated
monomers [Cu(acac)2], [Co(SacSac)2], [Ni(SeacSeac)2].
Activity coefficient assumptions in the determination of association constants. V. Association of thallium(I) bromide from solubility measurements
Authors: Childs CW , Panckhurst MH
Published: September 2010

Measurements are reported
of the solubility of thallium(I) bromide in aqueous solutions of potassium
bromide, sodium perchlorate, barium bromide, and of mixtures of sodium bromide
and sodium perchlorate and of sodium bromide and sodium acetate at 25�. The measurements
are used to test the merits of two types of ionic activity coefficient
expressions, one assuming specific interactions between free ions and the other
not. It is shown that neither expression can describe our results adequately,
in contrast to previous solubility results with thallium(I) chloride for which
the specific interaction expression was adequate.
Schiff base equilibria. VII. Formation and distribution of N-(β-Hydroxyethyl)salicylideneimine
Authors: Green RW , Sleet RJ
Published: September 2010

The formation constant and
pK of the Schiff base N-(8- hydroxyethyl)salicylideneimine in aqueous solution
at 25� have been determined spectrophotometrically to be 5.01 x 103
and 11.4 respectively. These equilibrium constants have been used to account
for the distribution of the imine between water and chloroform.
Synthesis and reactions of Di- and Tetra-hydrobenz[b]indolizines
Authors: Teitei T , Dalton LK
Published: September 2010

Treatment of 1-(4?,4?-diethoxybutyl)-3-methoxycarbonylindole with ethanolic
hydrogen chloride gives in high yield 9-chloro-10-
methoxycarbonyl-6,7,8,9-tetra-hydrobenz[b]indolizine which is readily converted
into the 6,7-dihydro compound and the fully aromatic 10- methoxycarbonylbenz[b]indolizine.
Substitution and addition reactions of these compounds have been studied. A
mechanism for the formation of the chlorotetrahydrobenz[b]indolizines
is discussed.
Constituents of Eupomatia species. The structure and synthesis of eupomatene, a lignan of novel type from Eupomatia laurina R. Br
Authors: McCredie RS , Ritchie E , Taylor WC
Published: September 2010

The bark of Eupomatia
laurina R. Br. yielded the known alkaloid, liriodenine, and four new
substances. One of these, eupomatene, was shown by degradation to be
7-methoxy-3-methyl-2-(3?,4?- methylenedioxyphenyl)-5-trans-propenylbenzofuran.
The dihydro derivative and eupomatene itself were synthesized. It is proposed that
the term ?lignan? be extended to cover all natural products of low molecular
weight that arise primarily from the oxidative coupling of p- hydroxyphenylpropene
units and that eupomatene be then classified as a lignan. ��� A chlorotropolone has been isolated from a
Reimer-Tiemann reaction on a simple phenol.
Kinetics of the successive chlorination of 1,2-dichloroethane in the liquid phase
Authors: Caines DS , Paton RB , Williams DA , Wilkinson PR
Published: September 2010

Liquid 1,2-dichloroethane
has been chlorinated by dissolved chlorine to a succession of chloroethanes up
to the ultimate hexachloroethane. The results of both batch and continuous
stirred tank reactor systems have been analysed by computer techniques to give
a set of relative rate constants from which one can predict the product
composition for a given chlorine uptake, the aim in this work being to optimize
the production of tetrachloroethanes. An unusual feature of the kinetics is
that 1,1,1,2- and 1,1,2,2-tetrachloroethanes provide alternative pathways
between 1,1,2-trichloroethane and pentachloroethane.
Photochemistry of α-diketones. III. Some photochemical reactions of 1,1,4.4-Tetramethyl-2,3-dioxotetralin in carbon tetrachloride
Authors: Gream GE , Paice JC
Published: September 2010

Irradiation (at λ >
3000 Ǻ) of 1,1,4,4-tetramethyl-2,3-dioxotetralin (I) in carbon
tetrachloride under nitrogen gave 1,1,3,3- tetramethylindanone (III) (0.5%), 2-hydroxy-1,1,4,4-tetramethyl-3-
oxotetralin (II) (21%), 2-hydroxy-1,1,4,4-tetramethyl-3-oxo-2- trichloromethyltetralin
(IV) (14%), the cyclic unsaturated carbonate (VII) (7%), and
1-carboxymethyl-1,3,3-trimethylindanone (XII) (15%). When an atmosphere of
oxygen was used the products were very different: of the above-mentioned
compounds, only (III) (9%) was isolated. Other compounds isolated were
α,α?-o-phenylenediisobutyric anhydride (XIV) (16%), the peroxy acid
lactone (XIII) (5%), the lactone (XV) (16%), α,α?-o-phenylenediisobutyric
acid (XVI) (6%), and α-(o- isopropenyl)phenylisobutyric acid (XVII)
(trace). This composition closely paralleled that obtained when benzene was
used as solvent for the photooxidation.
Polyphenols in the leaves of Eucalyptus. Renantherin and macrantherin
Authors: Hillis WE , Morita H
Published: September 2010

The taxonomically important
polyphenol, renantherin, has the probable structure
4,6-dihydroxy-2-methoxy-1,3-xylene. A similar compound, macrantherin, has
properties consistent with a substituted phloroglucinol.
Acridone studies. V. The bromination of evoxanthine and norevoxanthine in methanol
Authors: Prager RH , Thredgold HM
Published: September 2010

