bluuebunny/crossref_metadata_2025 huggingface dataset:
Coordination compounds of manganese(II) with Tetrahydro-1,4-thiazin-3-one and Thiazolidine-2-thione
Authors: Preti C , Tosi G
Published: September 2010

Synthetic and
characterization studies of manganese(11) complexes with
tetrahydro-l,4-thiazin-3-one (tht) and
thiazolidine-2-thione (ttz) are reported. The methods
used for the characterization of the compounds include elementary analyses,
molar conductances, magnetic moments and electronic and
infrared spectroscopy. Assignments for the metal-ligand modes have also been
made; the tht derivatives are coordinated through the
oxygen atom, while the ttz derivatives are
nitrogen-bonded in all the complexes. By use of infrared spectroscopy it has
been possible distinguish whether or not the polyanions
present in these derivatives are coordinated to the metal ion or are present as
free ions.The wavelengths of the
principal absorption peaks have been accounted for quantitatively in terms of
the crystal field theory. The values of B and C obtained are significantly
lower than the corresponding value for the free gaseous ion.
A contribution to the theory of cementation (metal displacement) reactions
Authors: Power GP , Ritchie IM
Published: September 2010

In this paper, cementation
(metal displacement) reactions are discussed in terms of Evans diagrams, i.e.
diagrams constructed by the superposition of cathodic and anodic polarization
curves. The conditions under which the rate of a cementation reaction will be
controlled by cation diffusion to the reacting metal surface or some chemical
step at the surface are explored. It is found that for the case in which the
effective cathodic and anodic areas are approximately equal, the cementation is
likely to be diffusion-controlled when its two component oxidation-reduction
reactions have standard electrodepotentials which differ by
more than 0.36 V. The ratio of cathodic to anodic area is also found to be important
in determining the reaction mechanism. The presence of an oxide film on the
metal is shown to be another factor which influences the reaction mechanism.
Evans diagrams are used to discuss the composition of the product layer formed
during a cementation reaction.
Coordination compounds of Hg22+: The crystal structure of Bis(acridine)dimercury(I) perchlorate
Authors: Taylor D
Published: September 2010

Crystals of bis(acridine)dimercury(1)
perchlorate, [Hg2(C13H9N)2] (ClO4)2
are monoclinic, a = 10.629(1), b = 16.841(2), c = 7.142(1) �, β = 99.06(2)�, space group I2/m
with Z = 2 dimeric formula units. The structure was solved from
three-dimensional diffractometer X-ray data(1427 independent
reflections), block-diagonal least-squares refinement of all atoms, including hydrogens,
converging at R = 0.028. The mercury dimer, Hg-Hg 295177(5)�, is coordinated in
the axial positions by the acridine molecules, Hg-N
2.150(5) �, the cation having C2h symmetry.There are also two long
contacts from each mercury atom to oxygen atoms of the perchlorate ions, Hg-0
2.958(6) �. Evidence for a metal-ligand steric interaction is presented.
Crystal structure and electronic spectrum for Bis(O-ethylxanthato)pyridinezinc(II)
Authors: Raston CL , White AH , Winter G
Published: September 2010

The crystal structure of
the title compound [Zn(C5H5N)(CS2OEt)2]
has been determined from X-ray diffractometer data at 295 K and refined by
full-matrix least squares to a residual of 0.061 for 1100 'observed'
reflections. Crystals are monoclinic A2/a,
a = 14.001(5), b = 8.911(2),

c = 13.731(6) � ,β = 104.80(3)�, Z =
4. The molecule lies on a twofold axis passing through the N-coordinated pyridine ring. The zinc atom is coordinated by the
pyridine [Zn-N, 2.03(l) �] and a pair of symmetry related asymmetric
ethylxanthate chelates [Zn-S, 2.748(3), 2.294(3)&.The electronic spectrum of
the complex has been studied in a variety of basic solvents and the spectra rationalized
in terms of the observed structure.
Thermodynamics of metal-ligand bond formation. XX. Reaction of tertiary phosphines with mercury(II) halides
Authors: Gallagher MJ , Graddon DP , Sheikh AR
Published: September 2010

Tertiary phosphines form highly stable 1 : 1 and 2 : 1 adducts with
mercury(11) halides in benzene solution. In the series of phosphines
(alkyl),PPh3-n enthalpies of formation are determined by inductive
effects and give a linear relationship with Taft constants, ∑σ*. The
cyclic phosphine 1,2,5-triphenylphosphole is a much weaker base towards the
mercury(11) halides. While ethane-1,2- diylbis(dipheny1phosphine)
behaves only as a chelate, methylenebis(dipheny1phosphine)
can behave both as a chelate and as a bridging ligand and
propane-1,3-diylbis(dipheny1phosphine) only as a bridging ligand. The
unsaturated diphosphines (2)- and
(E)-ethene-l,2-diylbis(dipheny1phosphine) both form 1 : 1 adducts with
mercury(11) halides in benzene solution in which the phosphines
are unidentate. Enthalpy data are reported for the
formation of all these adducts.
Chromium(II) reduction of the μ-Amido-di-μ-hydroxo-bis[triamminecobalt(III)] complex in aqueous perchlorate solution
Authors: Edwards JD
Published: September 2010

