bluuebunny/crossref_metadata_2025 huggingface dataset:
Rates of formation of isoperthiocyanic acid (5-Amino-1,2,4-dithiazole-3-thione) from thiocyanate in aqueous solution
Authors: Hall WH , Wilson IR
Published: September 2010

The rates of formation of
5-amino-1,2,4-dithiazole-3-thione from potassium thiocyanate in aqueous
sulphuric acid have been studied spectrophotometrically. They show close to
third-order dependence on thiocyanate concentration and linear dependence on
the Hammett acidity function, h-. Between 25 and 45� the rate
constant is given by the Arrhenius expression

k = 9.27 x 10-5exp(-8800/T)
1.2 mole-2 sec-1

A mechanism is proposed.
The effect of heterogeneity in composition on the determination of molecular weight distribution of block copolymers by gel permeation chromatography
Authors: Urwin JR , Cramond DN
Published: September 2010

The molecular weight of
samples of block copolymers of poly(isoprene : styrene) determined by gel
permeation chromatography (g.p.c.) are found to
deviate from the values obtained by light scattering and osmometry. The extent
of the deviation depends on composition, and comparision of (g.p.c.) values with osmometry (MN) can be
interpreted if account is taken of the effect of heterogeneity. The drift in
composition with molecular weight calculated from light scattering data can be
used to predict the direction of the deviation, at least qualitatively.
Structure and reactivity of the arenecarbonyl cation iodotricarbonylhexamethylbenzenetungsten(II)
Authors: Snow MR , Pauling P , Stiddard MHB
Published: September 2010

Substituted carbonyls of
the type (arene)M(CO)3 (M = Mo, W) react with iodine to yield
compounds containing the cation [(arene)M(CO)3I]+. X-ray
structure analysis shows the [(hexamethylbenzene)W(CO)3I]+
species to possess approximate Cs symmetry. It is unstable in
solution and reaction with bipyridyl and triphenyl-phosphine offers a new route
to derivatives of the type W(bipyridyl)2(CO)3I2
and W(PPh3)2(CO)3I2.
Studies related to naturally occurring acetylene compounds. XXXV. Investigation of Erigeron spp. from the Australian mountains and Tasmania
Authors: Sorensen JS , Sorensen NA
Published: September 2010

Two Australian members of
the genus Erigeron L. (Compositae, tribe Astereae) have been investigated with particular regard to
their content of acetylenic compounds. E. conyzoides
F. Muell. contained the methyl esters (I) and (II) of
acetylenic carboxylic acids and their corresponding lactones (III) and (IV) and
in this resemble the numerous Erigeron spp. of the
northern hemisphere investigated earlier. Of the collective species E. pappochroma Labill. three
Tasmanian and two Snowy Mountain collections were investigated. None of them
contained the acetylenic compounds characteristic of typical Erigeron. Three of
these collections contained some simple acetylenic alcohols, (V)-(IX); some of
these are characteristic compounds of other genera of the tribus Astereae. In two collections acetylenic compounds were
seemingly absent; but dill apiol (XI) was found in
appreciable amounts.
Nuclear magnetic resonance spectroscopy of denatured proteins
Authors: Bradbury JH , King NLR
Published: September 2010

The proton magnetic
resonance spectroscopy of 11 proteins (molecular weight range 5700-650000) has
been investigated in five denaturing solvents, viz., trifluoroacetic acid-d,
formic acid, dichloroacetic acid, 6M guanidine hydrochloride in D2O,
and 8M urea in D2O. The chemical shifts, line-widths, and
intensities of the resonances have been measured of the histidine C2 protons,
the methionine SCH3 protons and methyl protons of leucine,
isoleucine, and valine, the aromatic protons, and the α-CH protons. ��� It is found that, with some exceptions
delineated below, the line- widths of the methyl resonances are constant for a
particular solvent, independent of the molecular weight of the protein. This
indicates that, in general, the proteins behave as random coil structures in
these solvents, which confirms the conclusion reached by Tanford
and co-workers1-4 for 6M
guanidine hydrochloride. ��� However, methyl line broadening occurs in
dichloroacetic acid for catalase and fibrinogen, in guanidine hydrochloride for
insulin, and in urea for insulin and lysozyme. Furthermore, the C 2 histidine
resonance is absent in dichloroacetic acid solutions of thyroglobulin, catalase,
and fibrinogen; the SCH3 resonance is absent in myoglobin in trifluoroacetic
acid-d and occurs as a doublet for trypsin in guanidine hydrochloride and in
urea. A general line broadening of resonances indicates association and/or incomplete
unfolding of molecules, whereas perturbations of only one particular resonance,
as in the cases detailed above, are probably due to intramolecular non-covalent
interactions which involve the perturbed group and another unspecified group in
the protein. ��
Trimethylaluminium: Scrambling of methyl groups in the dimer and exchange with trimethylgallium
Authors: Jeffery EA , Mole T
Published: September 2010

Interchange of methyl
groups between the bridging and terminal positions of trimethylaluminium dimer
and exchange of methyl groups between trimethyl- aluminium and trimethylgallium
in cyclopentane have been re-examined, again by means of proton magnetic resonance
spectroscopy. Dissociation of the dimer is confirmed as the rate- determining
step in both cases, but the rate of dissociation is much greater in toluene
than in cyclopentane. The evidence previously put forward for a cage effect
limiting the rate of exchange with trimethylgallium in cyclopentane is refuted
and a revised mechanism for exchange is suggested.
Photochemical syntheses. I. The formation of the naphthalene-diphenylacetylene photo-adduct
Authors: Sasse WHF
Published: September 2010

The yield of the adduct in
the light-induced naphthalene- diphenylacetylene addition depends inter alia on the concentrations of naphthalene and diphenyl-acetylene,
and their ratio, the wavelengths of the incident light, and on the temperature
of the reaction. The addition is retarded by oxygen and can be completely
inhibited by benzophenone. A mechanism for the addition is discussed which
involves the rearrangement of an exciplex derived from diphenylacetylene and
singlet naphthalene.
The vibrational spectra of 4-pyridone, and its 2,3,5,6-tetradeutero, N-deutero, N-methyl, N-cyano, and 3,5-dihalogeno derivatives. Mixing between C=C and C=O stretching vibrations
Authors: Batts BD , Spinner E
Published: September 2010

