bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral and structural studies of 4-aminopyridines substituted at the 4-nitrogen atom. 4-Nitraminopyridine, 4-hydrazinopyridine, and theirions
Authors: Batts BD , Spinner E
Published: September 2010

Ultraviolet, infrared, and
nuclear magnetic resonance spectra, and ionization constants, have been
determined for 4-nitraminopyridine, 4- (methylnitramino)-pyridine,
1,4-dihydro-1-methyl-4-nitriminopyridine, 4-hydrazinopyridine, 1,4-dihydro-1-methylpyridin-4-one
hydrazone, and their ions. 4-Nitraminopyridine exists in the nitrimine
tautomeric form (II) in the solid state, in water (in c. 99%), ethanol,
dimethyl sulphoxide, and acetonitrile, but in dioxan it is mostly (c. 94%) in
the nitramino form (I). 4-Hydrazinopyridine exists predominantly in the
hydrazine form. ��� Infrared spectra characteristic of
pyridinium ions are shown by the cation of 4-nitraminopyridine (X) and the
dication of 4- hydrazinopyridine (XIV); in both the ring nitrogen carries a
positive charge. The infrared spectrum of the monocation of 4-hydrazinopyridine
is not that of a pyridinium ion, and shows 4-pyridonoid features; the positive
charge resides essentially on the 4-nitrogen atom (XIII), as in the
unsubstituted 4-aminopyridine cation. ��� Cation formation moves the a- and β-proton
magnetic resonances of both 4-(methylnitramino)pyridine and
1,4-dihydro-1-methyl-4- nitriminopyridine to substantially lower 7 values.
Monocation formation reduces the T value of the β-proton
resonance of 4-hydrazinopyridine by a relatively small amount, and changes that
of the a-proton only slightly (upward). Formation of the dication of
4-hydrazino-pyridine (XIV) lowers both T values substantially.
An electron spin resonance study of pure anthracene doped with alkali metals
Authors: Bien VC , Lyons LE
Published: September 2010

When pure anthracene is melted under a pure nitrogen atmosphere in
the presence of an alkali
metal, the metal dissolves forming a blue-green melt which exhibits an electron
spin resonance (e.s.r.) signal. The polycrystalline samples of the solid system
(MAn) obtained by cooling the melt also exhibit e.s.r, signals but with a line-width greater than that seen
in the melt. The Lorentzian
line-shapes in the solid and the melt indicate that the electrons producing the
signals are either delocalized, or clustered and undergoing exchange
interaction. The following features are
discussed: the lack of hyperfine structure in the melt except for a special
case; the Curie dependence of the susceptibility; the dependence of the
g-values on the alkali metal; the shifts of the g-values on melting the
samples; the behaviour of the line-width with respect to deuteration
of anthraoene and with respect to the different
alkali metals; and the dependence of the spin-lattice relaxation time on the
alkali metal and on whether the sample was solid or molten. The features
indicate that the electrons behave as simple doublets, are clustered with the
alkali-metal complex in the solid and undergo exchange interaction, produce
motional narrowing of lines in the melt, and produce a line-width mainly
dependent on the alkali metal ions in the solid and to a lesser extent in the
melt.
Carbonyl halides of the Group VI transition metals. XIX. Iodocarbonyl complexes of molybdenum and tungsten with Bis(diphenylarsino)methane
Authors: Colton R , Rix CJ
Published: September 2010

Complexes of the general
formulae M(CO)3(dam)I2, M(CO)3(dam)2I2,
and M(CO)2(dam)2I2
have been prepared and characterized [M = Mo, W; dam = bis(diphenylarsino)methane].
All of the compounds are diamagnetic and non-electrolytes in acetone solution.
The tungsten derivatives were prepared by direct interaction of dam with diiodotetracarbonyltungsten(11), but the molybdenum
analogues were obtained by iodine oxidation of the zero-valent
complex Mo(CO)4(dam)2 whose preparation is
reported for the first time in this paper. The bis(dam)tricarbonyl
complexes, M(C0)3(dam)2I2, are unstable in
solution giving M(CO)2(dam)I2 and free dam in equilibrium
with undissociated complex. The bis(dam)tricarbonyl
complexes also readily lose carbon monoxide, especially in the case of
molybdenum, to give M(CO)z(dam)2I2. These
dicarbonyl complexes readily absorb carbon monoxide to re-form the tricarbonyl
complexes to give a reversible carbon monoxide carrying system. Overall, these
systems may be represented by the general equations :

M(CO)3(dam)I2 + dam ↔ M(CO)3(dam)2I2
+ CO

These equilibria
have been studied using both infrared and nuclear magnetic resonance
techniques.
Dithiocarbamates of titanium(III)
Authors: Coutts RSP , Wailes PC , Kingston JV
Published: September 2010

Several N,N-dialkyldithiocarbamates
of bis(cyclopentadienyl)titanium(111) have been
prepared from cp2TiCl (cp = π-cyclopentadienyl) and sodium diallryl-dithiocarbamates
under inert atmosphere. The bright green air-sensitive compounds are
paramagnetic with one unpaired electron per titanium atom. Their formulation as
monomeric, symmetrical bidentate chelate complexes

(See diagram in article)

has been established from
spectral, magnetic, and molecular weight data.
Coordination compounds of substituted 1,10-phenanthrolines and related bipyridyls. XI. Physicochemical study of complexes of copper(II) and 2-Methyl-1,10-phenanthroline
Authors: Ainscough EW , Plowman RA
Published: September 2010