Evoxanthine (1-methoxy-10-methyl-2,3-methylenedioxyacridone)
adds bro- mine and methanol to the 1- and 2-positions in preference to
substitution at the vacant 4-position. With norevoxanthine the o- complex
intermediate in the aromatic bromination has a sufficiently long lifetime to be
trapped as an addition compound. Reactions to prove the structures of the
compounds are described.
Paper electrophoresis of pyrrolizidine alkaloids
Authors: Frahn JL
Published: September 2010

The electrophoretic
mobilities of 27 pyrrolizidine alkaloids and related compounds are recorded for
seven electrolytes. In non- complexing electrolytes the compounds migrate as
cations, and electrophoresis at controlled pH affords useful separations of mixtures,
depending on differences in molecular weight and base strength of the
alkaloids. ��� In sodium borate and sodium arsenite,
compounds containing vicinal glycol groups also form anionic complexes to an
extent determined by their stereochemistry, and the cationic migration is
reduced or changed into anionic migration. Electrophoresis in complex-forming
electrolytes permits easy separation of some alkaloids which are
chromatographically indistinguishable, such as esters of trachelanthic and
viridifloric acids. Electrophoresis in borate is analytically useful for the
separation and determination of alkaloids of Heliotropium europaeum L. ��� Electrophoresis gave no evidence for
interaction between the alkaloids and copper, lead, or zinc ions in neutral or
slightly acidic solution. ��� Marked reduction of the cationic mobilities
of the alkaloids occurs in phosphate buffer at or near neutrality and is
probably caused by formation of ion-pairs from alkaloid cations and phosphate
ions. The mobilities of diesters of retronecine are most strongly depressed,
suggesting that a common structural feature in these alkaloids is especially
favourable for association with phosphate ions.
The diterpenes of Dacrydium kirkii
Authors: Cambie RC , Grant PK , Huntrakul C , Weston RJ
Published: September 2010

Examination of the
heartwood of Dacrydium kirkii has shown the presence of
isopimaradiene, sclarene, cis-biformene, trans-biformene, manoyl oxide,
14,15-bisnorlabd-8(17)-en-13-one, labda-8(17),13-dien-15-ol,
manool, isopimaradienol, β-sitosterol, torulosol, sandaracopimaradiene-
3β,19-diol, and isopimaric acid. Two new diterpene alcohols isolated have
been shown to be 7α-hydroxymanool (I) and 2β,3β-dihydroxymanoyl
oxide (II).
The weak field representation of the crystal field matrices of d4,6 ions and the electronic absorption spectrum of RbFeF3
Authors: Ferguson J , Guggenheim HJ , Krausz ER
Published: September 2010

The electronic absorption
spectrum of RbFeF3 is reported and
analysed by means of crystal field theory. It is shown that the strong field
formalism is limited for high spin Fe2+
and the weak field representation should be used to interpret the many triplet
states. Published spin-orbit weak field matrices for d4,6 are shown
to contain errors. The weak field matrices in the absence of spin-orbit
coupling have been derived and they are used to assign the spectrum of RbFeF3.
Galactomannan from the seed of Indigofera spicata
Authors: Ford CW
Published: September 2010

A galactomannan, isolated
in 3.2% yield from the seeds of Indigofera spicata (Leguminosae), has been
shown to consist of D-galactose and D- mannose in the ratio of 1 : 1.82. End
group determination by methylation showed 35.5%, in excellent agreement with the
result revealed by the periodate method. Partial acid hydrolysis, indicated
that the galactose was linked a to the 6-position of the mannose units. The
polysaccharide would appear to contain a linear backbone of (1→4)
β-D-manno-pyranose units with side-chains of α-D-galactopyranose
units attached to C6 of approximately five out of every nine D-mannopyranose
units.
Pepticle synthesis with the N-nitroso derivatives of sarcosine and proline
Authors: Stewart FHC
Published: September 2010

Various esters and salts of
N-nitrososarcosine and N-nitroso-L-proline have been prepared, and used to
provide amino and carboxyl components in model peptide syntheses. The sequential
polypeptide (Sar-Gly)n was synthesized
using the nitroso residue as an acid-sensitive protecting group. ��� Anomalous behaviour of some of the
N-nitroso derivatives in the Liebermann colour reaction is also discussed.
The preparation and magnetic properties of oxovanadium(IV) acetate
Authors: Casey AT , Thackeray JR
Published: September 2010

The variation of the
magnetic susceptibility of oxovanadium(IV) acetate with temperature may be
fitted to the Ising model of an infinite linear antiferromagnetic chain with
the exchange energy of -166 cm-1. On the basis of this and infrared
evidence a structure for the compound is proposed.
Preparation of 1,3-thiazines: Sulphur analogues of nucleic acid pyrimidine bases
Authors: Cain EN , Warrener RN
Published: September 2010