The kinetics of the
reduction of [(NH3)3Co,μ(NH2,0H,0H),Co(NH3)3]3+
by chromium(11) ion in aqueous perchlorate solution is reported. The results
are interpreted in terms of a rapid pre-equilibrium involving hydrogen-ion
catalysed hydroxo bridge cleavage, followed by rate determining
inner-sphere reduction. A deprotonated aqua ligand is the bridge for electron
transfer.
Spectra of zinc tetrabenzporphyrin in n-octane
Authors: Fielding PE , Mau AWH
Published: September 2010

A detailed spectroscopic
study of zinc tetrabenzporphyrin in n-octane reveals
the following: (i) the relative magnitude
of solute-solvent interaction in the ground and excited states increases in the
order T1 < S0 < S1 < S2. (ii) The potential energy
surface minima of the ground and excited states are very similar within the
framework of the Franck-Condon principle. (iii) The absence of any
hot-band emission from the Q band (S1) and any emission from the Soret band (S2) indicates that significant
amounts of energy degrade to the lowest vibrational level of S1. (iv) An earlier report on
monomer phosphorescence is mainly due to aggregation. Selective narrow-band
excitation is shown to be a useful technique to unravel complex spectra of
porphyrins in Shpolskii-type matrices. Accurate
measurements can be made of the energies for electronic transitions between the
ground and excited states of molecules isolated in the various sites of the
host matrix. The intensity ratios for electronic and vibronic
bands can also be determined.
The chemistry of the indoleninones. III. Reactions of 2-(Methylthio)indoleninones with diazomethane
Authors: Baker JT , Duke CC
Published: September 2010

The reactions of
2-(methy1thio)indoleninone [2-(methylthio)-3H-indol-3-one] and its 4-bromo and
6-bromo derivatives with diazomethane lead to the appropriate
2-(methylthio)spiro[3H-indole-3,2'- oxirans] and
3-methoxy-2-(methy1thio)quinolines in relative yields dependent upon the steric
in- fluence of bromine when in the 4-position. P.m.r. studies on the
2-(methylthio)spiro[3H-indole-3,2'-oxirans] reveal a marked solvent depen-
dence on the chemical shift values of the non-equivalent protons of the methylene
group in the oxiran ring.
Purine studies. XIX. Rodential metabolism of 2-(6',8',9'-Trimethylpurin-2'-ylthio)propionamide and related purines
Authors: Brown DJ , Stephanson LG
Published: September 2010

The metabolic oxidation of
three purines, which increase the antibiotic activity
of phleomycin in vitro, has been
investigated in mice. 2-(6',8',9'-Trimethylpurin-2'-ylthio)acetamide
(lb) gave 46% unchanged amplifier and 26% of the corresponding sulphoxide (1c); the homologous propionamide
(1f) gave only 20% unchanged material, 6% of the corresponding sulphoxide (1g), 30% of a highly unusual metabolite (1h)
formed by hydroxylation of the 8'-methyl group, and two unidentified products;
and 6,8,9-trimethyl-2-(piperidin-1'-yl)purine (1k)
gave but 4% unchanged material, a little 6,8,9-trimethylpurin-2-one, and c. 45%
of an intractable product. 2-(6',9'-Dimethylpurin-2'-y1thio)acetamide
(la) was appreciably less metabolized to its 8-oxo derivative (2; R = SCH2CONH2)
in rats than in mice. Unambiguous syntheses for radioactively labelled
amplifiers, metabolites and potential metabolites are described.
Visible spectral data for pseudo-tetrahedral metal complexes - C2v d1 compounds
Authors: Coutts RSP
Published: September 2010

The visible spectral data
available for a range of bis(cyclopentadienyl)titanium(111)
derivatives (d1 systems) are discussed in relation to the proposed
one-electron energy level schemes suggested for molecules of C2v symmetry.
Fluorine magnetic resonance studies. II. Long-range fluorine-fluorine coupling in 2,β,β-Trifluorostyrenes and related compounds
Authors: Burgess DA , Rae ID , Smith LK , Snell JD
Published: September 2010

Five β,β-difluorostyrenes
and a 1-difluoromethyleneindan bearing a fluorine substituent on the aromatic
ring ortho to the side chain have been prepared from the corresponding carbonyl
compounds. Sodium chlorodifluoroacetate and tris(dimethylamino)phosphine in triglyme
at 160� is most effective in converting hindered ketones into β,β-difluorostyrenes. The 19F N.M.R.
spectra for solutions of these compounds in carbon tetrachloride and
dimethylformamide have been analysed. Fluorine-fluorine coupling over five bonds
ranges from 4 Hz in the flexible 2, β,β -trifluorostyrene to 69 Hz in the rigid indan.
Variations in the spectra produced by structural and solvent changes are
explained in terms of conformational effects. The ultraviolet absorption
spectra of the β,β difluorostyrenes
are similar to those of the styrenes,
Resonance and solvent effects on absorption spectra of 2-nitroaniline derivatives
Authors: Yokoyama T
Published: September 2010