Solutions of 2-methyl-1,10-phenanthroline (rnep) with excess copper(II) salts in
organic solvents yielded complexes of the formula Cu(mep)X2 (X = NO3, Cl, Br, I).
These were non-electrolytes in nitrobenzene. When excess rnep was present bis-
complexes of the type Cu(mep)2Cl2,6H2O, Cu(mep)2/sub>(NO3)2,H2O, and hydrated forms
of the type Cu(mep)2XClO4 (X = Cl, NO3) were obtained. These were 1 : 1
electrolytes in nitrobenzene and the copper(II) ion was at least five-coordinated with
the donor nitrogen atoms taking up a flattened tetrahedral arrangement. Hydrated
copper(II) perchlorate with rnep in a 1 : 2 or 1 : 1 ratio yielded Cu(mep)2(ClO4)2,2H2O
which is a 2 : 1 electrolyte in nitrobenzene. From a water solution of copper nitrate
and rnep in the ratio 1 : 3.5, a complex Cu(mep)3(ClO>sub>4)2 precipitated upon the
addition of a sodium perchlorate solution. I t was thought previously that this
compound did not exist. The magnetic susceptibilities, the conductivities, and the
visible, absorption, and infrared spectra of some rnep complexes have been obtained
and structures are proposed from this information.
Octahedral cobalt(III) complexes of the chloropentammine type. XX. The preparation, properties, and reactions of some chlorocycloalkylaminebis- (ethylenediamine)cobalt(III) salts
Authors: Chan SC , Cheung TL
Published: September 2010

Salts of one isomeric form
of the chlorocycloalkylaminebis(ethylenediamine)cobalt(111)
series of cations have been prepared and characterized. They are tentatively
assigned a cis configuration on the basis of visible absorption spectroscopy.
The first-order rate constants
for the solvolytic aquation
of these cations have been determined at 50.5�, and the results suggest the
presence of steric acceleration. The second-order rate constants for the base
hydrolysis of these cations have also been determined at 0� and ionic strength
of 0.1M. These results are discussed in terms of the conjugate-base/ion-pair
mechanistic spectrum postulated previously.
Crystal field spectra of d3,7 ions. VI. The weak field formalism and covalency
Authors: Ferguson J , Wood DL
Published: September 2010

When the problem of an ion
in a crystal field is solved using the unperturbed atomic wave functions as
basis functions, the free ion energies appear explicitly in the diagonal terms
of the secular determinant where they can be adjusted as experimental parameters.
By fitting the observed crystal field energy levels in this scheme, a set of modified free ion
energy levels can be derived for Dq = 0, and it is
found that in most cases a single set of electrostatic repulsion parameters F2
and F4 describes the energies, provided a Trees correction is
applied. The values of F2 and F4 obtained in this way
from crystal spectra of Cr3+ in
ruby, yttrium gallium garnet, other oxides, and K3Cr(CN)6
and of Co2+ in ZnAl2O4 are reduced by covalency from their free ion values. The reduction for P2
is greater than for F4 because of its greater sensitivity to the
outer part of the radial distribution function, where covalency
plays its major part. It is concluded that the differential expansion of the t2
and e orbitals in the crystal field is not great, and
that nephelauxetic effects in crystal field spectra should more properly be
related to the F2 and F4 parameters of Condon and Shortley through the weak field formalism, rather than to Racah's B parameter in the strong field approach. The
latter results in unsound conclusions about the effects of covalency.
Analysis of the spectra of CrBrs and C0C14"
suggests that the d electrons are not adequately described by two electrostatic
repulsion parameters and the usual crystal field theory should be applied
cautiously.
The role of trifluoromethyl radicals in the radiation polymerization of gaseous tetrafluoroethylene
Authors: Cooper R , Roy CR
Published: September 2010

Mass spectral analysis of
the solid polymer produced by radiolysis of gaseous tetrafluoroethylene reveals
significant initiation by CF3 species. In the presence of nitric
oxide, CF3NO is produced [G(CF3NO) = 3.11] and
polymerization is completely inhibited. The scavenging of CF3
radicals by NO in this system yields rate constant data consistent with
available data for photochemically produced CF3 radicals. The mass
spectrum of pure C2F4 contains a metastable peak,
indicating that an ionic rearrangement
of C2F4 produces CF3+.
Ion-molecule reactions producing CF3 ions and radicals can produce
up to 1.17 per ion pair; the observed yield is 1.02 � 0.05. 3-Methylpentane,
acting as a charge-transfer agent, inhibits polymerization.
Antioestrogenic and antifertility compounds. III. Enantiomers of (±)-hexoestrol and its homologues
Authors: Collins DJ , Hobbs JJ
Published: September 2010

(�)-2,3-Bis(p-hydroxyphenyl)butane (5a)
and (&)-3,4-bis(p-hydroxyphenyl)-hexane (5c) were
resolved, and absolute stereochemistry of the former was established as
(-)-(2R,3R) by correlation with (+)-(R)-2,3-bis(p-methoxyphenyl)but-1-en. The
(+) and (-) isomers of erythro-2,3-bis(p-hydroxyphenyl)pentane
(Sb) were synthesized from (-)- and
(+)-erythro-2,3-bis(p-methoxyphenyl)valeric acid,
respectively. (+)-erythro-2,3-Bis(p-hydroxyphenyl)pentane
(5b) was shown to have the (2R,3S) configuration, and
(+)-threo-(b)
the (2S,3S) configuration, by correlation with (-)-(8)-2,3-bis(p-methoxyphenyl)pent-1-ene. It follows that the configuration of
erythro-2,3-bis(p-methoxyphenyl)-valeric and the
corresponding-butyric acid is (+)-(2S,3R). Interaction of optically
active hexoestrol and its homologues with the oestrogen receptor active site is discussed in terms of
steroid stereochemistry.
Colouring matters of Australian plants. XV. Lomandrone, lomastilone, and lomazarin
Authors: Cooke RG , Robinson JB
Published: September 2010

The structure of lomandrone has been confirmed by synthesis of its methyl
ether. Two more new naphthoquinone pigments, lomastilone and lomazarin, have
been isolated from Lomandra hastilis
roots and structures have been assigned on the basis of spectrometric analysis.
Crystalline cobalt, zinc, manganese, and iron alkoxides of glycerol
Authors: Radoslovich EW , Raupach MR , Slade PG , Taylor RM
Published: September 2010

A series of crystalline
metal glycerolato complexes has been prepared. The
preparation of the cobalt, zinc, manganese, and iron complexes [(1 )-(4)] was
achieved by heating (above 110�) glycerol with metal acetates, carbonates,
oxalates, oxides, or hydroxides. The structure of (1) has been determined by
X-rays and contains Co-O-Co-O and Co-O-C-C-O rings. X-ray powder diffraction
and i.r. data are given for (1)-(4). These show (1)
and (2) to be isostructural and that (3) and (4) are variants of these. The
insolubility of (I), (2), (3), and (4) is in accord with their polymeric
nature.
Recalculation of the friction constant and transport coefficients of liquid argon from the Rice-Allnatt theory
Authors: Collings AF , Woolf LA
Published: September 2010