The infrared spectra of the
above compounds, and the Raman spectra of the parent compound and its 2,3,5,6-D4,
1-D, and 1-Me derivatives have been determined. The effects of
electron-withdrawing substituents, N- methylation, and deuteration on the two
intense infrared bands in the 1480-1650 cm-1 region are not
compatible with one being a C=O and the other a C=C stretching band. These two
vibrations must be extensively mixed; occasionally very pronounced medium
effects, which are not straightforward, are observed for one or both of these
bands. The spectra are not in accord with a mostly zwitterionic (N-protonated
pyrid-4-oxide) structure (II) of 4-pyridone. Band assignments are made for the
parent compound.
Reductive acetylation of an aurone: Formation of a dimeric product
Authors: Clark-Lewis JW , Jemison RW
Published: September 2010

Reductive acetylation of 4,6,3',4'-tetramethoxyaurone
gave a dimer, considered from spectroscopic evidence to be 1,2-di(3-acetoxy-4,6-dimethoxybenzofuran-2-yl)-
1,2-di(3,4-dimethoxypheny1)ethane.
Carbonyl halides of the Group VI transition metals. XVIII. Bis(diphenylphosphino)methane derivatives of iodocarbonyls of molybdenum
Authors: Colton R , Howard JJ
Published: September 2010

Bis(diphenylphosphino)methane,
dpm, reacts with hexacarbonylmolybdenum
to give Mo(CO)4 dpm and subsequently trans-Mo(CO)2(dpm)2. Oxidation of the tetracarbonyl
derivative with iodine yielded Mo(CO)3(dpm)I2;
reaction of this complex with further dpm gave Mo(CO)2(dpm)2I2. As with the corresponding
tungsten system there are two isomers of Mo(CO)2(dpm)2I2
and three isomeric forms of Mo(CO)2(dpm)2I2
which can be obtained by this method of synthesis, all of which have been
isolated and characterized individually.

trans- Mo(CO)2(dpm)2 reacts with iodine to give a fourth
isomeric form of the iododicarbonyl complex, trans- [Mo(CO)2(dpm)2]I2 which is a new type of
halocarbonyl complex of molybdenum(11).
Transition metal complexes of substituted alkynes. V. Compounds derived from Tri- and Tetra-cobalt carbonyl complexes
Authors: Dickson RS , Tailby GR
Published: September 2010

Treatment of dodecacarbonyltetracobalt with several fluorocarbon alkynes
has given complexes of stoicheiometry Co4(CO)10,(alkyne). For comparison,
analogous complexes of the related hydrocarbon alkynes have also been prepared.
Infrared, nuclear magnetic resonance, and mass spectra of the complexes are
given and the probable structure of the complexes deduced. The reaction of both
fluorocarbon and hydrocarbon alkynes with the cluster carbonyl compounds Co3(CO)9CY (Y = CH3, C6H5,
CO2CH3) has also been investigated. The products obtained
in these reactions include substituted benzenes and the two organocobalt
complexes Co2(CO)6(alkyne) and Co2(CO)4(alkyne)3. The
probable mode of formation of these compounds is discussed. The role played by the
various complex types in the reactions of alkynes with cobalt carbonyls is also
considered.
Natural pungent compounds. III. The paradols and associated compounds
Authors: Connell DW
Published: September 2010

A new series of pungent
compounds, the 1-(4'-hydroxy-3'-methoxyphenyl).

alkan-3-ones, has been isolated from grains of paradise (Amomum melegueta Roscoe) and detected
in ginger (Zingiber officinale
Roscoe). The name, paradol, which has been previously applied to a mixture of
these compounds and the gingerols, is suggested as a
group name prefixed with a number corresponding to that given to the gingerol with the same side-chain length to distinguish
individual members. The structure of [6]-paradol, as suggested by spectroscopic
techniques, was confirmed by synthesis from [6]-gingerol.
It occurred in grains of paradise in quantities up to 1.5% and was accompanied
by (+)-[6]- gingerol in almost equal amounts. Trace
quantities of [8]-gingerol, [a]-paradol, and [6]-shogaol were also present.
The chemistry of pyrrolic compounds. IX. The synthesis of 5,5'-diformyldipyrrylketones and their derivatives
Authors: Clezy PS , Liepa AJ , Nichol AW , Smythe GA
Published: September 2010

Treatment of 5,5'-diformyldipyrrylmethanes with bromine followed by

sulphuryl chloride yields 5,5'-diformyldipyrrylketones.
Also, this type of product, or the acetoxymethyl
derivative, can be obtained in certain cases by the lead tetraacetate oxidation
of 5,5'-dimethyldipyrrylketones.
Nitrogenous chelate complexes of transition metals. VI. Complexes of copper(II) with 2,2',2'-terpyridine
Authors: Harris CM , Lockyer TN
Published: September 2010

A series of compounds of
the general type Cu(terpy)X2 (terpy = 2,2',2"-

terpyridine; X = Cl, Br, I, NCS) have been prepared. The above
complexes are sparingly soluble in non-aqueous media in which they show some
ionization to yield species of the kind [Cu(terpy)X]+
which are isolable as their perchlorate salts. Reaction of terpyridine with excess
copper(11) perchlorate yields [Cu(terpy)-(HzO)](ClO4)2.
The water molecule can be replaced by both mono- and bi-dentate amine ligands
giving the complexes Cu(terpy)L](ClO4)2
(L = NH3, py, bipy).

Conductimetric titrations in non-aqueous solvents show that Cu(terpy)(H2O)]2+ reacts with halide ion
to give, in turn, [Cu(terpy)X]+ and Cu(terpy)X2. The bis-terpyridine
complexes [Cu(terpy)2]X2,nH2O
(X = ClO4, n = 1; X = NCS, n = 2; X = I, n = 1)
have also been prepared. [Cu(terpy)2]2+
is stable in the presence of halide ion in aqueous solution but in non-aqueous
solution rearrangement to the corresponding mono-complex Cu(terpy)X2
is instantaneous. This was confirmed by conductimetric
titrations. Reaction of terpyridine with excess copper(11) chloride affords a
complex Cuz(terpy)Cl4, which is shown to be Cu(terpy)Cl][CuCl3].
Kinetics of the direct chlorination of carbon
Authors: Blackwood JD , Cullis BD
Published: September 2010

Carbon, in the form of a
wood char activated by treatment with air and chlorine, has been
chlorinated directly at temperatures between 600� and 800� and at chlorine
pressures between 3.5 and 20 atm in a flow apparatus
to produce carbon tetrachloride as sole reaction product. The rate of formation
R of carbon tetrachloride can be expressed by the equation

R = ilpa

where il
is the rate constant for the chemisorption of
chlorine on carbon and pa is the partial pressure of chlorine. The
rate is also dependent on the nature of the carbon, high temperature carbons
being less reactive. The energy of activation for the process is 25 kcal mole-1.