Spectral data for
N-methyl-2-nitroaniline correlate well with those for
N,N-dimethyl-2-nitroaniline in non-hydrogen-bonding, hydrogen-bond-accepting
and amphiprotic alcoholic solvents. This same pattern
has been reported for N-methyl-2-nitro-p-toluidine. These results indicate that
these N-methyl compounds have no hydrogen bonds with any of the solvents
studied and intramolecular hydrogen bonding predominates. In the N.M.R. spectra
of such amines, long-range coupling between the H5 (ring) and N-H protons is
not necessarily evidence for intramolecular hydrogen bonding.� +M substituents at the 4-position increase
the twist of the dimethylamino and 2-nitro groups and
enhance the C1 → C2 transition, an effect which follows the order of +M
abilities of the 4-substituents.
Zirconium(IV) carboxylates
Authors: Paul RC , Baidya OB , Kumar RC , Kapoor R
Published: September 2010

Zirconium(IV) carboxylates, Zr(OOCR)4
where R = Me, Et, CH2Cl2 CHCl2 and CCl3,
have been prepared by the reaction of zirconium(IV) chloride and carboxylic
acids. The compounds have been characterized by elementary analyses,
thermogravimetry and infrared spectral data. The compounds are non-electrolytes
in nitrobenzene and probably have polymeric structures.
2,7-Bis(dimethylamino)anthracene and 2,2',7,7'-Tetrakis(dimethylamino)-9,9'-bianthracene
Authors: Kissane PJ , Johns SR , Willing RI , Sasse WHF
Published: September 2010

The action of chloranil in
boiling methanol on 2,7-bis(dimethylamino)-9,l0-dihydroanthracene
(5)produces 2,2',7,7'-tetrakis(dimethylamino)-9,9'-bianthracene
(6b); dehydrogenation of (5) with palladium-on-carbon in toluene gives
2,7-bis(dimethy1amino)anthracene (1).
Organometallic compounds in synthesis. VIII. Carbon-13 nuclear magnetic resonance spectroscopic study of tricarbonylcyclohexadienyliron salts
Authors: Birch AJ , Westerman PW , Pearson AJ
Published: September 2010

The carbon-13 N.M.R.
spectra of eleven substituted tricarbonylcyclohexadienyliron
salts (1) have been determined and individual resonances assigned. Substituent
effects have been deduced and compared with corresponding effects in cyclohexadienyl cations. The structures of the tricarbonylcyclohexadienyliron salts are discussed with
reference to chemical shift data. The proportions of irreversible nucleophilic
attack at the terminal positions in the unsymmetrical 2-substituted salts are
compared with the observed chemical shifts at these carbon atoms.
A synthesis of tetracyclo[5,3,1,12,6,04,9]dodecane (iceane)
Authors: Hamon DPG , Taylor GF
Published: September 2010

A description is given of
the chemistry which led to the synthesis of the title compound (1). Key
intermediate compounds in this synthetic route were tricyclo[5,3,1,04,9]undec-5-en-2-one
(13), tricyclo[5,3,1,04,9]undec-2-en-endo-6-ylmethanol (36) and the exo and endo isomers of chloroiceane (42) and
(44). Compound (42) must have a chlorine atom in the prow position of one of
the three rings in boat configurations.
Benzylidene derivatives of mannitol
Authors: Brecknell DJ , Carman RM , Kibby JJ
Published: September 2010

Further work is reported on
the known 1,3(R):4,6(R)-di-O- and 1,3(R):2,5:4,6(R)-tri-O-benzylidene derivatives of D-mannitol.
New 1,3(R)-mono-O-,1,2(R):4,6(R)-di-O-, 1,2(S):4,6(R)-di-O-, 1,2(R):5,6(R)-di-O-,
1,2(S):5,6(S)-di-O-,
1,2(S):5,6(R)-di-O-and
1,3(R):2,5(S)-di-O-benzylidene
derivatives are reported.
Cyclic analogues of β-adrenergic blocking agents cis- and trans-3-Amino-6-bromochroman-4-ols
Authors: Lap BV , Williams LR
Published: September 2010

N-(6-Bromo-4-oxochroman-3-yl)acetamide (4; R = Ac) can be reduced by sodium borohydride
to the cis-N-(6-bromo-4-hydroxychroman-3-yl)acetamide (6) and this can be hydrolysed to give the cis-3-amino-6-bromochroman-4-ol (7) or
converted into the corresponding trans-3-amino-6-bromo- chroman-4-ol (12) by
chlorination with inversion followed by hydrolysis of the chloride (8) to the
alcohol with retention of configuration. The assignment of configuration of the
3,4-substituted chromans is based on the value of the
coupling constants between the H3 proton and the methylene protons on C2 and is
supported by an observed difference in the rate of hydrolysis of the two
N-(6-bromo-4-chlorochroman-3-yl)acetamides.
A synthesis of some model kynurenine peptides
Authors: Rivett DE , Stewart FHC
Published: September 2010

Protected peptides
containing glycine and DL-2-o-nitrophenacylglycine
have been synthesized and then converted into a series of model DL-kynurenine peptides by catalytic hydrogenation with
generation of the kynurenyl residue and concomitant removal of protecting
groups.
The use of chiral N.M.R. shift reagents in a study of the stereochemistry of bianthrones
Authors: Cameron DW , Edmonds JS , Feutrill GI , Hoy AE
Published: September 2010