The linear trajectory
approximation of the ?soft? friction constant in the Rice-Allnatt
theory of transport has been computed with specific attention to the lower
limit of the integral. The results are significantly different from the Palyvos-Davis values for ζS
in the dense gas region but agree within 2% in the liquid region. The Rice- Allnatt expressions for the coefficients of shear viscosity
and thermal conductivity have been simplified and a correction of a numerical
error in the collisional contributions to momentum and heat transfer is made.
The coefficients D, η, and λ have been calculated for the corrected ζS and related expressions. No significant
change in D is obtained, but a worsening of agreement with experimental
viscosities and thermal conductivities occurs. Conversely, a better prediction
of the ratio mλ/kη is obtained. More recent
viscosity data for liquid argon indicate the theory is less satisfactory than
has previously been considered. These results suggest that any improvement of
this class of theory can only come through the use of a better representation
of the radial distribution function.
Correlation of PVT properties of homologous series with critical constants
Authors: Pandya MV , Williamson AG
Published: September 2010

A general equation based
upon a modified principle of corresponding states and the principle of
congruence is used to correlate the second virial coefficients of n-alkanes and
their mixtures with each other and with hydrogen. The same procedure is extended
to perfluoro-n-alkanes and alk-l-enes.
Radiation-induced reactions with cellulose. IX. Copolymerization with styrene using a pre-irradiation procedure and the effect of additives on the grafting reaction
Authors: Dilli S , Garnett JL
Published: September 2010

The results of a study of
grafting to pre-irradiated cellulose are presented using the monomers styrene,
vinyl acetate, and 2- and 4-vinylpyridines. The effect of pre-irradiation dose
has been examined over the range 1-10 Mrad in air at
dose rates of 0.114-1.16 Mrad/hr. Of a number of
additives included in the grafting solutions, small amounts (10-23%) of acridine
completely suppressed grafting, anthracene inhibited it, and the halobenzenes
produced a sensitization in the reaction.
Detritiation in 1,8-dimethylnaphthalene, acenaphthene, and perinaphthane
Authors: Opie MCA , Wright GJ , Vaughan J
Published: September 2010

The rates of detritiation of [2-T]-, [3-T]-, and [4-T]-1,8-dimethylnaphthalene
and the corresponding specifically labelled acenaphthenes and perinaphthanes have
been measured a t 30° in anhydrous trifluoroacetic acid. The order of ortho and para
reactivities is acenaphthene > perinaphthane > 1,8-dimethylnaphthalene; the
meta positions are much less reactive in the order acenaphthene > 1,8-dimethyl-
naphthalene > perinaphthane. This pattern of reactivity is discussed in terms of
steric and strain effects in the transition states.
Chlorine nuclear quadrupole resonance studies of K2IrCl6-K2PtCl6 solid solutions
Authors: Fergusson JE , Scaife DE
Published: September 2010

The cubic lattice
parameters for the solid solution system K2IrCl6- K2PtCl6
vary approximately linearly with composition from a0 = 9.765�0.001 Ǻ
for K2,IrCl6, to a0 = 9.748�0.001 Ǻ for K2PtCl6.
The 35Cl n.q.r, frequencies show shifts from the frequencies observed
in the pure compounds, these shifts being approximately linear with composition
at each of the temperatures 77�K, 201�K, and 298�K. The shifts in frequency on
going from 0-100% Pt are, for the chlorine atoms bonded to the iridium, +93
kHz, and for the chlorine atoms bonded to the platinum, +84 kHz. ��� The infrared stretching frequencies of the
MCl62- groups also show shifts which are approximately
linear with composition. The extrapolated shifts in going from 0-100% Pt are
+11 cm-1 and +4.5 cm-1 for the Pt-Cl and Ir-Cl stretching
frequencies, respectively. The n.q.r. and infrared results are best accounted
for by small changes in the M-Cl bond lengths within the MCl62-
group, with concurrent changes in a0, and possibly also in the
positional parameter u. Re-examination of the variation of magnetic susceptibility
with composition in the K2IrCl6-K2PtCl6
system is also reported, and reasons proposed for the form of this variation. ��� 35Cl n.q.r. frequencies are
reported for Cs2IrCl6.
Vibrational spectra of crystalline halomercurate(II) complexes
Authors: Hooper MA , James DW
Published: September 2010

The vibrational spectra of
crystalline halomercurate salts with anionic stoicheiometries HgX3-,
HgX42-, Hg2X5-, Hg3X82-
(where X = Cl, Br, I) have been studied. The cations Me4N+, Et4N+,
Ph4As+, and pyH+ were used as necessary. The effect of crystalline
symmetry and packing on the spectra of both anion and cation are discussed and
the spectra are used to deduce the most probable crystalline packing for salts
containing the Hg2X5- and Hg3X82-
species. The spectra of the cations Me4N+ and Et4N+
are assigned and discussed.
Ligand design and synthesis. I. 3-Amino-1-(8'-quinolyl)-1-thiapropane and related ligands
Authors: Black DSC , McLean IA
Published: September 2010

The chelating properties of
3-amino-I-(8?-quinolyl)-1-thiapropane (2) are discussed. The related ligands
1-(2?-hydroxyphenyl)-6-(8?- quinolyl)-5-thia-2-azapent-1-ene
(6), 1-(6?-bromo-2?-hydroxyphenyl)-5- (8?-quinolyl)-5-thia-2-azapent-1-ene
(7), 5-(2?-pyridyl)-1-(8?- quinolyl)-1-thia-4-azahex-4-ene
(8), and 5-[2?-(6?-acetylpyridyl)]-1- (8?-quinolyl)-1-thia-4-azahex-4-ene
(13), and some of their metal complexes are described. The iron(II) sexadentate
chelate (17) has been prepared by a metal template synthesis from the amine (2)
and glyoxal.
The effects of nitrous oxide and ethylene on the gas yields and gel formation from γ-irradiated polypropylene
Authors: Pinkerton DM
Published: September 2010