Sulphur analogues of uracil and thymine have been prepased, in which the N1 atom of the pyrimidine base has
been replaced by a sulphur atom. A number of general
synthetic methods are described for the synthesis of these 1,3-thiazines. The uracil analogues were prepared from the
related 2-thio-1,3-thiazines, by acid hydrolysis of
the 2-alkylthio derivative. 3,4-Dihydro-4-oxo-2-thio-2H-1,3-thiazine,
its N-methyl and N-ethyl derivatives were obtained by cyclization of the
addition compound resulting from the reaction of propiolic acid and the
appropriate dithiocarbamic acid. The generality of
this reaction, when propiolic acid is replaced with other acetylenic
acids or their related esters, is discussed. The crystalline addition compounds
obtained from dithiocarbamic acid and either
propiolic acid or methyl propiolate were all shown by
p.m.r, spectroscopy to have cis stereo-chemistry. The thymine analogues were prepared by an
alternative route, which utilized the intramolecular cyclization of S-ethyl-N-(β-methoxymethacryloyl)dithiocarbamate
to form 2-ethylthio-6-methyl-4-oxo-4H-1,3-thiazine,
followed by acid hydrolysis of the 2-ethylthio group.
Related intramolecular cyclization reactions of N-acyl-dithiocarbamates
formed the 5-acetyl-, the 5-cyano-6-methyl-, the 5-cyano-6-ethyl-, and the
6-methyl-2-ethylthio-1,3-thiazine derivatives. A
third approach involved the successful acid catalysed ring-opening-ring-
closure of a. 4-oxo-2-thio-1,3-oxazine to the
isomeric 2,4-dioxo-1,3-thiazine.
2- and 4-Methylcyclopent-2-enone and related compounds
Authors: Cavill GWK , Goodrich BS , Laing DG
Published: September 2010

2- and
4-Methylcyclopent-2-enone, and the ethylene acetal (16) of 3-formyl-4-methylcyclopent-2-enone have been synthesized.
Chemistry of the Podocarpaceae. XXIV. Ring-A modifications of Abieta- 8,11,13-trien-18-oic acid
Authors: Cambie RC , Franich RA
Published: September 2010

A convenient route from abieta-8,11,13-trien-18-oic acid (10) to abieta5,8,11,13-tetraen-3-one (27) has been developed involving selective
epoxidation of the alkene mixture (2) obtained by oxidative decarboxylation of
the acid with lead tetraacetate. Treatment of the 3a,4a-epoxide
(9) with lithium diethylamide gives a quantitative yield of the allylic alcohol (19). Brief treatment of this allylic alcohol with N-lithioethylenediamine
gives the α, β-unsaturated alcohol (25), which on oxidation affords
the enone (24). Methylation of the latter compound with methyl iodide and
potassium t-butoxide in t-butanol yields abieta-5,8,11,13-tetraen-3-one (27) in 43% overall yield
from the alkene mixture (2). Other reactions of the 3α,
4α-epoxide (9) are reported and discussed.
Antioestrogenic and antifertility compounds. II. Synthesis of optically active 2,3-Bis(p-methoxyphenyl)alk-1-enes
Authors: Collins DJ , Hobbs JJ
Published: September 2010

The enantiomers of
2,3-bis(p-methoxyphenyl)but-1-ene were synthesized by
different routes. The laevo
isomer, [α]D -73.6�, was derived by conversion of
(+)-erythro-2,3-bis(p-methoxyphenyl)butylamine into (+)-erythro-l-N,N-dimethyl- amino-2,3-bis(p-methoxyphenyl)butane, and
pyrolysis of the corresponding quaternary hydroxide. The absolute configuration
of 2,3-bis(p-methoxyphenyl)but-1-ene was established
as (+)-(R) by synthesis of the dextro isomer, [α]D + 72.50�, from (+)-(S)-2-(p-methoxyphenyl)propionic acid via (+)-(S)-3-(p-methoxyphenyl)butan-2-one. It follows that the absolute configuration of
(+)-eryihro-
2,3-bis(p-methoxyphenyl)butylamine is (2R,3S). (-)-2,3-Bis(p-methoxyphenyl)pent-1-ene, [α]D -49.5�, was synthesized from (+)-erythro-2,3-bis-(p-methoxyphenyl)pentylamine.
Chemical studies of the Proteaceae. IV. The structures of the major phenols of Grevillea striata; a group of novel cyclophanes
Authors: Ridley DD , Ritchie E , Taylor WC
Published: September 2010

Attempts to separate the
major constituents of the phenolic fraction of the ether extract of the wood of
Grevillea striata R.Br.
were unsuccessful, but by chemical degradation and spectroscopic methods the
structures of four of the components were deduced. They were mono- and di-methyl ethers of 17,19,22,24- tetrahydroxy(l4-p-0-o)cyclophane
with a double bond at either of two positions in the aliphatic chain. The new
ring system was given the trivial name "turriane".
Evidence that a fifth and a sixth component were derivatives with a saturated
chain, and a seventh was a derivative of a double homologue of turriane, was obtained. Synthetic experiments connected
with the structure determination, and on the synthesis of tetrahydroxyturriane
are described. Possible biogenetic routes to striatol
and the cyclophanes are discussed.
Pyrrolizidine- 1,2-epoxides. The α- and β-epoxides from monocrotaline
Authors: Culvenor CCJ , O'Donovan GM , Sawhney RS , Smith LW
Published: September 2010

Monocrotaline is not attacked at the l,2-double bond by the usual peraoid reagents but epoxidation is accomplished by trifluoroperacetic acid in excess tri-fluoroacetic
anhydride and chloroform. Under these conditions N-oxidation does not occur,
possibly because an acylammonium complex is formed.
Crystal field spectra of d3,7 ions. IV. The weak field representation of the spin-orbit matrices
Authors: Ferguson J
Published: September 2010