The use of chiral N.M.R. shift reagents in the identification of diastereomers has been extended to asymmetric bianthrones. Studies on model systems have reinforced the
stereochemical assignment of meso- and (�)-emodin bianthrone.
Iminyl radicals in gas-phase synthesis. III. Synthesis of a terminally unsaturated nitrile
Authors: Crow WD , McNab H , Philip JM
Published: September 2010

The previously reported
generation of α- and ω-cyanoalkyl radicals
has been substantially improved by the use of the oxime esters of cyclopentanone and cyclohexanone instead of the azines. Fragmentationof the α-cyanoalkyl radicals to acrylonitrile
is still observed, but the efficiency of alkylation of the residue is
considerably enhanced. A synthetic device is described for intercepting the
first-formedω-cyanoalkyl
radicals with the formation of terminally unsaturated nitriles. This involves
pyrolysis of the 5,6-dihydro-4H-l,2-oxazin-6-ones. The preparation and
pyrolysis of 4,4a,5,6-tetrahydro-3H-naphth[l,2-c][1,2]oxazin-3-one to
2-(but-3-eny1)benzonitrile is described.
Temperature-dependence of 35Cl N.Q.R. in sodium chloroacetate
Authors: Chandramani R , Devaraj N , Sastry VSS , Ramakrishna J
Published: September 2010

N.q.r. in sodium chloroacetate
has been investigated at temperatures from 77 K to room temperature (c.300 K).
A single line has been observed throughout this temperature range. Torsional
frequencies of the molecule have been calculated in the above temperature range
from Bayer's theory. Also the temperature coefficient of the torsional
frequencies has been calculated by Brown's method.
Thermodynamics of metal-ligand bond formation. XXIII. Lewis acidity of mercury(II) thiocyanate
Authors: Farhangi Y , Graddon DP
Published: September 2010

Thermodynamic data are
reported for the reaction of Lewis bases with mercury(11) thiocyanate in
acetonitrile solution. Pyridine, 4-methylpyridine and tetrahydrothiophen
form 1 : 1 adducts with adduct formation constants and enthalpies of formation
comparable to those with mercury(11) iodide. 1,l0-Phenanthroline,
2,2'-bipyridine and N,N,N',N?-tetramethylethane-1,2-diamine
form chelate 1 : 1 adducts, but with enthalpies of formation little larger than
that with pyridine. The phosphines, PPh3
and Pbu3, form 1 : 1 and 1 : 2 adducts of much greater stability,
though the enthalpies of formation of these adducts are also similar to that
with pyridine; Hg(SCN)2PBu3 is dimeric in dilute
solution.
The Di-π-methane rearrangement of 1,3,3-Triaryl-3-methoxyprop-1-enes
Authors: Brophy JJ
Published: September 2010

A series of
1,3,3-triaryl-3-methoxyprop-1-enes has been synthesized to study the effects of
substituents on the migratory aptitudes of aryl groups in the di- π-methane rearrangement
leading to methoxy cyclopropanes. In most cases little specificity was found.
3-Aryl-3-methoxy-l,3-diphenylpropenes formed both
c-2-aryl-r-1-methoxy-1,t-3-diphenylcyclopropane and
I-aryl-r-1-methoxy-t-2,c-3-di- phenylcyclopropane while, with one exception,
1-aryl-3-methoxy-3,3-diphenylprop-1-ene yielded t-2-aryl-r-1-methoxy-l,c-3-diphenylcyclopropane.
The rate of rearrangement of 1-aryl-3-methoxy- 3,3-diphenylprop-1-enes, with
the exception of the p-methoxyphenyl compound (4d), which does not react, has
been found to be almost invariant of the substituent in the aryl group.
Synthesis of octadeuterocubane and variously deuterated cubane analogues
Authors: Della EW , Patney HK
Published: September 2010

The syntheses of
deuterocubane, 1,4-dideuterocubane, 1,2,3,4,6,7- hexadeuterocubane,
and octa-deuterocubane of high isotopic purity are
described. Several new derivatives of cubane were characterized, and an
improved procedure for the decarboxylation of carboxylic acids via their
t-butyl peroxy esters is suggested.
Photochemistry of cyclododecanone
Authors: Burchill PJ , Kelso AG , Power AJ
Published: September 2010

Quantitative measurements
of the photolytic reactions of cyclododecanone gave quantum yields of reaction
and of intersystem crossing as 0.56 and 0.88 respectively, and a triplet
lifetime of 1.7 x 10-7 s. Cyclobutanol formation accounts for most
of the reaction with only a low yield of the Norrish
II cleavage product; this contrasts markedly with the opposite behaviour of
acyclic ketones of similar size. The results may be explained by the apparent
restriction of rotation in cyclododecanone molecules.
The role of non-bonding electron pairs in the asymmetric coordination environments of 1,1-dithiolate complexes
Authors: Hoskins BF , Pannan CD
Published: September 2010

Various forms of asymmetry
in the lengths of the bond between the central atom and sulphur, found in
differing coordination environments of 1,1-dithiolate compounds involving main
group atoms, have been successfully rationalized by considering both the valence
shell electron pair repulsion theory and the effect of the restricted ligand
bite distance.
Temperature dependence of diffusion in 3-methylpentane/methylcyclohexane mixtures above their glass transition temperatures
Authors: Smith GJ , Claridge RFC
Published: September 2010