Isotactic and atactic
polypropylene have been y-irradiated in a vacuum, in nitrous oxide, and in
ethylene, and also in the presence of mixtures of these two gases. The y-irradiation
of the isotactic polypropylene in a vacuum gives a H2 yield which is
non-linear with dose, whereas the CH4 yield is linear with dose.
Yields of H2 and CH4 from atactic polypropylene obey a
linear relationship with the dose delivered. Both N2O and ethylene
depress the G(H2) obtained from vacuum irradiations of isotactic
polypropylene, the former due to electron scavenging and the latter to hydrogen
atom scavenging. The scavenger studies lead to G(e-) = 0.7�0.1, G(H)thermal
= 1.0�0.1, and G(H2)moleculer = 1.86�0.05. ��� Compared to vacuum irradiations, N2O
enhances, and ethylene suppresses completely, the crosslinking yield in
isotactic polypropylene. In equimolar mixtures of N2O and ethylene
the crosslinking yield is suppressed completely. It is suggested that N2O
enhances the crosslinking mechanism through an energy transfer and dehydrogenation
process and that ethylene interferes by radical scavenging. In mixtures, the
results are consistent with ethylene participating in the energy transfer reaction
in preference to the N2O and so inhibiting the additional
crosslinking that N2O causes through the dehydrogenation reaction. A
tentative reaction sequence is proposed.
Copper(II) complexes of aryl-aci-nitromethanes
Authors: Graddon DP , Harradine ND
Published: September 2010

The copper(II) complexes, CuL2, of aryl-aci-nitromethanes
(LH = RR?CNO2H; R? = H, R = C6H5, p-CH3C6H4,
or o-CH3C6H4; R = R? = C6H5)
have been examined. The magnetic and spectroscopic properties of the solids are
consistent with planar, four-coordinate chelate structures with weak
intermolecular interactions. In donor solvents six-coordinate adducts are
formed; CuL2(py)2(R
= C6H5) has been isolated and CuL2(DMSO)2
(R = C6H5) shown to occur in benzene-dimethyl sulphoxide
solutions; the free energy of formation of the dimethyl sulphoxide adduct is
comparable to that of base adducts of copper(II) β-diketone complexes.
Photoassociation due to electron transfer. Exciplex formation in non-polar solvent
Authors: McDonald RJ , Selinger BK
Published: September 2010

Exciplexes may be formed by
exciting either partner of a given electron donor-acceptor pair. As the
formation of such exciplexes is reversible, dissociation may lead to excitation
energy transfer. ��� The temperature dependence of fluorescence
excitation spectra has proved to be a powerful tool for exploring these
systems.
Thermodynamics of metal-ligand bond formation. III. Adducts of heterocyclic bases with Bis(N-nitroso-N-phenylhydroxylaminato)copper(II)
Authors: Graddon DP , Hsu CY
Published: September 2010

The copper(II) complex of
N-nitroso-N-phenylhydroxylamine (copper cupferrate) reacts with heterocyclic
bases in benzene solution to form 1 : 1-adducts. Enthalpies and entropies of
adduct formation with a range of bases have been determined by thermometric titration.
The results, which are similar to those obtained with copper(II) complexes of
β-diketones, reveal two isoequilibrium series for sterically hindered and
unhindered bases, and indicate that the effect of the steric hindrance is
probably to restrict rotation of the base molecule about the newly formed
metal-ligand bond.
Diterpenoids. XXX. The selenium dehydrogenation of agathic acid
Authors: Carman RM , Craig WJ
Published: September 2010

The results of an
examination of the selenium dehydrogenation of agathic
acid and its simple hydrogenation derivatives are reported. Dehydrogenation of
intermediate.: has enabled the results to be rationalized into a consistent
scheme. The dehydrogenation of methyl sandaracopimarate
was also examined at two temperatures.
The chemistry of 2,1-benzisothiazoles. IV. The preparation of 3-substituted 2,1-benzisothiazoles
Authors: Buckley RK , Davis M , Srivastava KSL
Published: September 2010

Eight 3-substituted 2,1-benzisothiazoles
have been prepared from 3- amino-2,1-benzisothiazole (2; R = NH2) by
diazotization and replacement of the diazonium group. Acylation of 3-amino-2,1-benzisothiazole
in the presence of base yielded N,N?-diacyl derivatives of the 3-imino
tautomer.
Carbonyl halides of the Group VII transition metals. I. Halocarbonyls and halocarbonyl anions of rhenium(I)
Authors: Colton R , Knapp JE
Published: September 2010

The rhenium(1)
halocarbonyls Re(CO)5X (X = Cl, Br, I) may be readily prepared by
refluxing a solution of the free hexahalorhenate(1V) acid in hydrohalic acid
with formic acid. Visible absorption spectral studies indicate that formation
of the halocarbonyls takes place following an initial reduction to
rhenium(111), but no halocarbonyls of this intermediate oxidation state were
isolated. The concentration of
rhenium, as well as the relative amounts of hydrohalic and formic acids in the
reaction mixture, are important factors for efficient production of the
halocarbonyls. If the halocarbonyls are refluxed in formic acid containing a decreased proportion of hydrohalic acid,
decarbonylation occurs giving the halocarbonyl anions [Re(CO)4X]2-
which can be isolated as their caesium salts or as the parent halocarbonyls
[Re(CO)4X]2. Continued refluxing of the formic acid
solution causes still further decarbonylation giving the halocarbonyl anions
[Re(CO)3X3]2- (X = Cl, Br) which may also be
isolated as their caesium salts.