The spin-orbit crystal field matrices for d3,7 are given in the weak field repre-
sentation. They are used to assign the crystal absorption spectrum of CoSiF6,6H2O.
Electrical conductance of ionic liquids with water contents in the range 0-80 mole%
Authors: Angell CA
Published: September 2010

Measurements of electrical
conductance and density in a ternary alkali Nitrate + nitrite eutectic
system with water contents from 0 up to 82 mole % have been determined over a
temperature range determined by ebullition at the upper limit and crystallization
at the lower. The results, which are believed representative for salt-water
systems, have been interpreted according to equations containing the
"ideal glass" transition temperature as a key parameter, and the
dependence on water content of this and other
parameters in the equations has been assessed. The composition of the specific
conductance maximum has been interpreted in terms of characteristic behaviour
of the "ideal glass" transition temperature in aqueous solutions at
4-6N concentrations.
Interaction of heterocycles and nucleophiles. II. Sigma complexes formed from methoxide ion and Methoxy-3,5-dinitropyridines in dimethyl sulphoxide
Authors: Biffin MEC , Miller J , Moritz AG , Paul DB
Published: September 2010

Contrasting behaviour is
observed when 2- and 4-methoxy-3,5-dinitropyridine
interact with methoxide ion in dimethyl sulphoxide.
The 4-methoxy compound affords both methine and
acetal sigma complexes, the latter being thermodynamically more stable. The interconversion is catalysed by methanol. Labelling
experiments have established that the sigma complex from the 2-methoxypyridine is formed by addition at C6; no conversion
into the acetal could be effected. These observations are rationalized in terms
of differential steric and solvation effects. Demethylation and
rearrangement reactions of 4-methoxy-3,5-dinitropyridine
are reported.
Electronic absorption spectra for copper(II) polyamine complexes
Authors: Hedwig GR , Love JL , Powell HKJ
Published: September 2010

The preparations and
visible and ultraviolet absorption spectra are reported for a series of copper(11) complexes with linear and cyclic
aliphatic ligands which each have four nitrogen donor atoms. Data are compared
with that for 16 analogous complexes. For linear polyamines of
different chain length the ligand field strength, as denoted by vmax (visible), is found to increase with
increasing thermodynamic stability of the
copper(11) complex in aqueous solution. For linear and cyclic ligands
the ligand field strength is a maximum for
complexes containing a combination of five- and six-membered chelate rings.
The preparation of isomeric 1-substituted 4-t-Butyl-1-methylcyclohexanes
Authors: Beeby PJ , Sternhell S
Published: September 2010

Seventeen title compounds
were synthesized and their configurations were determined by relating them to
compounds of known stereochemistry.
Derivatives of 1,10-Phenanthroline-5,6-quinone
Authors: Dickeson JE , Summers LA
Published: September 2010

1,l0-Phenanthroline-5,6-quinone
is prepared from 1,l0-phenanthroline via 5-nitro-1,l0-phenanthroline and
5-amino-1,l0-phenanthroline. It is converted by standard methods into 4,5-diazafluoren-9-one, 4,5-diazafluoren-9-ol,4,5-diazafluorene,
and the new heterocyclic system dipyrido[3,2-a:2',3'-clphenazine. These four compounds each form a complex with
cupric chloride. They thus represent a new series of chelating agents. By
reaction with ethylene dibromide, dipyrido[3,2-a:2',3'-c]-phenaiine forms a diquaternary
salt which is reduced in aqueous solution by a one-electron transfer to a
highly coloured radical cation. Polarography
experiments show that the reduction potential of the salt is -0.40 V against a
standard calomel electrode.
Nitrogenous chelate complexes of transition metals. VII. Complexes of silver(I) and silver(II) with tridentate chelating ligands
Authors: Harris CM , Lockyer TN
Published: September 2010

Silver(1) complexes of
2,2',2"-terpyridine and a related Schiff base
chelate 8-(or-pyridylmethyleneamino)quinoline have been prepared. They are of the type Ag(chelate)X,
where X = NO3, ClO4, and PF6.
Both Ag(terpy)+ and Ag(pmq)+
are stable in solution and conductance measurements have been obtained. Ag(terpy)PF6
is monomeric in nitrobenzene. Reaction of the above complex ions with pyridine
or triphenylphosphine affords stable species of the form [Ag(chelate)(py)]+
and [Ag(chelate)(Ph3P)]+ which
have been isolated as their perchlorate salts. Both Ag(chelate)+ and
[Ag(ohelate)L]+ involve unusual
stereochemistry for AgI. The known paramagnetic AgII complexes Ag(terpy)X2
(X = NO3, ClO4, �S2O8)
have been reprepared. They are unstable in solution and reduce readily
to AgI. They all show magnetic moments in the range
1.7-1.9 B.M. Ag(terpy)2+ in an aqueous
solution of CeIv shows a strong absorption
band at 470 mμ (880).
Some reactions of nitrogen bases with cobalt(II) complexes of the bidentate chelate Di(2-pyridyl) sulphide
Authors: Bridson ME , Walker WR
Published: September 2010

Cobalt(11) compounds
containing the chelate di(2-pyridyl)
sulphide (dps) of the types Co(dps)X2
(X = Cl, Br, and I) and Co(dps)2X2
(X = Cl, Br, and NCS) have been prepared and investigated. An attempt to
prepare cobalt(11) complexes containing mixed chelates such as Co(dps)(4-mepy)2X2
(4-mepy = 4-methylpyridine)
was unsuccessful. However, a spectrophotometric investigation of the following
replacement reactions