The temperature dependences
of the phosphorescence decay from the triplet state of naphthalene embedded in
3- methylpentane/methylcyclohexane mixtures of different compositions in the
presence and absence of oxygen have been determined and are presented as
Arrhenius plots. In the presence of oxygen, the slopes of these plots above the
glass transition temperature depend on the composition of the mixture. It is
shown that the effect of solvent composition in this temperature region can be
explained by interactions between the solvent molecules which affect the
activation energy of diffusion of the oxygen which is quenching the triplet
state of naphthalene. ��� In the absence of oxygen, the effect of
solvent mixture composition is small, and it is suggested that the deactivation
of the triplet state is affected by steric constraints imposed by the
surrounding molecules.
Radical reactions of p-Nitrobenzylidene dichloride with lithium 2-nitropropan-2-ide. Consecutive SRN1 and ERC1 reactions
Authors: Freeman DJ , Norris RK
Published: September 2010

The reaction of
p-nitrobenzylidene dichloride with the lithium salt of 2-nitropropane gives
initially the monosubstituted compound, p- NO2C6H4CH(Cl)CMe2NO2, by a radical-anion
radical chain, SRN1 process. This compound then undergoes a
radical-anion radical chain elimination reaction giving the styrene, p-NO2C6H4CH=CMe2,
and the dimer of 2- nitropropane, Me2C(NO2)CMe2NO2.
This latter reaction, which is designated ?ERC1?, also occurs in
competition with an E2 reaction in the reaction of the methanesulphonate, p-NO2C6H4CH(OMs)CMe2NO2,
with the 2- nitropropan-2-ide ion giving the above styrene and the enol
methanesulphonate, p-NO2C6H4C(OMs)=CMe2,
respectively. Catalytic, inhibition, and substituent effects are used to
confirm the operation of these radical processes.
4,5-Di-O-methylhiascic acid, a new tridepside from the lichens Parmelia pseudofatiscens and Parmelia horrescens
Authors: Elix JA , Engkaninan U
Published: September 2010

The tridepside
4,5-di-O-methylhiascic acid (8) has been isolated from the lichen Parmelia
pseudofatiscens. The structure of this compound followed from the spectroscopic
data and has been confirmed by total synthesis. This new tridepside was also
shown to occur in the lichen Parmelia horrescens.
Preparation of 3-Oxochroman and derivatives of 4'-Methoxyflav-2-ene (3-Cyano, 3-Formyl, and 3-Hydroxymethyl)
Authors: Clark-Lewis JW , Ilsley AH , McGarry EJ
Published: September 2010

3-Oxochroman was prepared
by a known route from chrom-3-en-3-carboxylic acid, and 3-ethoxy-carbonyliminochroman
and other intermediates were characterized. 3-Formyl-4?-methoxyflav-2-eneand
3-cyano-4?-methoxyflav- 2-ene were prepared in an attempt to obtain 4?-methoxyflav-2-en-3-
carboxylic acid for conversion into 4?-methoxy-3-oxoflavan. However, the
aldehyde proved resistant to oxidation, and the nitrile resisted hydrolysis, so
that this route to 3-oxoflavans appeared unpromising. Reduction of 3-formyl-4?-methoxyflav-2-ene
gave the acid-sensitive allylic alcohol, and 3-formyl-4?-methoxyflav-2-ene
itself underwent acid-catalysed rearrangement to a mixture of cis- and
trans-2-hydroxy- 3-(4-methoxybenzoyl)chroman.
Alkylations of Tricarbonylcyclohexadienyliron Salts with Mixed Alkylcuprate Reagents
Authors: Pearson AJ
Published: September 2010

A study of the reaction
between mixed alkylcuprate reagents [Li(R1R2Cu)] with tricarbonylcyclohexadienylironsalts (1) has shown that,
when R2 = SPh, alkylation of (1) may be
achieved in moderate to good yields for R1 = Pri,
Bu and But. Only minor yields are obtained for R1 = Me
and CH2=CH, the main reaction being thiophenoxylation, but for these
substituents alkylation is achieved with the dialkylcuprate.
The regioselectivity of the reaction has been studied for a number of cuprate reagents.
Tautomerism of pyrazolidine-3,5-diones. II. Infrared spectra
Authors: Woodruff M , Polya JB
Published: September 2010

The tautomerism of a number
of N1- and N1,N2-substituted monotriazolylpyrazolidine-3,5-diones
and their phenyl analogues has been examined by infrared spectroscopy. The
diketo tautomer is the predominant form, both in the solid state and in
chloroform solution. Monosodium salts of 4,4-dialkyl-1-triazolylpyrazolidinediones
show unusual absorption which indicates strong hydrogen bonding in the
compounds; a three-centre hydogen bond is proposed to explain the observed spectra.
Methyleneketenes and methylenecarbenes. VIII. Pyrolysis of methoxyacetylene
Authors: Baxter GJ , Brown RFC , Eastwood FW , Harrington KJ
Published: September 2010