Alternatively, evaporation to dryness of these solutions
without addition of cations gives the new rhenium(1) halocarbonyl aquo
complexes Re(CO)3(H2O)2X (X = Cl, Br). In the
case of the iodo system, decarbonylation did not proceed to the tricarbonyl
stage.
Acridone studies. VIII. Preparation and properties of the Monobromo-, Nitro-, Amino-, and Piperidino-10-methylacridones
Authors: Hodgeman DKC , Prager RH
Published: September 2010

The preparation and
spectral properties of the four monobromo-, nitro-, amino-, and piperidino-10-methylacridones
are described.
Metal template reactions. VII. Synthesis of macrocyclic quadridentate complexes of nickel(II), cobalt(II), and copper(II)
Authors: Black DSC , Kortt PW
Published: September 2010

The synthesis of N,N'-bis(2'-formyl-4'-nitrophenyl)-1,3-diaminopropane
is described. This dialdehyde (2) and the previously
described ethylene analogue (1) have been used in reactions of nickel(11),
cobalt(11), and copper(11) acetates and 1,2-diaminoethane, 1,3-diaminopropane,
1,3-diamino-2-methylpropane, 1,2-diamino-oyclohexane, and 1,2-diaminobenzene,
and these reactions have afforded a variety of metal complexes of ten macrocyclic
ligands (5)-(14). These ligands contain 14-, 15-, or 16-membered rings.
Activity coefficient assumptions in the determination of association constants. VI. Association of thallium(I) bromide from absorbance measurements
Authors: Chan CY , Panckhurst MH
Published: September 2010

Measurements are reported of the optical absorbance of aqueous solutions of
thallium(I) bromide in mixture with other electrolytes a t 25°. These measurements
are similar to those previously reported1 for thallium(I) chloride and are used in
conjunction with two different types of ionic activity coefficient expressions to
investigate association of thallium(I) bromide. Both types of expression give a
reasonable description of the experimental results but there is the same disagreement
with the analysis of solubility measurements found for thallium(1) chloride.
The synthesis of pseudoprotopine, an alkaloid from Zanthoxylum conspersipunctatum (Rutaceae)
Authors: Sotelo RM , Giacopello D
Published: September 2010

The protopine alkaloid isolated from Zanthozylurn conspersipunctatum Merr.
& Perry, has been synthesized confirming the assigned structure (1). The name of
pseudoprotopine is suggested for the natural base.
The synthesis and properties of some 7- and 12-Cycloaliphatic Beaz[a]anthracene derivatives
Authors: Vaughan GB , Vingiello FA
Published: September 2010

The effect of different alicyclic substituents on the course of an aromatic
cyclodehydration reaction was investigated by synthesizing a number of precursor
ketones. By studying their cyclization products, a competitive cleavage reaction
was observed and interpreted.
Synthesis and reactions of some pyrrolethiols
Authors: Harris RLN
Published: September 2010

A number of pyrrolethiols have been prepared by the alkaline hydrolysis
of the corresponding S-pyrrolylisothiouronium salts. Although generally too
reactive to be isolated unless stabilized by electron-withdrawing substituents
in the pyrrole ring, these compounds have proved
reliable intermediates and undergo the usual reactions of thiols, e.g. acylation, alkylation, oxidation, and addition to
acetylenes, isocyanates, and
isothiocyanates. Two relatively stable pyrrolethiols
have been fully characterized and spectral evidence indicates that they exist
in the thiol form.
Indolizines. II. A facile synthesis of 3-Alkoxycarbonyl-, 3-Cyano-, and 3-Carbamoyl-indolizines and its mechanism
Authors: Dainis I
Published: September 2010

Acylative cyclization of 1-benzyl-, 1-alkoxycarbonylmethyl-,
1-cyanomethyl-, and 1-oximinomethyl-2-methylpyridinium salts gives good yields
of 2,3-disubstituted, and 1-acyl-2,3-disubstituted, indolizines.
This general method provides a novel and convenient route to indolizines bearing those electronegative 3-substituents
which can be removed or modified, and hence offers considerable potential for
the synthesis of 1,2-disubstituted and 2-substituted indolizines.
With appropriately
2-substituted pyridinium salts this method also provides syntheses of 1-acetoxy-2,3-disubstituted
and other l,2,3-trisubstituted indolizines. Hydroxypyridines give acetoxyindolizines
in good yield. Product studies have shown
conclusively that acyl-and diacyl-methines are the
major intermediates in this reaction. Ethyl chloroformate
reacts selectively with indolizines to give good
yields of ethyl indolizine-3-carboxylates. These products and also
3-cyanoindolizines are readily characterized by reaction with acid formaldehyde
to give methylene-1,l'-diindolizines. N.m.r. data are reported
for a number of indolizines and pyridinium salts.
The acid-catalysed rearrangement of a 1,2-Diphenyl-2a,8b-dihydrocyclobuta-[a]naphthalene. A new synthesis of triarylethylenes
Authors: Collin PJ , Teitei T , Sasse WHF
Published: September 2010

Treatment of
4,8b-dimethyl-1,2-diphenyl-2a,8b-dihydrocyclobuta[a]naphthalene (4) with
trifluoroacetic acid gives the stereoisomeric
2-(1,4-dimethylnaphthyl)-stilbenes (5) and (6), the
structures of which have been proved by an independent synthesis. One of these stilbenes rearranges irreversibly under the influence of
trifluoroacetic acid to its stereoisomer; stereomodels
suggest that the less stable isomer has the structure (5). Mechanisms are
proposed for the rearrangement of (4) to (5) and for the direct conversion of
(4) into (6).
Claisen rearrangement of allyl imidates and thioimidates derived from lactams and thiolactams
Authors: Black DSC , Eastwood FW , Okraglik R , Poynton AJ
Published: September 2010

Allyl imidates
N=C(OCH2CH=CH2)CH2, derived from lactams,
rearrange on heating to yield the
corresponding C-allyl and N-dlyl lactams,I

NHCOCHCH2CH=CH2 and N(CH2CH=CH2)COCH2

while allyl thioimidates yield only the C-allyl thiolactams.
The C-allylation is postulated to occur through a
ketene acetal intermediate by way of a quasi-chair transition state. The yield
of 3-allylhexahydro-2H-azepin-2-one obtained in such a rearrangement is
significantly increased by the presence of 2-pyridone.
Studies on double acylation of aromatic hydrocarbons. XI. A total synthesis of 5,6-Dihydro-4H-benz[de]anthracene
Authors: Rahman A , Vuano BM , Rodriguez NM
Published: September 2010