Co(dps)Cl2
+ 2(N-base) ↔ Co (N-base)2Cl2
+ dps

was carried out in
chloroform and room-temperature equilibrium constants were determined. For
N-base = 4-mepy, pyridine, 4-ethylpyridine,
isoquinoline, 4-benzoylpyridine,
quinoline, and 4-cyanopyridine
K values were evaluated as 113, 73, 56, 43, 10, 0.7, and 0.03 respectively. For the
tetrahedral-octahedral configurational equilibrium

Co(4-mepy)2X2 + 2(4-mepy) ↔ Co(4-mepy)4X2(X = Cl, Br, and I)
equilibrium constants have been determined at room temperature in chloroform as
13.2, 12.9, and 8.7 respectively.
The oxidation of thioureas and related compounds in the presence of pyrroles. The synthesis of S-pyrrolylisothiouronium salts
Authors: Harris RLN
Published: September 2010

The oxidation of thioureas
in the presence of pyrroles by halogens or hydrogen
peroxide in acidic conditions gives S-pyrrolylisothiouronium salts in high yield. The mechanism
of the reaction is believed to involve oxidation of the thiourea to a sulphenyl halide species which then reacts with the pyrrole in a typical electrophilic substitution. The
reaction has been extended to include several thioamides
and heterocyclic thiols as well
as thiourea.
Compensation effect in mixtures of organic semiconductors
Authors: Ulbert K
Published: September 2010

Results obtained with
mechanical mixtures of two chemically stable and non-interacting organic
semiconductors confirm the validity of the compensation effect. For the specific
conductivity value and its activation energy in mixtures the generalized Lichtenecker's "logarithmic mixing rule" applies;
from this immediately follows the existence of compensation effect. This
general phenomenon may in some cases be responsible for the existence of
compensation effect described in the literature.
Cobalt(II) gluconate complexes
Authors: Ashton JF , Pickering WF
Published: September 2010

A study of the cobalt(11) gluconate system has confirmed the existence of an unstable
cationic species [Co(C6H1107)]+, in
solutions of pH <7.5, and two insoluble compounds, CO2(OH)3(C6H11O7),xH2O and CO3(C6H10O7)2(OH)2,2H2O,
formed in solutions of pH 7.5-9.5. Above pH 9.5 an anionic species, which is
subject to rapid auto-oxidation, exists in solution.
Electron impact studies. LVI. The fluorenyl and phenalenyl cations. The application of metastable characteristics
Authors: Bowie JH , Bradshaw TK
Published: September 2010

A study of the abundances
of certain metastable peaks formed by the de- composition of ions in the
first and second field-free regions of a double-focusing mass spectrometer has
shown that the M-1 ions (m/e 165) in the mass spectra of fluorene
and phenalene have different structures. Correlations
based on these structures have been obtained for C13H9+
species formed from different systems.
Transition metal complexes of substituted alkynes. VII. Some cyclopentadienone complexes of cobalt and rhodium
Authors: Dickson RS , Tailby GR
Published: September 2010

π-Cyclopentadienone-π-cyclopentadienyloobalt complexes have been prepared from
reactions of π-oyclopentadienyldicarbonylcobalt
and the alkynes bis(pentafluorophenyl)acetylene and
2,3,4,5,6-pentafluorodiphenylacetylene. Spectroscopic
data indicate that the complex derived from the latter alkyne has an
unsymmetrical arrangement of the substituents in the cyclopentadienone ring. It
is formulated as 2,4-bis(pentafluorophenyl)-3,5-diphenylcyclopentadienone-π-cyclopentadienyl-cobalt. A related cyclopentadienone
complex, π-tetrakis(pentafluorophenyl)cyclopenta-dienone-π-cyclopentadienylrhodium has been
prepared from π-cyclopentadienyl-dicarbonylrhodium
and bis(pentafluorophenyl)acetylene. Similar organorhodium complexes could not be isolated from
reactions of π-C5H5Rh(CO)2
with diphenylacetylene and 2,3,4,5,6-pentafluorodiphenylacetylene. These compounds could, however, be prepared
indirectly by the in situ treatment
with thallous cyclopentadienide of the
cyclopentadienone complexes formed in reactions of [Rh(CO)2Cl]2 with RC=CR' (R = phenyl, R' =
phenyl or pentafluorophenyl). Like its cobalt
analogue, π-bis(pentafluorophenyl)diphenylcyclopentadienone-.π-cyclopentadienyl- rhodium has an
unsymmetrical arrangement of the substituents in the ring.
Triterpenes of the friedelane series. VII. The structure of Friedelan-x-one
Authors: Clarke BJ , Courtney JL , Stern W.
Published: September 2010

The photolysis of 3β-hydroxyfriedelan-α-one results in the loss of
acetaldehyde from ring E and the formation of a non-conjugated diene. The
structure of this diene is established and its formation allows the location of
the α-oxo group to be assigned to C21.
Advantages and limitations of the grooved Wilhelmy plate
Authors: Princen HM
Published: September 2010