LFlash vacuum pyrolysis
(600°) of 5-methoxymethylene-2,2-dimethyl-1,3-dioxan-4,6-dione (1) gives
either methoxymethyleneketene (3) or decomposition
products considered to be formed from methoxyacetylene. Pyrolysis of
methoxyacetylene gives a complex mixture of products, including methylketene,
ketene, formaldehyde, acetylene, ethylene and ethane. A convenient procedure
for the preparation of methylketene and its dimer is also described.
Surface distribution functions-virial expansions
Authors: Spurling TH , Lane JE
Published: September 2010

The grand partition
function for the system of a gas interacting with a solid has been expanded as
a virial series. Singlet and radial distribution functions derived from this
have been calculated for the krypton/graphite interface and the results
compared with those of recent Monte Carlo calculations. The implication of the
results for the interpretation of experiments is discussed.
Studies on tellurium-carbon bonded compounds. II. The crystal structure of [Heptane-3,5-dionato(2 - )]tellurium(II) ('1,1′-Dimethylacetylacetone tellurium(II)')
Authors: Dewan JC , Silver J
Published: September 2010

The structure of the title
compound has been determined by the heavy- atom method from 973 reflections,
measured with a diffractometer, and refined by full-matrix least-squares
methods to R 0.030. Crystals are monoclinic, space group P21, a =
8.69(1), b = 4.86(1), c = 10.14(2) Ǻ, β = 98.7(1)�, Z = 2. In the
discrete molecules of the complex a tellurium(II) atom is bonded to one
bivalent heptane-3,5-dione ligand through the α-carbon atoms [Te-C
2.184(6), 2.206(7) Ǻ; C-Te-C 89.7(3)�], forming a heterocyclic ring of
chair conformation with the methyl substituents both in equatorial positions.
The molecules are arranged in a zig-zag polymeric
manner about the 21 axes at x = 0 and z = 0. All hydrogen atoms have
been located.
Mass spectral studies of 3,5-Diamino-1,2,4-thiadiazoles
Authors: Joshua CP , Rajasekharan KN
Published: September 2010

The mass spectra and
fragmentation mechanisms of some 5-alkyl(or aryl)amino-3-amino-, 5-amino-3-
arylamino-, 3,5-bis(arylamino)-, 4- aryl-3-arylamino-5-imino-4,5-dihydro-, and
3-alkyl(or aryl)amino-4- aryl-5-arylimino-4,5-dihydro-1,2,4-thiadiazoles and
those of a 3-amino- 4-aryl-5-imino-4,5-dihydro-1,2,4-thiadiazole are discussed.
The study, based on the behaviour of isomers under electron impact, attempts to
evaluate the usefulness of mass spectra in structure determination of variously
substituted 3,5-diamino-1,2,4-thiadiazoles.
The chemistry of pyrrolic compounds. XXXV. Further observations on the chemistry of Spirographis porphyrin and its isomer: the oxidation offormylporphyrins
Authors: Clezy PS , Fookes CJR
Published: September 2010

Evidence is presented which
indicates that a mixture of hydriodic acid, acetic acid and air achieves the
oxidation of formylporphyrins through the agency of peroxyacetic acid. The
mechanism of the reaction is discussed. The oxidation of Spirographis porphyrin
and its isomer are described and the product of these oxidations related to a methoxycarbonyldeuteroporphyrin of known structure.
Improvements are recorded for the synthesis of Spirographis porphyrin and
related compounds.
t-Butyldimethylsilyl ethers of sucrose
Authors: Franke F , Guthrie RD
Published: September 2010

The usefulness of the
t-butyldimethylsilyl group as a blocking group in carbohydrate chemistry has
been demonstrated and its selectivity towards primary hydroxyl groups, in the
absence of imidazole, shown by preparation of derivatives of methyl α-D-glucopyranoside
and sucrose. Methyl α-D-gluco-pyranoside was converted into methyl 6-O-t- butyldimethylsilyl-a-D-glucopyranoside
in almost quantitative yield, and sucrose to 6,1?,6?-tri-O-t-butyldimethylsilylsucrose
in good yield. In the presence of excess sucrose, a mixture of 6?-O-t-
butyldimethylsilyl-, 6,6?-di-O-t-butyldimethylsilyl- and 6,1?,6?-tri-O- t-butyldimethylsilyl-sucroses
was formed.
Electron impact studies. CXI. +E Spectra from negative ions. The retro-Diels-Alder process
Authors: Bowie JH , Ho AC
Published: September 2010

Abundant peaks produced by
retro-Diels-Alder cleavages are observed in the dissociative + E spectrum of a
negative ion, whenever such peaks are seen in the corresponding positive-ion
spectrum of that compound.
Photolysis of the 3,4-Epoxy-2-methyl-1-phenylbutan-1-ones and stereochemical assignment of the 3,4-Epoxy-2-methyl-1-phenylbutan-1-ols and 2-Methyl-1-phenylbut-3-en-1-ols
Authors: Coxon JM , Hii GSC
Published: September 2010