Starting from ethyl
3-(1-naphthyl)propionate (1), the dibasic acid 4-(4-carboxy-ethyl-I-naphthyl)butyric
acid (3) was prepared, which served as a key compound for the synthesis of
5,6-dihydro-4H-benz[de]anthraoene (6) by a double
intramolecular cyclization. The monocyolization of
the dibasic acid (3) gave rise by a preferential six-membered ring closure,
to 3-(1-oxo-1,2,3,4-tetrahydro-9-phenanthryl)propionic
acid (7). A partial synthesis of
5,6-dihydro-4H-benz[de]anthracene (6), by succinoylation of perinaphthane
followed by usual synthetic steps, is reported as confirmatory evidence of the
identity of (6) obtained by double cyclization of the diacid. Some aspects of the
orientation of intramolecular acylation are
discussed.
Studies in the synthesis of furocoumarins. XIV. Synthesis of psoralene from 2-bromoresorcinol
Authors: Pardanani NH , Trivedi KN
Published: September 2010

A synthesis of psoralene and alkylpsoralenes
from 2-bromoresorcinol is described. Treatment of
2-iodomethyl-8-oxo-2,3-dihydro-8H-furo[2,3.h][l]benzopyran
with sodium and ethanol is shown to yield 2-methyl-8-oxo-8H-furo[2,3-h][1]- benzopyran rather than the corresponding dihydrofuran.
The structure of azralidoside
Authors: Rizvi SAI , Sultana T
Published: September 2010

A new glycoside, azralidoside, has been isolated from the flowers of Cassia nodosa
and characterized as 3-ethyl-23-methyl-22-β-rutinosyloxy)-5-pentacosanolide
on the basis of spectral and degradative studies.
The effect of water vapour on the behaviour of the oxygen electrode in molten nitrates
Authors: Fredericks M , Temple RB
Published: September 2010

Water vapour has been
deliberately introduced into an oxygen gas electrode in an equimolar NaXO3-KNO3
melt at 300�. When this is done the slope of the line obtained for ECe11
against log[O2-]Total changes from the 2.303RT/2F
obtained with dry oxygen to almost exactly 2.303RT/F. On discontinuing the
passage of water vapour into the melt, the cell reverts to its original
condition within 3 hr. These experimental results are discussed theoretically.
The results also yield a value of 3.2 x 10-2 for the equilibrium
constant of the reaction

O2 + H2O = 2OH-
The chemistry of pyrrolic compounds. XIX. Reactions of pyrrolic compounds with orthoformates
Authors: Clezy PS , Fookes CJR , Liepa AJ
Published: September 2010

A mixture of triethyl orthoformate and
trifluoroacetic acid has been developed as a means of formulating certain pyrroles and dipyrrylmethanes. The advantages and
disadvantages of the procedure are discussed. The use of p-toluenesulphonic acid with orthoformate converts pyrroles
into tripyrrylmethanes.
Dithiochelates of the biscyclopentadienylvanadium(IV) moiety. I. Biscyclopentadienylvanadium(IV) xanthates
Authors: Casey AT , Thackeray JR
Published: September 2010

The first xanthates of vanadium(1V) to be isolated have been prepared
in aqueous media from op2VClz and NaS2COR (R =
CH3, C2H5, i-C3H7, C4H9,
and C6H11).
The purple crystalline solids are monomeric 1 : 1 electrolytes in solution and
believed to be of the form

(see diagram in text)

Room temperature magnetic moments
are c.1.65 B.M. and the magnetic
susceptibility follows the Curie law. Infrared, electronic, and e.s.r. spectra
are reported.
Ionization current measurements in gases using an internal tritium β source
Authors: Cooper R , Mooring R
Published: September 2010

The β-particles from
tritium have been used as an energy source for the ionization of gaseous
xenon, argon, neon, and oxygen. The ion currents determined from an ionization
chamber study of T2-gas mixtures enable the energy required to form
an ion pair (W value) to be
calculated for these gases. A series of fluorocarbon gases have also been
studied and their W values determined
for the first time. Consideration of the energy
transfer (Jesse) effect limits the usefulness of this technique to gases of
ionization potential of less than 15.5 eV.
Photorearrangement of trans-1,1′:3,4-Diepoxy-1-methyl-2-tetralone, an α,β:α′,β′- diepoxyketone
Authors: Schneider DS , Eastwood FW
Published: September 2010

Irradiation of
trans-l,l':3,4-diepoxy-1-methyl-2-tetralone (1) with a medium-pressure mercury
lamp yielded 2,3-dihydroxy-1-naphthaldehyde (2), 2,4-dihydroxy-1-naphthaldehyde
(3), and 3-(2'-hydroxyphenyl)-4H-pyran-4-one(4).
The additivity of methyl groups in electrophilic substitution
Authors: Richards KE , Wilkinson AL , Wright GJ
Published: September 2010

The rates of detritiation at the ring positions in the
polymethylbenzenes have been obtained for exchange at 70�in
anhydrous trifluoroacetic acid. The first-order rate constants are analysed in
terms of the additivity principle, which is shown not to hold for this system;
derived partial rate factors, describing the effect of ortho,

meta, and para methyl groups on reactivity, decrease as the reactivity of
the ring site increases. Much better agreement between observed and calculated
results is obtained if the demand for stabilization made on the methyl groups
in the transition state is assumed proportional to the activation free energy.
This approach requires no more parameters than the additivity principle, but
corrections for ortho-meta and meta-para buttressed methyl groups can
give further improvement where required. The application
of this "demand-dependent free energy relationship" to other systems,
and the origin of the buttressing effects, are discussed.
Chemistry of the indoleninones. I. Derivatives of 2-chloroindoleninone (α-chloroisatin) on reaction with methanethiol, benzenethiol, and 1,2-ethanedithiol
Authors: Baker JT , Duke CC
Published: September 2010

The reactive 2-chloroindoleninone has been used to prepare a series of
2,2-and 3,3-dialkylthio- and diarylthio-indolinones,
2-phenylthioindoleninone, and 2-methylthioindoleninone,
the last named being a debromo analogue of a product
of hydrolysis and dehydrogenation of 6-bromo-2-methylthioindoxyl
sulphate, an absolute precursor to the major
constituent of the dye Tyrian Purple.
The Structure of the Degraded Hualtaco Gum
Authors: Samajpati S , Rao CN
Published: September 2010