When carbon tetrachloride
is decomposed in a carbon bed, tetrachloroethylene, hexachloroethane, chlorine, and carbon are formed as
products, the predominant species depending on the conditions. This indicated
that the overall reaction is not given by the simple equation

C + 2Cl2 + CCl4
(I)

and, on prolonged reaction
times, yields of carbon tetrachloride well below the amount expected at
equilibrium for this reaction confirm the finding.

pa denotes the
partial pressure of Cl2, pb that of CCl4, pc
that of C2C14, and pa that of CzCl6.The subscript numerals to i and j refer to the equation numbers in the text.
The mass spectra of oxoquinolizidines
Authors: Hussain M , Robertson JS , Watson TR
Published: September 2010

The mass spectra of quinolizidine and of 1-, 2-, and 3-oxoquinolizidine
have been determined. The suggested fragmentation patterns are supported by
high resolution measurements and deuterium labelling. It would appear that the
fragmentation patterns are mainly influenced by the nitrogen; the initial
cleavage occurs in the C-C bond which is α with respect to the nitrogen.
The Pschorr cyclization. A novel Pschorr reaction with a pyrrole derivative: synthesis of a pyrrolo[1,2-c]quinazoline and a new route to arylpyrroles
Authors: Beveridge S , Huppatz JL
Published: September 2010

The copper-catalysed
decomposition of the diazonium chloride derived from
N-(3,5 -diethoxycarbonyl -4-methylpyrrol-2-ylmethyl)-N-methanesulphonyl-o-phenylenediamine (2) gave spiro[l-methanesulphonyl - 3H-indoline -
3,2'- (3', 5'- di-ethoxycarbonyl-4-methyl-2'H-pyrrole)]
(4), in high yield. However, thermal
decomposition of the diazonium chloride gave 2,4-diethoxy-carbonyl-5-(N-methanesulphonyl-o-aminophenyl)-3-methylpyrrole (3) as the major product. The spiro compound (4)
afforded the phenylpyrrole (3) in almost quantitative
yield on treatment with concentrated hydrochloric acid, while 100% phosphoric
acid or 60% sulphuric acid converted the spiro compound (4) into
1,3-diethoxycarbonyl-5-methanesulphonyl-2-methyl-4,5-dihydropyrrolo[1,2-c]quinazoline
(12). The latter reaction could also be achieved thermally. Analytical and
spectral data are presented which support the
structures proposed.
Solvent effects on the ultraviolet absorption spectra of o-, m-, and p-Hydroxybenzylideneimines
Authors: Alexander PW , Sleet RJ
Published: September 2010

The ultraviolet absorption
spectra of the mono-salicylideneimines of ethylamine,
ethanolamine, and n-butylamine and of the bis-salicylideneimines
of ethylenediamine, trimethylenediamine,
and 1,3-diaminopropan-2-ol have been separately
examined in various solvents: water, absolute ethanol, dioxan,
and cyclohexane. A comparison of these spectra with those of the N-methylimines
of m- and p-hydroxy-benzaldehydes in similar solvents indicates that the o- and
p-hydroxybenzylideneimines exist mainly as the
dipolar keto amines in very polar, hydrogen-bonding solvents whereas the
m-isomers exist mainly as the enol imine tautomeric
form in all solvents.
Metal template reactions. II. Formation of macrocyclic quadridentate α-diimine nickel(II) complexes
Authors: Black DSC , Lane MJ
Published: September 2010

Reaction of N,N-bis(2-aminobenzylidene)ethylenediamine
with biacetyl in the presence of nickel(11)
chloride hexahydrate has yielded a compound which has
been assigned the composition chlorohydroxo-7,8-dihydro-16,17-dimethyl-

dibenzo[e,m][l,4,8,11]tetraazacyclotetradecinatonickel(11)
monohydrate. Satisfactory generalization of this reaction type has not been
achieved because of the difficulty of purification of the products and also
because of their structural complexity. The new quadridentate amine, N,N'-bis[2-(aminomethyl)phenyl]ethylenediamine,
has been prepared and this reacts with biacetyl in
the presence of nickel(11) perchlorate

hexahydrate, but the composition of the product could not be
elucidated.
Some rheological and electrokinetic properties of kaolinite suspensions
Authors: Nicol SK , Hunter RJ
Published: September 2010

The rheological behaviour of kaolinite sols has been studied as a function of pH and in the presence of adsorbates. The Bingham yield value shows a pronounced maximum at about neutral pH due, it is suggested, to the presence of extended chains of particles attached together by electrostatic interactions between edges and faces, as has been suggested by Street. At high pH values the particles behave as individuals and the yield value can be very effectively correlated with the attractive and repulsive forces between them, using the basic notions of colloid stability theory.
Adsorption of long-chain quaternary ammonium compounds on the clay surface at high pH enabled the particle interaction energy to be altered over a wide range and this adsorption itself allowed a study of the van der Waals interaction energy between the CH2 groups of the adsorbate; a value of 1.2kT was found for this latter energy, in excellent agreement with estimates based on micellization in solution.
Cyclic phosphines and arsines. III. Coordination compounds of cyclic arsines
Authors: Elmes PS , West BO
Published: September 2010

Pentamethylcyclopentaarsine displaces ethanol from M(CO)5EtOH (M = Cr, Mo, W) to yield dinuclear species [M(CO)5]2(AsMe)5 in which the cyclic arsine ring is still intact. Other displacement reactions involving the cyclic arsine and di- and tri-substituted metal carbonyl derivatives also gave compounds containing an intact arsine ring. Thermal reactions between M(CO)6 (M = Cr, Mo, W) and the arsine yield the compounds [M(CO)4(AsMe)5]2 which are bridged arsenido derivatives containing chains of arsenic atoms linking two metal atoms. The complexes [Mo(CO)3(AsEt)4]2 and [Mo(C0)4(AsEt)4]2 were both obtained in the reaction involving (AsEt)5 with Mo(CO)6.
Ion-molecule reactions of methyl fluoride and methylene chloride
Authors: McAskill NA
Published: September 2010