A detailed analysis has
been made of the grooved Wilhelmy plate as an instrument for measuring
surface and interfacial tensions. It is shown, on the assumption of V-shaped
vertical grooves, that the method can lead to errors if the weight of the dry
plate is used as the reference force. In practical cases the error can be of
the order of 1%. Quantitative expressions are given for the correction factor
to be employed. It is also shown that no correction factor is required, providing
one takes as the reference force the weight of the plate after it has come to
equilibrium with the vapour phase, and capillary condensation of vapour in the
grooves has taken place. This equilibrium will not readily be realized in
practice, and an alternative procedure is proposed which utilizes the weight of
the plate after it is detached from the liquid. The conclusions may also apply,
at least semi-quantitatively, to randomly roughened, rather than regularly
grooved, plates.
A non-stereospecific synthesis of (±)-davanone
Authors: Birch AJ , Corrie JET , Subba Rao GSR
Published: September 2010

A synthesis of the
optically inactive form of the natural sesquiterpene

davanone (1)together with three stereoisomers has been
carried out as in Scheme. Although not
subject to steric control, the synthesis confirms the structure of davanone, and leads to the suggestion that the relative
stereochemistry may be that shown in (16). The preparation and some reactions
with carboxylic acids of 3-methylbut-2-enyllithium
are described.
A ruthenium chloro nitrosyl derivative of dithioacetylacetone
Authors: Heath GA , Martin RL
Published: September 2010

The novel dithioacetylacetonato complex [Ru(C5H7S2)2(NO)Cl] has been characterized by analytical and spectral methods. A trans configuration is suggested. The electronic spectrum is consistent with the oxidation state II for the coordinated metal ion.
Quantitative studies of the role of alkenes during the combustion of alkanes
Authors: Berry T , Cullis CF
Published: September 2010

Studies of the combustion of n-butane in the presence of small amounts of [1-14C]but-1-ene and [2-14C]but-2-ene have enabled the role and importance of the two alkenes in the oxidation of the alkane to be determined quantitatively. Thus at 315�, at a stage when the reaction rate has started to decline, over one-third of the n-butane which has reacted has been oxidized to butenes and nearly two-thirds of these two alkenes has reacted further to give other products. All the larger-ring oxa-heterocyclic products and the major part of the oxirans arise by a mechanism not involving the intermediate formation of C4 alkenes but a substantial proportion of the 2-ethyloxiran and 2,3-dimethyloxiran are formed by the direct oxidation of but-1-ene and but-2-ene respectively. About one-quarter of the C4 ketones and an appreciable part of the lower molecular weight aldehydes also appear to be formed by an alkenic route. The general conclusion which emerges is that at the temperature concerned butenes play an important but not overwhelming role as intermediates in the combustion of n-butane.
The chemistry of pyrrolic compounds. XIII. Electronegatively substituted oxyporphyrins
Authors: Clezy PS , Liepa AJ
Published: September 2010

The synthesis of a range of electronegatively substituted oxyporphyrins is described and their spectroscopic properties discussed. Selected members have been converted into the corresponding porphyrin by treatment of the enol acetate derivative of the oxyporphyrin with hydrogen over a palladium catalyst.
Chemistry of the Podocarpaceae. XXVI. Ring-c modification of 12-Hydroxypodocarpa-8,11,13-trien-19-oic acid
Authors: Cambie RC , Denny WA , Klose TR , Mander LN
Published: September 2010

Methods for the conversion
of 12-hydroxypodocarpa-8,11,13-trien-19-oic acid (1)
into the α,β-unsaturated ketones (6) and
(7) have been investigated. Lithium in liquid ammonia reduction of the ester
(19) and the hydroxy acid (24) with concomitant decarboxylation gives moderate
yields of the desired products. The ketone (7) has also been prepared in
improved yield by a modification of Bible and Burtner's
method involving the intermediates (9), (35), (12), (16), (17), and (18).
Fluorocarbon-aluminium compounds. II. Reactions of hexafluorobenzene, pentafluorobenzene, and 1,2,4,5-tetrafluorobenzene with lithium tetrahydroaluminate
Authors: Dickson RS , Sutcliffe GD
Published: September 2010

Reaction of lithium
tetrahydroaluminate with hexafluorobenzene yields pentafluorobenzene.
Pentafluorobenzene reacts further with LiAlH4
to give 1,2,4,5-tetrafluorobenzene. The products are formed by a combination of
(i) reduction (hydride for fluoride replacement) of
the fluoroaromatic compound, and (ii) hydrolysis of one of the compounds LiAl(C6F4H)H2F or LiAl(C6F5)H2F that are
formed in the reactions. These competing reactions take place to a similar
extent and are much faster in tetrahydrofuran than in diethyl ether. ��� In tetrahydrofuran, 1,2,4,5-tetrafluorobenzene
is metalated by LiAlH4. The compounds LiAl(C6F4H)H3, LiAl(C6F4H)2H2,
and LiAl(C6F4H)3H
are proposed as products of the reaction. ��� The fluorocarbon-aluminium compounds have
been characterized by quantitative determination of the products of hydrolysis
and by 1H and 19F N.M.R. spectroscopy.
Palladium(II) and platinum(II) complexes of 2,9-Dimethyl-1,10-phenanthroline. II. Effects of steric overcrowding on coordinated polyatomic anions
Authors: Plowman RA , Power LF
Published: September 2010

Complexes of
2,9-dimethyl-1,10-phenanthroline with palladium(II) and platinum(II) with
polyatomic anions are described. The effect of steric overcrowding on the
molecular geometry is discussed on the basis of spectral evidence.
Aromatic amides. VI. Proton magnetic resonance spectra of some 2-substituted 1,3-phenylenediamines and their N,N'-diacyl derivatives
Authors: Andrews BD , Rae ID
Published: September 2010