Autohydrolysis of purified and fractionated hualtaco
gum yielded a degraded product. The degraded gum, fully methylated, gave on
hydrolysis 2,3,4-tri-O-methyl-L-rhamnose (2 eqniv.),
2,3,4,6-tetra-O-methyl-D-galactose (1
equiv.), 2,4,6-tri-O-methyl-D-galactose
(1 equiv.), and 2,4-di-O-methyl-D-galaotose
(6 eqniv.). The methyl aldobiouronic
acid was characterized as 6-O -(2,3,4-tri-O-methyl-D-

glucuronopyranosyl)-2,3,4-tri- O
-methyl-D-galactopanose. From the results of
periodate oxidation and Smith degradation studies carried out on the degraded
gum, a structure was assigned to its repeating unit.
A theoretical study of the 14N and 17O N.M.R. shifts in lanthanide complexes
Authors: Golding RM , Halton MP
Published: September 2010

The experimental 14N
and 17O n.m.r, results in a series of lanthanide complexes are
successfully interpreted from a second-order perturbation treatment of the
calculation of (S2), where bonding effects and spin-orbit coupling
mixing are incorporated. The isotropic hyperfine interaction constants are
shown to be negative for 14N and positive for 17O but
both independent of the particular lanthanide ion. We also confirm that the 4f
orbitals are not involved in direct bonding with the
ligands.
Spectra of dimers of anthracene and its derivatives. I. Sandwich dimers
Authors: Ferguson J , Mau AWH , Morris JM
Published: September 2010

Sandwich dimers are
obtained by photochemical cleavage of dianthracene
and related compounds in a rigid glass matrix at 77 K. Detailed studies of the
absorption spectra, fluorescence spectra, and fluorescence lifetimes of
symmetric dimers of anthracene and 9-substituted anthracenes (both molecules
the same) and dissimilar dimers (one molecule anthracene, the other 9- or 9,10-substituted
anthracene) have been made. Particular attention has been paid to these
properties during dissociation of the dimers as the glass is allowed to soften.
The fluorescence properties show a discontinuity during this dissociation. The
excimer emission maxima (lifetimes about 200 ns) move a little to higher energy
(lifetimes decrease to about 100 ns) then broad structure is observed in the
spectra and lifetimes drop to about 5 ns. The fluorescence spectra of the
dissimilar dimers are of the excimer type with lifetimes of about 100 ns. These
values do not appear to be compatible with existing theories of the excimer
state.
The stabilities of carbonium ions
Authors: Miller IJ
Published: September 2010

An empirical bond energy
scheme for carbonium ions is derived which gives good agreement with
experimental values for some primary, secondary, and tertiary ions. If the
chemical bonds are considered as polarizable, the bond energy scheme, and some
reactions of carbonium ions, can be rationalized solely from the application of
classical electrodynamics. As example it is deduced that dienylic ions are less
stable than cyclopentenylic ions and cyclohexenylic ions. It is also shown that
the activation energy for the cyclization of dienylic ions is largely composed
of electrostatic repulsion between the equally charged ends. While the results
are mainly applicable for the gas phase an approximate discussion of solvation
energies shows that, while all C-C bonds stabilize a carbonium ion centre to a
greater extent in the gas phase, a methyl will stabilize positive charge to a
greater extent than, say, an ethyl in aqueous solution if the positive charge is
less than 0.6e. That is, the Baker-Nathan order is predicted in solution if the
charge is delocalized. It is concluded that the concept of hyperconjugation is
unnecessary for a description of carbonium ions.
A study of the electron impact promoted fragmentation of promazine sulphoxide and promazine using specifically deuterated analogues
Authors: Solomon MD , Summons R , Pereira W , Duffield AM
Published: September 2010

The mass spectra of some
promazine sulphoxide derivatives have been examined. Specifically deuterated
analogues of promazine and promazine sulphoxide were prepared and their mass
spectra used to determine the specificity of the hydrogen transfer processes observed
in the unlabelled compounds.
An approach to the stereospecific synthesis of nordebromolaurinterol
Authors: Feutrill GI , Mirrington RN
Published: September 2010

The synthesis of
3-(2?-hydroxyphenyl)-2,3-dimethylcyclopent-ene (8) has been effected in six
steps from o-iodoanisole; a key step was the conversion of (7) into (8), each
being acid-sensitive, by demethylation with sodium thioethoxide in dimethyl-formamide.
��� The reactions of (8) and its acetate (22)
with several methylenating agents were examined, but no cyclopropane-containing
products were obtained.
A double pulse method of N.Q.R. detection
Authors: Doolan KR , Hacobian S
Published: September 2010

A method of n.q.r. detection is described in which pairs of radiofrequency
pulses from a super-regenerative oscillator excite and detect resonance. For large
enough intervals of time between successive pairs of pulses, the nuclear signal produced
by any pair decays well below noise level at the arrival of the next pair, so that the first
pulse of each pair does not detect n.q.r. The second pulse is then moved along the
nuclear induction signal, produced by the first pulse of each pair, to record its variation
as a function of time. A method is given for the evaluation of the apparent spin-spin
relaxation time from measurements taken using a sample of p-dichlorobenzene at 23°C.
Studies of oxidations by fenton's reagent using redox titrations. IV. Oxidation of ethanol and t-butyl alcohol
Authors: Ingles DL
Published: September 2010

The oxidation of ethanol by
Fenton's reagent was studied to confirm the validity of the redox titration
procedure. A quantitative analysis of oxidation products during the complete
oxidation of ethanol and its consecutive oxidation products is presented.