The ion-molecule reactions of CH3F and CH2Cl2 were examined in the gas phase using a high-pressure mass spectrometer. The ionic products of CH3F were mainly CH2F+, C2H6F+, and CH4F+. In the CH2Cl2 system the main product was CHCl2+ together with smaller amounts of CH2Cl+, CH3Cl2+, and several condensation ions. The ionic reactivity of the two compounds was compared to that of other halomethanes. Rate coefficients and reaction cross sections for many primary reactant ions were measured as a function of the ion exit energy.
Termite attractants in Santalum spicatum
Authors: Birch AJ , Chamberlain KB , Moore BP , Powell VH
Published: September 2010

The oil of Santalum spicatum (R.Br.) A.DC. has been fractionated to yield 10-cis- (1) and 10-trans-2,6,10-trimethyldodeca-2,6,10-triene (2). These compounds have been synthesized by reduction of a mixture of cis- and trans-farnesyl acetate. Although not identical with the trail pheromone of Nasutitermes they have similar specific trail activities, the former being the more active.
Fluorine-19 chemical shifts in saturated systems
Authors: Della EW
Published: September 2010

A series of cis-3 substituted trifluoromethylcyclohexanes has been synthesized and the l9F chemical shifts determined. The data reveal that in this system the field effect of sterically remote substituents has little influence on the shielding of the fluorine nucleus.
Metal template reactions. VI. Ligand substitution of neutral complexes derived from Di(2-pyridyl)amine and 1,3-Di(2'-pyridyl)-2,3-diazaprop-1-ene
Authors: Black DSC , Srivastava RC
Published: September 2010

Bis[di(2-pyridyl)aminato]palladium(II)
and bis[1,3-di(2?-pyridyl)-2,3- diazaprop-1-enato]nickel(II)
are cabaple of acting as nucleophiles: the former has been benzoylated and the
latter has been methylated, ethylated, benzylated, benzoylated, and treated with
benzenediazonium fluoroborate to yield in each case related complexes of the
variously substituted ligands.
Diterpenoids. XXVII. The selenium dehydrogenation of manool
Authors: Carman RM , Craig W
Published: September 2010

The structures of 14
products derived from the selenium dehydrogenation of manool have been
determined. The formation and disappearance of these compounds in the
dehydrogenation mixture is discussed.
The synthesis of some substituted methyl pyridinecarboxylates. II. Methyl 4-substituted picolinates, methyl 5-substituted picolinates, and methyl 5-substituted nicotinates
Authors: Deady LW , Shanks RA , Campbell AD , Chooi SY
Published: September 2010

General methods are
described for the synthesis of three series of substituted methyl
pyridinecarboxylates from readily available starting materials. Methyl
4-X-picolinates and methyl 5-X-picolinates (X = NO2, Br, MeO, Me2N)
are prepared from 2-picoline via 4-nitro-2-picoline N- oxide and
2-amino-5-nitropyridine respectively. Methyl 5-X-nicotinates (X = Br, MeO, Me2N)
are prepared from 5-bromonicotinic acid. Preparations of methyl
4-methylpicolinate and methyl 5-methylnicotinate from the corresponding lutidines
and methyl 5-methylpicolinate from 2-amino-5-methylpyridine are described.
N-Unsubstituted 1,2,4-Triazole-3-carbaldehydes
Authors: Browne EJ
Published: September 2010

A series of N-unsubstituted
1,2,4-triazole-3-carbaldehydes has been prepared by acid hydrolysis of their
methyl or ethyl acetals. Those with 5-aryl substituents have been shown to dimerize
in the solid state to carbonyl-free hemiaminals. P.m.r.
and infrared spectra indicate that monomeric 1,2,4-triazole-3-carbaldehydes are
present in solution, the dimers being reformed on removal of the solvents.
Parallels are drawn with benzimidazole-2-carbaldehyde, to which a similar
structure has been assigned. With non-aromatic 5-substituents the hemiaminal
becomes less stable, and 1,2,4-triazole-3-carbaldehyde, itself, exists
predominantly in the carbonyl form. Mass spectra were consistent with
essentially normal aldehyde structures.
The configuration of alkylidenephthalimidine derivatives
Authors: Ang WS , Halton B
Published: September 2010

The configuration of
several alkylidenephthalimidines, formed by
dehydration of 3-alkyl-3-hydroxyphthalimidines, has
been established by nuclear magnetic resonance techniques. When the nitrogen
substituent is alkyl or aryl the configuration is (E) but when hydrogen it is
(Z). Isomerization was observed in the temperature range 60-140�.
The evaluation of thermodynamic functions from aqueous solubility measurements
Authors: Alexander DM , Hill DJT , White LR
Published: September 2010

Aqueous solubility
measurements for a number of non-electrolyte solutes have been analysed using a
statistical method of curve fitting to yield the best unbiased estimates of the
thermodynamic function changes on solution. The variation of partial molar heat
capacity changes with temperature has been discussed.
Octaisopropyloctasilsesquioxane, brominated octaisopropyloctasilsesquioxanes, and their reactions
Authors: Bishop JH , Shaw RA
Published: September 2010

Some reactions of octaisopropylpentacyclo(9,5,1,13,9,15,15,1
7,18)octasiloxane (octaisopropyl-T8)
and its brominated derivatives have been investigated. The isolation of
compounds (C8H6Br)n(C3H7)8-n(SiO1.5)8
(n = 1, 2, or 3) is reported. Dehydrobromination of α-brominated
octaisopropyl-T8 compounds yields isopropenyl-T8
derivatives. Bromine addition to the latter occurs. The high resolution p.m.r. spectra of octaisopropyl-T8 derivatives
are discussed.
N-Nitroso-L-4-hydroxyproline as a precursor of intermediates for peptide synthesis
Authors: Stewart FHC
Published: September 2010

The N-nitroso derivative of
L-4-hydroxyproline has been converted into various esters and other
intermediates intended for use as coupling components in peptide synthesis. The
preparative approach involved selective acidic cleavage of nitroso in the presence
of different carboxyl-protecting groups, including the acid-labile 2,4,6- trimethylbenzyl
moiety. Practical application of the new intermediates was illustrated by
representative syntheses of crystalline protected L- 4-hydroxyproline peptides.
2-Substituted and 2,6-disubstituted 1,4-benzoquinone 4-oxime acetates
Authors: Norris RK , Sternhell S
Published: September 2010