A number of 2-substituted
1,3-phenylenediamines and their N-acyl and N,N?-diacyl derivatives have been
prepared and the proton magnetic resonance spectra examined for evidence that
hydrogen bonding between the amide protons and the 2-substituents can occur so
as to constrain two amido groups to coplanarity with the aromatic ring. The
nitro and methylsulphonyl substituents behave in this way. Weaker, but still
effective, dual hydrogen bonding to methoxycarbonyl, chloro, methoxy, and
methylthio substituents is observed. A new technique is described for
performing the Hoffman degradation of the bis-amide of 2- nitroisophthalic acid
to 1,3-diamino-2-nitrobenzene.
The gas-phase reaction of acetic acid with hydrogen bromide. The effect of isobutene
Authors: Daly NJ , Gilligan MF
Published: September 2010

Addition of isobutene to
reaction mixtures of acetic acid and hydrogen bromide brings about a lowering
in the initial rate of pressure change. The lowering is proportional to the
pressure of isobutene and is explained in terms of a molecular reaction producing
mesityl oxide. Mesityl oxide is formed steadily throughout the course of the
reaction in quantities proportional to the pressure of isobutene. The
quantities of mesityl oxide detected are less than those required to account
quantitatively for the lowering of dp/dt, but the
presence of the products of the thermal reactions of mesityl oxide, and the
minima observed in the pressure-time curves at 407� show that the discrepancies
can be accounted for in terms of the polymerization undergone by mesityl oxide
in the presence of hydrogen bromide. The reaction appears analogous to the
formation of mesityl oxide by the acetylation of isobutene in solution.
Thermal decomposition of citraconic anhydride
Authors: Daly NJ , Ziolkowski F
Published: September 2010

Citraconic anhydride
decomposes in the gas phase over the range 440- 490� to give carbon dioxide,
carbon monoxide, and propyne which undergoes some polymerization to
trimethylbenzenes. The decomposition obeys first-order kinetics, and the
Arrhenius equation

������������������� k1 = 1015.64
exp(-64233�500/RT) (s-1)

describes the variation of
rate constant with temperature. The rate constant is unaffected by the addition
of isobutene or by increase in the surface/volume ratio of the reaction vessel.
The reaction appears to be unimolecular and if a diradical intermediate is
involved it may not be fully formed in the transition state.
Stereochemical studies. II. Synthesis and deamination of cis-2-Amino-cis-4-t-butyl-1-methylcyclohexanol
Authors: Lewis PH , Middleton S , Rosser MJ
Published: September 2010

The title compound (15) has
been synthesized unambiguously from 4-t- butyl-1-methylcyclohexene (11). When
treated with nitrous acid, it undergoes ?normal? stereospecific deamination to
give the ring- contracted product (17) in contrast to the known ?abnormal?
behaviour of the related amino sterol (7).
Phenylnaphthalene pigments of Lachnanthes tinctoria. II. Synthesis of two phenylnaphthalides
Authors: Cooke RG , Fletcher RAH
Published: September 2010

The structures previously
assigned to two of the fully methylated lactones derived from Lachnanthes
tinctoria constituents have now been confirmed by synthesis. Nuclear magnetic
resonance spectra have been used for a study of the stereochemistry of highly substituted
phenyltetralins obtained as intermediates in the syntheses.
The chemistry of pyrrolic compounds. XV. Porphyrins from electronegatively substituted bilenes and biladienes
Authors: Clezy PS , Liepa AJ
Published: September 2010

The preparation is reported
of a number of 1,19-dimethyl-1,19-dideoxybilenes-b and 1,19-dimethyl-1,19-dideoxybiladienes-ac
which carry electronegative substituents. These linear tetrapyrroles can be
cyclized to porphyrins in good yield by means of copper acetate in pyridine
solution.
Composition and preliminary fractionation of the seed mucilage of Ocimum canum
Authors: Anjaneyalu YV , Tharanathan RN
Published: September 2010

The capsular mucilage of
the seeds has been extracted in 7% yield. It is partly O-acetylated (OAc, 4.0%) and contains lipids (?free? 24% and ?bound? 5%).
The mucilage is composed of D-glucose, D-galactose, D- mannose, L-arabinose,
D-xylose, and L-rhamnose in the approximate ratio 8 : 5 : 2 : 1 : 1 : 2 and
uronic acids (8.15%). The uronic acids were identified as D-galacturonic and D-mannuronic
acids. The mucilage was fractionated into an acid-soluble fraction, which was
significantly acetylated (OAc, 6.6%) and rich in
uronic acids (34.4%) and pentosans, and an acid- insoluble fraction rich in
hexosans. The latter on further fractionation with alkali gave a glucomannan
with glucose and mannose in the ratio 10 : 3, end a galacto-glucomannan with
galactose, glucose, and mannose in the ratio 2 : 4 : 1. Thus the mucilage is
heterogeneous, containing at least three different polysaccharides, and is
comparable to cellulose-containing seed mucilages and acidic bacterial
polysaccharides.
The electronic spectra and magnetic behaviour of some dithiocacodylate complexes
Authors: Casey AT , Mackey DJ , Martin RL
Published: September 2010