� The
oxidation of t-butyl alcohol was studied under a number of different conditions
and yields of acetone and the dimer, 2,5- dimethylhexane-2,5-diol, were
obtained. The effects of oxygen, copper salts, and chloride and bromide ions on
this oxidation were studied. ��� The ratio of reaction rates of ethanol and
t-butyl alcohol with the free hydroxyl radical was determined.
Electron impact studies. LXXVII. The question of scrambling in arylpyridine molecular ions
Authors: Bowie JH
Published: September 2010

The loss of a phenyl
radical from the molecular ion of 2,4,6- triphenylpyridine is a slow process
which occurs mainly from the 2- position with a minimum of scrambling of the
pyridine carbon atoms or migration of the phenyl groups. The spectra of 2H,
13C, and F labelled derivatives demonstrate that no phenyl/pyridine
carbon scrambling occurs during this process, that fluorine scrambling does not
occur between the phenyl residues, but that considerable hydrogen scrambling
precedes or accompanies fragmentation. The loss of HCN from the [M- Ph.]+
ion of 2,4,6-triphenylpyridine occurs in a specific manner, showing that the
original pyridine carbon atoms retain their positional identity during this
elimination.
Annelated furans. XII. Fries rearrangement of isocreosol esters
Authors: Chan HTJ , Elix JA
Published: September 2010

The Fries reaction of
2-methoxy-5-methylphenyl butyrate (5) in the presence of titanium tetrachloride
gave only the para rearrangement product, 4-hydroxy-5-methoxy-2-methylphenyl
propyl ketone (6). Irradiation of the ester (5) gave the ortho rearrangement product,
2- hydroxy-3-methoxy-6-methylphenyl propyl ketone (7), in addition to (6),
isocreosol, and 2-hydroxy-4-methylphenyl propyl ketone (8). The photorearrangement
of 3-nitropropionate esters of isocreosol and related phenols did not proceed
satisfactorily as the 3-nitropropionyl group appeared unstable under these
conditions. However, the photo- Fries rearrangement of the corresponding
3-chloropropionate esters proceeded normally with the formation of o- and
p-hydroxyphenyl 2- chloroethyl ketones, and in addition the substituted
o-hydroxyphenyl vinyl ketones, generated by elimination of hydrogen chloride
from the corresponding ortho rearrangement product.
The possible formation of iron(V) and cobalt(V) in molten sodium nitrite
Authors: Temple TB , Thickett GW
Published: September 2010

Chemical and magnetic
evidence is presented to support the view that the complex anions FeVO43-
and CoVO43- are formed when molten sodium
nitrite is electrolysed between electrodes of the appropriate metal or when its
salts are added to molten nitrite solutions of Na2O2. The
reflectance spectrum of CoVO43- has been
recorded between 11000 and 26000 cm-1.
Copper(II)-promoted solvolyses of nickel(II) complexes. I. N,N-Dialkyldithiocarbamates
Authors: Fee WW , McElholum DE , McPherson AJ , Rundle DL
Published: September 2010

The kinetics of copper(II)-promoted
solvolyses of bis(N,N- dibutyldithiocarbamato)nickel(II)
in dimethyl sulphoxide (dmso), N,N- dimethylacetamide
(dma), acetone, and chloroform, and bis(N,N- dicyclohexyldithiocarbamato)nickel(II) in dmso and dma have been examined.
Although the reaction stoichiometry differs in chloroform compared with the
other solvents, in all media the two-term rate law

����������������� -d[Ni(dtc)2]/dt = (k1+k2[Cu2+])[Ni(dtc)2]

is obeyed. However, in the
absence of added sodium and nickel ions, experiments in dmso
at low [Cu2+]O, indicate a negligible contribution from
the k1 path. Results are discussed in the light of a mechanism involving
primary dissociative (k1) and associative (k2) steps.
Although the ratios k2/k1 indicate overall importance for the
associative pathways of reaction in the low dielectric media cf. dmso and dma, the k1
term also appears as a significant contributor to the reaction of the dibutyldithiocarbamate complex in the former solvents.
Reactions of trifluoromethyl radicals. II. Hydrogen abstraction from monochlorosilane
Authors: Arthur NL , Harman BR
Published: September 2010

Hydrogen atom abstraction
from SiH3Cl by CF3 radicals

����������������� CF3 + SiH3Cl
→ CF3H+SiH2Cl������������������� (1)

has been studied in the
temperature range 69-168�. The rate constant, based on Ayscough's
value of 1013.36 cm3 mol-1 s-1 for
the recombination of CF3 radicals, is given by (k1 in cm3
mol-1 s-1, E in kJ mol-1):

������������������ logk1 =
(12.38�0.06)-(25.72�0.41)/2.303RT At 400 K, the rate constant
for CF3 + SiH3Cl is greater than the average value
reported for CF3+SiHCl3 by a factor of 3.6. This is due
to a difference in A factors since the activation energies are equal within
experimental error.
Synthesis of some tricyclic amines - Hexahydro-1H-indenoazepines and a Hexahydro-1H-benzo-quinoline and -isoquinoline
Authors: Evans DD , Weale J , Weyell DJ
Published: September 2010

2,3,4,4a,5,6-Hexahydro-1H-indeno[7,1-cd]azepine
(6), 2,3,3a,4,5,6- hexahydro-1H-benzo[de]quinoline (10),
2,3,3a,4,5,6-hexahydro-1H- benz[de]isoquinoline (12), isolated as their
hydrochlorides, and 2,3,4,4a,5,6-hexahydro-1H-indeno[7,1-bc]azepine (8) have been
prepared by lithium aluminium hydride reduction of the corresponding lactams
which were synthesized from the appropriate tricyclic ketones by Beckmann
rearrangement or Schmidt reaction. The base (8) was also synthesized from
1,2,3,4-tetrahydronaphthalene-1,8-dimethanol (15).
Small Gaussian basis sets for molecular calculations. II. Effect of basis set size on the calculated wavefunction and a useful GTO basis set
Authors: Burden FR , Hart BT
Published: September 2010

A quantitative assessment
of the importance of basis set variation at the minimal basis level of accuracy
has been carried out. A number of basis sets, using Gaussian lobe functions,
were tested by calculating the energy and one-electron properties for a number
of molecules and the results used to select an optimum sized accurate basis
set. This basis set consisted of a five-component 1s-Gaussian type orbital
(GTO), a three-component 2s-GTO and a three-component 2p-GTO for each first row
atom, and a three-component 1s-GTO for hydrogen. The accuracy of wave functions
calculated with the minimal basis sets was very sensitive to changes in the
2p-GTO. ��� A Gaussian lobe basis set of optimum size
for use with large molecules is given. The results of testing this set by
calculating several one-electron properties for ten molecules, together with
confidence limits, are also presented.