The stereochemistry of the
diastereoisomeric 2-methyl-1-phenylbut-3-en- 1-ols,
3,4-epoxy-2-methyl-1-phenylbutan-1-ols and 3,4-epoxy-2-methyl-1- phenylbutan-1-ones
have been established. In the photolysis of the 3,4- epoxy-2-methyl-1-phenylbutan-1-ones
the steric interaction between the C2-methyl and the C1-substituents determines
the stereochemistry of cyclization of the initially produced orthogonal
1,4-biradical intermediates.
The isomerization of ammonium cyanates. II. The kinetics of isomerization of ammonium and alkylammonium cyanates in dimethyl sulphoxide-water mixtures
Authors: Hall KJ , Watts DW
Published: September 2010

The kinetics of the
isomerizations of ammonium, methylammonium and ethylammonium cyanates to urea,
methylurea and ethylurea have been studied in aqueous dimethyl sulphoxide over
the range 0-100% dimethyl sulphoxide. Side reactions occur at all solvent compositions
and urea formation accounts for only between 65% and 90% of products. The side
reaction in water produces carbonate and in dimethyl sulphoxide biuret or
alkyl-substituted biurets. The proportion of each of these products in solvent
mixtures has not been determined.
The adsorption of hydrogen and oxygen on magnesium oxide: The effect of γ-irradiation
Authors: Breakspere RJ , Hassan LAR
Published: September 2010

The adsorption of hydrogen
and oxygen on magnesium oxide surfaces with and without the influence of
continuous γ-irradiation has been investigated. The temperature range for
hydrogen was 294-773 K, and for oxygen 294-973 K. In the absence of radiation
little adsorption of oxygen was detected below 573 K, but above this
temperature an activated process requiring an Ea of 60.6�5.0 kJ mol-1
was obtained. At all temperatures, continuous γ-irradiation enhanced the
adsorption, and a mechanism involving (e-|□-)s
defect centres has been proposed. Hydrogen adsorption was detected at all
temperatures in the absence of radiation and an enhancement of the uptake was
noted during radiation at all temperatures above 294 K. ��� The Gads for oxygen decreased
with increasing temperature whilst that for hydrogen increased with
temperature. A mechanism for this marked difference has been proposed.
The structure and stereochemistry of Edulan I and II and the stereochemistry of the 2,5,5,8a-Tetramethyl-3,4,4a,5,6,7,8,8a-octahydro-2H-1-benzopyrans
Authors: Whitfield FB , Stanley G
Published: September 2010

Edulan I and 11, two
important trace components of the juice of passionfruit Passiflora
edulis (Sims), were shown by micro-reaction g.l.c., by micro-spectrometry (m.s.,
N.M.R., i.r. and u.v.) and by com- parison with synthetic products to be the epimeric 2,5,5,8a-
tetramethyl-3,5,6,8a-tetrahydro-2H-1-benzopyrans (8a) and (8b). The relative
configurations of these isomers were established by their con- version into the
stereoisomeric 2,5,5,8a-tetramethyl-3,4,4a,5,6,7,8,8a- octahydro-2H-1-benzopyrans
(6a,b) and (6c,d) respectively. The evidence leading to the assignment of the
relative stereochemistry to the tetramethyloctahydrobenzopyrans
is presented.
Nitrones and oxaziridines. XVII. Photorearrangement of 3-Oxo-1-pyrroline 1-Oxides: A new route to Azetidin-2-ones
Authors: Black DSC , Boscacci AB
Published: September 2010

Several 3-0x0-1-pyrroline
I-oxides (1) undergo photorearrangement to the isomeric acyl azetidinones (3)
and/or oxazinones (4) in ratios depending on the nature of their
2-substituents. The azetidinones can be isolated pure in moderate yield from
reaction mixtures. In the case of 3-oxo-2-phenyl-l- pyrroline 1-oxide (la), the
isomeric oxaziridine (2a) is established as an intermediate in the
photorearrangement.
The hydrogenolysis of 1,8-cineole
Authors: Hugel HM , Jackson WR , Kachel CD , Rae ID
Published: September 2010

Reaction of 1,8-cineole with
hydrogen over supported platinum and palladium catalysts gives mixtures of cis-
and trans-p-menthanes. p- Cymene is also produced from reactions at higher
temperatures over palladium on pumice. Studies of reactions of potential
intermediates and of the reaction of 1,8-cineole with deuterium have led to a
proposed mechanism for the reaction.
Studies of Australian soft corals. I. A new cembrenoid diterpene from a Sarcophyton species
Authors: Coll JC , Hawes GB , Liyanage N , Oberhansli W , Wells RJ
Published: September 2010

A new cembrenoid diterpene
is reported from a Sarcophyton sp. of soft coral. It is a dehydro derivative of
the reported compound epoxynephthenol (3; R = H) which was isolated from a
Nephthea sp.1 Its structure was deduced from spectroscopic evidence
and confirmed by X- ray crystallography.
Amino oximes from p-Menth-1-ene, Limonene and α-Pinene
Authors: Carman RM , Mathew PC , Saraswathi GN , Singaram B , Verghese J
Published: September 2010

Substituted α-amino
oximes in the menthane and pinane series show interesting configurational and
conformational effects. A further example of a boat conformer is described.
Halogenated terpenoids. XV. An unsaturated tribromide from the bromination of α-pinene
Authors: Carman RM , Walker GJ
Published: September 2010