The large nephelauxetic
effect and low ligand field strength produced by the dithiocacodylate group
[(CH3)2AsS2-] in complexes with Ni2+,
Co2+, and Cr3+ is explained in terms of significant
covalency of the metal- sulphur bonds. The Mn2+ compound, however,
has properties consistent with considerable ionic character. ��� The electronic spectrum and magnetic behaviour
of bisdithiocacodylato-cobalt(II) can be better interpreted in terms of
tetrahedral rather than octahedral CoSx microsymmetry. On the other hand, the
Ni2+ compound is square-planar and both the Mn2+ and Cr3+
compounds appear to be octahedrally coordinated by sulphur atoms.
Reactions of epoxides. XXVII. The boron trifluoride catalysed rearrangement of 11α, 12α-Epoxy-12β-phenyltigogenin
Authors: Ames LJ , Baines AFH , Coxon JM , Hartshorn MP
Published: September 2010

The boron trifluoride catalysed
rearrangement of the 12β-phenyl- 11α,12α-epoxide (1c) gives the
rearranged diene (9), hydroxy olefin (10), and the c-seco aldehyde (12).
Ring strain and the negative pole. V. The interaction of a strained system with non-directly bonded charge
Authors: Miller IJ
Published: September 2010

The electrostatic
interaction of small rings with charge is used to explain the reactivity of
several compounds involved in solvolyses, and in particular exo and endo fused
rings of 7-syn and 7-anti substituted norbornanes.
Provided that the interaction between the ring and the leaving group is
accounted for, the calculated results are in good accord with experiment. In
particular, the effect of a cyclopropyl or vinyl group forced into the ?crown? conformation
on an adamantyl carbonium ion is accountable. The ease of protonation of a
strained system is discussed, and the edge protonation of bicyclobutane is
calculated to be faster than bridgehead protonation. Tetrahedrane is predicted
to be protonated by any trace of water. Boranes are compared with protonated
hydrocarbons and the structures of some simple boranes are rationalized. The
existence of a new stable isomer of B4H10 is predicted.
The infrared and proton magnetic resonance spectra of hydroxyl ion and water in a potassium nitrate-sodium nitrite melt
Authors: Turnbull AG
Published: September 2010

The infrared and proton
magnetic resonance spectra are reported for OH- and H2O at low
concentration (<2 mol %) in a KNO3-NaNO2 melt at
150�C. The spectra indicate the absence of hydrogen bonding and the presence of
restricted rotation and translation for OH- but the presence of strong
complexing to cations and anions for H2O.
Chemistry of the Podocarpaceae. XXXV. 12-Methoxypodocarpa-8,11,13- triene and 12-Methoxyabieta-8,11,13-triene derivatives: A synthesis of (+)-hinokione methyl ether
Authors: Cambie RC , Fullerton TJ
Published: September 2010

12-Methoxypodocarpa-8,11,13-trien-19-oic
acid (9) and 12-methoxyabieta- 8,11,13-trien-19-oic acid (10) have been converted into
3-0x0-4,4-dimethyl derivatives (15) and (18) by successive reactions involving
oxidative decarboxylation, selective epoxidation, epoxide opening, double bond
isomerization, oxidation, and reductive methylation. The sequence starting from
the acid (10) provides a synthesis of the methyl ether of hinokione (14).
The inclusion of electron correlation in calculations on large molecules
Authors: Peacock TE
Published: September 2010

This paper reviews some of
the methods by which electron correlation can be included in calculations on
large conjugated molecules. The methods discussed are applied to benzene and
the linear polyenes.
Activity coefficient assumptions in the determination of association constants. VII. Explicit assumptions in the analysis of solubility and absorbance measurements on thallium(I) chloride and bromide
Authors: Chan CY , Panckhurst MH
Published: September 2010

In an attempt to resolve
discrepancies between association constants obtained from solubility and
absorbance measurements for thallium(1) chloride and bromide the explicit
assumptions used in the various analyses have been considered in detail. It is shown that the discrepancies can be
accounted for in part by considering the activity coefficient of the complex TlCl or TIBr, and, more
importantly, by allowing for the presence of small amounts of higher complexes
in analysing absorbance data. It is also shown, in
determining association constants using a specific ionic activity coefficient
expression, that uncertainties in some interaction coefficients reduce the
usefulness of our solubility measurements in non-common ion salts. In
particular, it is concluded, using the specific ionic interaction coefficient
expression, that association constants can at present only be arrived at from
solubility measurements by specifying arbitrary interaction coefficients for
thallium(1) and halide ions; and to obtain association constants using a
non-specific ionic activity coefficient expression it is necessary to assume
unnecessarily arbitrary subsidiary association reactions as well as an arbitrary value
for the activity coefficient parameter B.
The electronic spectrum of KCoF3: Exchange effects
Authors: Ferguson J , Wood TE , Guggenheim HJ
Published: September 2010

An analysis of the
absorption spectrum of KcoF3 based on the weak field spin-orbit matrices has led
to an assignment of all the doublet states of the d7 configuration
using the parameters Dq = 780 cm-l, F2
= 1440cm-l, F4 = 104.5 cm-l and the spin-orbit
coupling constant 5 = 490 cm-l. F2 F4, and
< correspond to 91%, 94%, and 91% of their respective free ion values. The spectral absorption intensities of the
spin forbidden transitions between 26000 and 40000 cm-l are much too
large to be accounted for by the conventional spin-orbit coupling mechanism and
one involving exchange interactions between pairs of ions is indicated.
Consistent with this mechanism 1s the appearance of nine absorption regions
which correspond to the simultaneous electronic excitation of pairs of ions.