The preparation and
physical properties of 19 compounds in the title series are described. The
acetates were prepared by treatment of the corresponding benzoquinone oximes or
p-nitrosophenols with acetic anhydride in the presence of catalytic amounts of pyridine.
The syn and anti isomers can be equilibrated in
acetic anhydride solutions containing traces of sulphuric acid. The effect of
substituents at C2 on the position of the syn-anti
equilibria is very similar to their effect in the corresponding 1,4-benzoquinone
4-oximes. N.m.r. parameters, electronic and infrared data, photochemical syn-anti conversions, and the probable mechanism of the
acid-catalysed equilibration are discussed.
Mass spectrometry of the vapours over PbBr2+MBr mixtures (M = Na, K, Rb, Cs)
Authors: Bloom H , Anthony RG
Published: September 2010

A mass spectrometric study
of vapours above molten PbBr2+MBr mixtures has revealed the
existence of vapour species of general formula MPbBr3 (M = Na, K,
Rb, Cs). Second-law enthalpies of formation of these complexes were found to be
in the range -39 to -44 kcal/mol; entropies of formation are estimated between
-20 to -21 e.u. It is believed that these complex molecules have a bipyramidal
structure.
Octahedral cobalt(III) complexes of the chloropentammine type. XXIII. The mercury(II)-induced aquation of some cis-Chloropyridinebis(ethylenediamine) cobalt(III) complexes
Authors: Chan SC , Chan SF
Published: September 2010

The second-order rate
constants for the mercury(II)-induced aquation of some cis-chloropyridinebis(ethylenediamine)cobalt(III)
cations have been measured in aqueous solution over a range of temperatures.
The results are interpreted in terms of the formation of an activated complex
Co-Cl-Hg, which yields the aquo
product by a unimolecular aquation with HgCl+
as the leaving group. The competitive influences of the steric and inductive
effects of alkyl substituents are discussed.
The structure of squamulosone, a new sesquiterpene ketone from Phebalium squamulosum
Authors: Batey IL , Hellyer RO , Pinhey JT
Published: September 2010

Squamulosone, C15H22O,
a new sesquiterpene ketone occurring in Phebalium squamulosum, has been shown
to have the structure (1) on chemical and spectroscopic evidence.
Deceptive simplicity in ABMX N.M.R. spectra. II. Assignment and inter-ring coupling in dibenzothiophen and its S-oxides
Authors: Balkau F , Heffernan ML
Published: September 2010

The assignment of the
chemical shifts of dibenzothiophen is presented as well as an analysis of the
spectra of the sulphoxide and sulphone. A small inter-ring coupling exists in
these compounds and also in dibenzoselenophen. The solvent dependence of the chemical
shifts of dibenzothiophen has been briefly investigated but cannot be explained
in simple terms.
Synthesis of o-isopentenylphenols
Authors: Hlubucek J , Ritchie E , Taylor WC
Published: September 2010

The effect of the solvent
and the counter-ion on the ring alkylation of 3- and 4-methoxyphenols by
isopentenyl bromide has been examined. Under strictly anhydrous conditions good
and consistent yields of the o- isopentenylphenols were obtained with the combination
potassium- toluene, but sodium-toluene was more convenient. ��� Boron trifluoride etherate was more
satisfactory than stannic chloride, zinc chloride, or phosphoric acid in
catalysing the condensation of 3- and 4-methoxy-phenols with 2-methylbut-3-en-2-ol
to the corresponding o-isopentenylphenols. Aryl α,α-dimethylpropargyl
ethers were partially hydrogenated to the corresponding α,α- dimethylallyl
ethers which rearranged in boiling N,N-diethyl-aniline to o-isopentenylphenols
in high overall yield.
Thermodynamics of metal-ligand bond formation. IV. Base adducts of Bis(ethylxanthato)nickel(II) and Bis(dialkyldithiophosphato)nickel(II)
Authors: Dakternieks DR , Graddon DP
Published: September 2010

The reactions of pyridine with bis(ethylxanthato)nickel(~~) and bis(dipropy1-
dithiophosphato)nickel(~~) and of pyridine, 4-methylpyridine, bipyridyl, and
2,9-dimethyl-l,l0-phenanthroline with bis(diethyldithiophosphato)nickel(~~) have
been studied by thermometric titration in benzene solution a t 30�C. The
xanthate adds two molecules of pyridine simultaneously, AHolz = -75 kJ mol-1,
ASOlz = -186 J K-1 mol-1. With the dithiophosphates, two molecules of base are
added in distinct steps; the enthalpy of addition of bipyridyl is similar to that
of two molecules of pyridine, but the enthalpy of addition of 2,9-dimethyl-l,l0-
phenanthroline is much smaller. The thermodynamic data obtained for these
reactions are as follows (AH" in k J mol-1, AS0 in J K-1 mol-1) :
dipropyldithiophosphate with py AHol -71, AS01 -211, AHoz 4-2, AS0$ +34
diethyldithiophosphate PY -73 -218 +4 + 40
diethyldithiophosphate 4-mepy - 83 -248 + 7 + 59
diethyldithiophosphate bipy -76
diethyldithiophosphate Mesphen -47
Determination of the magnetic susceptibility in benzene solution containing
varying pyridine concentrations has shown that base adducts of the dithiophosphates
of both the types NiLzB and NiLzBz have the metal atom in the high-spin
configuration.
Carbonyl halides of the Group VI transition metals. XXV. Complexes with the tritolylphosphines
Authors: Bowden JA , Colton R
Published: September 2010

The reactions of the
halocarbonyls M(CO)4X2 [M = Mo, W; X = Cl, Br,I] with the three tolylphosphines (ortho, meta, and para) have been
investigated. The variation observed in the nature of the reactions and
properties of the products has been explained in terms of a steric effect. The oxidation of trans-M(CO)4(PPh3)2 with halogen,
and the reactions of triphenylphosphine with M(CO)4I2,
have been reinvestigated along with a study of the corresponding reactions for
the tritolylphosphines. Mechanisms for these reactions have been
proposed.
The infrared spectra of rhenium and osmium oxide tetrachlorides in the gas phase, condensed phase, and in solution
Authors: Barraclough CG , Kew DJ
Published: September 2010

The infrared spectra of
ReOCl4 and OsOCl4 have been measured in the gas phase, in the condensed
phase, and in a variety of solvents. In the gas phase spectra
the absorption band envelopes corresponding to the metal-oxygen stretching
vibrations have been observed and the data are discussed in terms of possible
square pyramidal or trigonal bipyramidal structures for the molecules. Evidence
is presented showing that acetone and diethyl ether molecules will readily
coordinate to these oxide tetrachlorides when
dissolved in inert solvents. The effect of traces of water on the same
solutions is also described and discussed. Both ReOCl4 and OsOCl4
react with the solvent if dissolved in acetone or diethyl ether and the
possibility of the formation of the unknown oxide trichlorides
is discussed.
Organomercury compounds. XIII. The mercuration of 1,2,4,5-tetrafluorobenzene
Authors: Albrecht HB , Deacon GB
Published: September 2010

2,3,5,6.Tetrafluorophenylmercuric
trifluoroacetate and acetate, 1,4-bis(tri-fluoroacetatomercuri)tetrafluorobenzene,
and 1,4-di(acetatomercuri)tetraffuorobenzene have been prepared by mercuration
of 1,2,4,5-tetrafluorobenzene with mercuric trifluoroacetate or acetate while
2,3,5,6-tetrafluorophenglmercuric chloride and acetate,
1,4-di(chloromercuri)tetrafluorobenzene, and 1,4-di(acetatomercuri)tetrafluorobenzene
have been obtained from the corresponding trifluoroacetates by metathesis
reactions. The di(chloromercuri) derivative has also been isolated from
reaction of thallous tetrafluoroterephthalate with mercuric chloride. Bis(2,3,5,6-tetrafluorophenyl)mercury
has been prepared by rearrangement of 2,3,5,6-tetrafluorophenglmercuric
trifluoroacetate with iodide ions, and by mercuration of
1,2,4,5-tetrafluorobenzene with tetrabromomercurate(11) ions under alkaline
conditions. The latter reaction also gave a low yield of
1,4-bis(2,3,5,6-tetrafluorophenylmercuri)tetrafluorobenzene, which was
identified by N.M.R. spectroscopy, and by degradation with mercuric chloride.
The carbon-oxygen stretching frequencies of the new organomercuric carboxylates
are indicative of unidentate carboxylate coordination.
Studies of oxidations by Fenton's reagent using redox titration. II. Effect of oxygen
Authors: Ingles DL
Published: September 2010

The effect of oxygen on
oxidations by Fenton's reagent has been studied by redox titration at constant
oxidation potential. The reactivity of substrate radicals towards oxygen has
been assessed. The peroxide requirements for the complete oxidation of substrate
in the absence and presence of oxygen have been compared. The extent of
oxidation of different substrates was determined by gas chromatography and the
results indicated the occurrence, in oxygen, of nem chain reactions.
The chemistry of pyrrolic compounds. XVIII. Hydrogenation of meso-acetoxyporphyrins: meso-acetoxychlorins
Authors: Clezy PS , Diakiw V , Liepa AJ
Published: September 2010

The hydrogenation of meso-acetoxyporphyrins
which are unsubstituted in four neighbouring positions
yields meso-acetoxychlorins.
The degree of substitution and the size of each substituent determines the
product ratio of meso-acetoxychlorin
to meso-unsubstituted
porphyrin. Attempts to obtain the meso-hydroxychlorin system by hydrolysis of the acetate were
unsuccessful.
Denaturation of proteins. IV. N.M.R. studies of ribonuclease-A
Authors: Bradbury JH , King NLR
Published: September 2010

The denaturation
of ribonuclease-A by the addition of urea, guanidine hydrochloride, formic acid,
and potassium thiocyanate to solutions in water or D2O at 33� has
been followed by nuclear magnetic resonance (N.M.R.) spectroscopy. ��The complex N.M.R. spectra at low field can
be simplified greatly by a difference spectrum obtained by subtracting the
spectrum obtained in deuterium oxide from the corresponding spectrum in water,
whence the resonances of protons attached to nitrogen are isolated. Binding of
urea and guanidine hydrochloride at concentrations well below that needed for
unfolding is shown by modification of the C2 histidine resonances due to the histidines located at positions 12 and 119. This confirms
that these denaturants inactivate the enzyme by binding at its active site as
proposed by Barnard.The unfolding of ribonuclease by urea and guanidine hydrochloride at acid pH
is shown to be a two-state process in which the fraction of unfolded molecules
(cross-linked random coils) is calculated directly from the relative increase
in heights of the various n.m.r, resonances. The unfolding in [D2]formic acid
is characterized by the first (major) transition with a midpoint at 8% [D2]
formic acid (v/v) and a second (minor) transition centred at 58% [D2]formic
acid. In pure formic acid there is evidence of
aggregate formation. An intermediate form characterized by a double methionine SCH3 resonance occurs during the
first transition. There are therefore a minimum of five different states
present during this unfolding. The major unfolding process produced by
potassium thiocyanate is followed by a refolding to a non-native ordered form.
This unfolding process is incomplete and three different
Hydrolysis of amides. VI. Dilute acid hydrolysis of N-alkyl substituted acetamides
Authors: Bolton PD , Ellis J , Frier RD , Nancarrow PC
Published: September 2010

Enthalpies and entropies of
activation have been derived from rate constants measured over a range of
temperature for the dilute acid hydrolysis of N-methyl- acetamide, N-ethylacetamide, N-n-propylacetamide, N-isopropylacetamide, N-n-butylacetamide,
N-s-butylacetamide,
N-isobutylacetamide, N-isopentyl-acetamide, N-n-hexylacetamide,
N-cyclohexylacetamide,
and N-benzylacetamide.
An analysis of the rate data in terms of several Taft-type linear free energy
relationships indicates that the change in steric environment which a
substituent experiences when it is moved from the acyl part to the alkyl part
of an amide is quantitatively similar to the change in steric environment
experienced by the same substituent in moving from the acyl to the alkyl
portion of an ester. Evidence is also presented that the change in six-number
makes the greatest contribution to the change in steric environment.
Mass spectra of 1,2,4-Rriazoles. I. Methyl- and Phenyl-1,2,4-triazoline-5-thiones
Authors: Blackman AJ , Bowie JH
Published: September 2010

The mass spectra of the
monomethyl and monophenyl derivatives of 1,2,4-triazoline-5-thione
are reported and discussed. The fragmentation patterns of these compounds are
complex, and the investigation was aided by 2H, 15N, and 15N-2H
labelling, metastable defocusing, and high-resolution studies.
The pyrolysis of pinanes. V. The pyrolysis of 10α- and 10β-Pinan-2-ols and 2-Hydroxy-10β-pin-3-ene
Authors: Coxon JM , Garland RP , Hartshorn MP
Published: September 2010

The gas-phase pyrolyses of 10α- (1) and 10β-pinan-2-ol (2), and 2-hydroxy-10β-
pin-3-ene (17) are described. The effect of the introduction of a Δ3 double bond on
the course of the reaction and the mode of formation of the products is discussed.
Pyrolysis of aryl azides. II. Naphthyl azides
Authors: Boshev G , Dyall LK , Sadler PR
Published: September 2010

Kinetic studies of the pyrolyses of 1- and 2-naphthyl azides reveal neighbouring
group participation by nitro and phenylazo
substituents. The acceleration observed in 1-nitro-2-naphthyl azide, 1-phenylazo-2-naphthyl
azide, and 2-nitro-1-naphthyl azide is 1730-, 211-, and 23.6-fold,
respectively, in nitrobenzene solution at 120�. These effects are all
smaller than that of the 2-nitro group in phenyl azide (3370-fold), which is
ascribed to the steric effect of the peri hydrogen at
C8 in naphthyl azides. The sizes of these
neighbouring group effects correlate with the success of oxidative cyclization
of ortho-substituted naphthylamines with (diacetoxyiodo)benzene.
Coumarins as ligands. Studies on metal complexes of 8-Amino-7-hydroxy-4-methylcoumarin and 7-Hydroxy-4-methylcoumarin-6-carboxylic acid
Authors: Rastogi DK
Published: September 2010

Some platinum and rare
earth metal complexes of 8-amino-7-hydroxy-4-

methylcoumarin, viz. Na2[R~(C10H2NO3)Cl4],H2O,
[Ir(C10H8N03)2(0H)(H20)],-
3H20, [Ce(C10H8NO3)3(H2O)2I,6H2O,
and [Pr(C10H8N03)3(H20)2],8H2O,
and 7-hydroxy-4-methylcoumarin-6-carboxylic
acid, viz. [Pd(CllH7O5)2], [Ce(CllH705)3-
(H20)2],3HzO, and [Pr(CllH7O5)3(H2O)2],
have been studied. These complexes have been isolated and characterized by
analyses, conductometric, magnetic, and spectroscopic
studies. An octahedral stereochemistry has been assigned to these complexes
except for the PdII complex which has a
typical square-planar stereo- chemistry. The visible
spectra of the PrIII complexes show
characteristic f-f transitions and the nephelauxetic
effect (1-β) of these transitions has been evaluated.
Copper(II)-oxime complexes: A structural and spectroscopic study for a diamine dioxime ligand
Authors: Fraser JW , Hedwig GR , Powell HKJ , Robinson WT
Published: September 2010

The preparations are
reported for copper(11) complexes with the ligand 4,4,9,9-tetramethyl-5,s-diazadodecane-2,l-dione
dioxime, LH2. Syntheses from the syn
(methyl) and anti isomers of the
ligand give the same products. The complexes characterized are Cu(LH2)X2,yH2O
(X = Cl-, ClO4-; y = 0, 1, 2) and Cu(LH)X (X = Cl-, Br-,
ClO4-). The complex Cu(LH)Br is shown by X-ray structure analysis to
contain dimeric units (Cu(LH))22+ with crystallographic C2
symmetry and with the copper atom in a trigonal bipyramidal coordination
environment. Stability constants for the reactions Cu2+ + LH2 ←→
Cu(LH2)2+ (log K = 13.24 � 0.05) and Cu(LH2)2+
←→ Cu(LH)+ + H+
(log K = -3.24 � 0.08) are reported, as well as the magnetic susceptibilities, i.r. spectra, and electronic absorption spectra of the
complexes.
The effects of electronic buttressing on the conformations of some orthodisubstituted benzenes
Authors: Herrmann RI , Rae ID
Published: September 2010

When one of a pair of
substituents ortho to each other on a
benzene ring is conjugated with an appropriate para substituent, it is pulled towards coplanarity
with the aromatic ring and the other substituent has to take a greater share of
the twisting necessary to avert steric conflict. This effect, termed electronic
buttressing, is demonstrated in the proton magnetic resonance spectra of
5-dimethylamino-2- nitroanilines, 5-substituted
methyl 2-nitrobenzoates, and 4-substituted 1,2-dinitrobenzenes. In this latter
group the size of the effect is shown to depend on the conjugative ability of
the 4-substituent.
Madagascarin, a New Pigment From the Leaves of Harungana madagascariensis
Authors: Buckley D , Ritchie E , Taylor W , Young L
Published: September 2010

Extraction of the leaves of
Harungana madagascariensis
Poir. (Guttiferae) gave β-sitosterol,
quercetin, diisopropyl 4,4'-methylenedicarbanilate
(probably an artefact), and a new pigment, madagascarin. Mainly by spectroscopic methods the structure
of the latter was established as 2,7'-biemodyl (1,3,8,l?,6',8'-hexahydroxy- 6,3'-dimethyl-2,Z'-bianthraquinone).
The reaction of phenyliodoso acetate with substituted acetanilides in the presence of perchloric acid
Authors: Johnson WD , Sherwood JE
Published: September 2010

The reaction of phenyliodoso acetate with substituted acetanilides appears
to be quite complex in the presence of perchloric
acid. Although there is no change in the reaction products (at least
initially), there is evidence for a change in mechanism on the addition of
acid. Experimental evidence suggests that the reaction involves an electrophilic
substitution-yielding an acetoxy derivative in the case of p-methyl and p-methoxy
compounds.
The Alkaline Hydrolysis of Some Lignin Model 2-Arylcoumarans
Authors: Wallis AA
Published: September 2010

Reaction of the
2-arylcoumaran (2b) with 2b sodium hydroxide at 170� gave predominantly the (E)-
and (2)-stilbenes (4a) and (5a) in the ratio 1 : 2,
and the 2-arylbenzofuran (6) as a minor product. The isomeric
1,2-diarylpropan-1-ols (7b) and (8b) were prepared and gave on treatment with 2N
sodium hydroxide at 170� an analogous mixture of stilbene
isomers to that obtained from the coumaran (2b). The
mechanism of formation of compounds (4a), (5a), and (6) is discussed.
The nature of the copper(II) complexes of Pyridine-2-carbaldehyde oxime with the metal-to-ligand ratio of 1 : 1
Authors: Hoskins BF , Vince DG
Published: September 2010

No abstract available
Preparations of organonickel compounds by thermal decomposition of nickel carboxylates
Authors: Cookson PG , Deacon GB
Published: September 2010

The carboxylatonickel(11)
compounds, (RCO2)2 NiL,αH2O [R = C6F5,
p- MeOC6F4,
or p-EtOC6F4; L
= 2,2'-bipyridyl (bipy), α = 2, or L = 1,l0-hen-anthroline
(phen), α = 1], have been obtained from reactions of nickel carbonate, the
appropriate carboxylio acids, and the bidentate
nitrogen ligands in aqueous ethanol. Nickel has octahedral stereochemistry, and
possible structures are discussed. Decomposition of the
complexes in boiling toluene, except for C6F5CO2)2X(phen),H2O
when boiling benzene with added benzoyl peroxide was
used, gave the corresponding organonickel compounds, R2NiL. The formation of the α-substituted
phenanthroline derivatives, R2NiL'[R =
p-MeOC6F4 or p-EtOC6F4;
L' = 2-(p-alkoxytetrafluorophenyl)-1,l0-phenanthroline]
and (p-MeOC6F4),NiL" [L"
= 2,9-bis(p-methoxytetrafluorophenyl)-1,l0-phenanthroline],
accompanied the preparations of the appropriate R2NiL compounds. The
stereochemistry of nickel in the organonickel derivatives is approximately
planar.
Crystal and molecular structure of 4α-t-Butylcyclohexane-1β,2β-diol
Authors: Brice MD , Penfold BR , Robinson WT
Published: September 2010

The crystal and molecular
structure of 4α-t-butylcyclohexane-1β,2,β-diol, C10H20O2,
has been determined by X-ray diffraction methods. The compound crystallizes in
the triclinic space group Pi with 4 molecules in a unit cell of dimensions a = 12.268, b = 15.921, c = 6.322�, α
= 82.53, β = 114.45, γ = 111.13�. The intensity data were measured by
counter methods using Cu Kα radiation; the
structure was solved by means of the tangent formula, and was refined using
full matrix least-squares techniques to a final R-factor of 0.063 for 1199
reflections. The crystal structure
consists of two sets of crystallographically non-equivalent molecules
hydrogen-bonded to form discrete chains parallel to the c axis. The cyclohexane
rings are in the chair conformation.
The pyrolysis of pinanes. VIII. The pyrolysis of some pinanones
Authors: Coxon JM , Garland RP , Hartshorn MP
Published: September 2010

The gas-phase pyrolyses of cis-verbanone (1), isopinocamphone (2),
and nopinone (3) are described.
Synthetic studies related to mycobactins. III. Approaches to the synthesis of the cobactin ring system
Authors: Black DSC , Brown RFC , Wade AM
Published: September 2010

The synthesis of several
seven-membered cyclic hydroxamic acids has been
carried out in low yield. Reduction of diethyl 2-hydroxyiminoheptane-l,7-dioate
afforded ethyl 1-hydroxy-7-oxohexahydroazepine-2-carboxylate, together with
related acyclic products. The cobactin precursor
3-bromo-1-hydroxyhexahydro-azepin-2-one was obtained
by the ring expansion of 2-bromocyclohexanone with benzenesulphonohydroxamic
acid and also by the peracid oxidation of 6-bromo-7-ethoxy-3,4,5,6-tetrahydro-2H-azepine. The methyl and cinnamyl
imidates of hexanolactam
were oxidized by peracid to
1-hydroxyhexahydroazepin-2-one, in addition to the related imino-
and nitroso-hexanoic esters. In a similar reaction, 1-hydroxypiperidin-2-one was obtained from 2-methoxy-3,4,5,6-tetrahydropyridine. During the course of these
oxidation reactions, the intermediate oxaziridines 7-methoxy-8-oxa-1-azabicyclo[5,1,0]octane and 6-bromo-7-ethoxy-8-oxa-1-azabicyclo[5,1,0]octane were isolated and identified.
The peraoid oxidation of ethyl N-cyclohexylbenzimidate yielded cyclohexylhydroxylamine and ethyl benzoate in reasonable
yields. This reaction suggests a useful method for the conversion of a primary
amine into the related hydroxylamine.
Tris(dithioacetylacetonato)chromium(III)
Authors: Heath GA , Martin RL , Masters AF
Published: September 2010

The synthesis of the first dithioaoetylacetonate of a Group VI transition metal has
been achieved by reduction of the 3,5-dimethyl-1,2-dithiolium
cation with divalent chromium. The physical properties of the dark green
monomer [Cr(SacSac)3] are reported.
The aggregation of the tetrasodium salt of copper phthalocyanine 4,4',4',4''-tetrasulphonic acid
Authors: Blagrove RJ , Gruen LC
Published: September 2010

The aggregation of the tetrasodium salt of copper phthalocyanine-4,4',4",4???
tetrasulphonic acid has been investigated by
equilibrium spectrophotometric measurements at 25�. At low concentrations this
can be treated in terms of a monomer-dimer equilibrium. Owing to the strong
aggregating tendency of this molecule in water, it was necessary to evaluate
the dissociation constant together with the monomer and dimer spectra from
measurements made in 20% ethanol solutions. By means of these data, the
corresponding dissociation constant in water has been determined.
Oxidation of dithiocarbamato metal complexes
Authors: Golding RM , Harris CM , Jessop KJ , Tennant WC
Published: September 2010

Cationic dithiocarbamato complexes of the type [Cu(dtc)2]X,
[Fe(dtc)a]X3 and [Ni(dtc)3]X (where dtc refers to the
dithiocarbamate ligand and X to the non-coordinating anions perchlorate and tetrachloroferrate(111)) which function as uni-univalent electrolytes in nitrobenzene, have been prepared
by the reaction of iron(111) chloride and iron(111) perchlorats
with copper(11), iron(111), and nickel(11) dithiocarbamates
and copper(11) perchlorate with copper(11) dithiocarbamates.
Magnetic susceptibility,
N.M.R., M�ssbauer, infrared, and visible-ultraviolet
spectral data are reported for these complexes.