Bromination of
endo-2,endo-6-dibromobornane, obtained by bromination of α-pinene, yields unsaturated
2,3-endo-6-tribromoborn-2-ene (4).
Structural and spectral studies of halogeno complexes of rhodium(III)
Authors: Fergusson JE , Sherlock RR
Published: September 2010

Halogeno complexes of
rhodium(III) of the type A2 [RhCl5H2O], A3
[RhCl6],H2O and A3 [Rh2X9]
(X = Cl, Br, A = alkali metal, ammonium and
alkylammonium cations) have been prepared and investigated structurally by
X-ray powder photography, and by infrared and visible spectroscopy. The
relationship between the various preparative procedures has been determined.
Factors such as acidity and type of cation are important. Structural and
spectroscopic studies have revealed trends which, in some cases, can be related
to the influence of the cations on the halogenorhodate(III) anions in the solid
state, and, in other cases, to the ionic/covalent nature of the metal-halogen
bond.
The preparation of Tricyclo[4,2,1,02,5]nona-3,7-dienes by cycloadditions onto 3,4-disubstituted cyclobutenes. Specificities in the Diels-Alder reaction
Authors: Warrener RN , Anderson CM , McCay IW , Paddon-Row MN
Published: September 2010

The reaction between
cis-3,4-dichlorocyclobutene and 2,5-dimethyl-3,4- diphenylcyclopenta-2,4-dienone
forms a mixture of exo,anti (28) and endo,anti adducts (27) with the former predominating. At
higher temperatures the endo,anti adduct (27)
undergoes smooth decarbonylation to form
cis-7,8-dicldoro-2,5-dimethyl-3,4-diphenylbicyclo[4,2,0]octa-
2,4-diene. The stereochemistry of each adduct was determined by a combination
of spectral (especially p.m.r.) techniques and
chemical trans-formations. Intramolecular nucleophilic displacements and
electrophilically induced cyclizations have been instrumental in determining
stereochemical relationships. Similar cycloadditions involving
1,2,3,4-tetrachloro-5,5-dimethoxycyclopenta-1,3-diene and
1,4-dimethyl-2,3-diphenylcyclopenta-1,3-diene as the diene components and
cis-3,4-dichlorocyclobutene or dimethyl tricyclo[4,2,2,02,5]deca- 3,7,9-triene-7,8-dicarboxylate (10) as dienophiles
have been studied and the stereoselectivities determined. A combination of
steric and secondary orbital effects have been proposed to account for the
observed stereospecificities1. A PMO-based treatment is used to account for the
perispecificity of (10) and related alicyclic polyenes.
Nitrones and oxaziridines. XIX. Formation of β-Iminoalkylsulphonic acids by reaction of 1-Pyrroline 1-Oxides with sulphenes
Authors: Black DSC , Davis VC
Published: September 2010

The reactions of
2-unsubstituted 1-pyrroline 1-oxides with sulphene and phenylsulphene
(generated by the action of triethylamine on methane- and
phenylmethane-sulphonyl chloride respectively) afford (1-pyrrolin- 2-yl)methanesulphonic
acids, presumably via an intermediate cycloadduct. These iminosulphonic acids
can be hydrogenated to the related (1-pyrrolidin-2-yl)methanesulphonic acids.
The vibrational analysis of the 274-nm system of benzonitrile: A reinterpretation
Authors: Thistlethwaite PJ
Published: September 2010

Some aspects of the
vibrational analysis of the 274-nm system of benzonitrile have been
reconsidered in the light of revised i.r.-Raman data.
Four new upper-state frequencies have been identified and the four prominent
sequence intervals explained, and a number of other prominent features of the
spectrum accounted for.
Tritium exchange studies on metal oxide colloidal dispersions
Authors: Yates DE , Grieser F , Cooper R , Healy TW
Published: September 2010

The tritium exchange
technique has been used to detemine the maximum number of surface protons at
the oxide-water interface for oxide colloids including silicas, TiO2
(rutile) and the iron oxides goethite, hematite and amorphous iron oxide. The
effects of heat treatment, crystal structure and exchange conditions are
considered and tritium exchange values for the number of surface protons are
compared with values calculated from crystal structures.
Thiazolo[5,4-d]pyrimidine derivatives as amplifiers of phleomycin against Escherichia coli
Authors: Brown DJ , Dunlap WC , Grigg GW , Kelly J
Published: September 2010

The acetylation of
5-amino-6-methylpyrimidine-2,4-dithione (1; R = H) followed by cyclo-dehydration
gave 2,7-dimethylthiazolo[5,4-d] pyrimidine-5-thione (2; R = Me) which
underwent S-alkylation by methyl iodide, 2-chloroacetamide, etc, to afford the
corresponding 5-alkylthio derivatives (4a-c). Treatment of the same substrate
with carbon disulphide provided 7-methyl-thiazolo[5,4-d]pyrimidine-2,5-dithione
(6) and thence the corresponding 2,5-bisalkylthio derivatives (4d-g). Similar
reactions with 5-amino-6-mercapto-2-methylpyrimidine-4- thione(5; R1
= Me, R2 = SH, R3 = H) gave 7-alkylthio-2,5- dimethylthiazolo[5,4-d]pyrimidines (4h-p) and 2,7-bis-alkylthio-5-
methylthiazolo[5,4-d]pyrimidines [(4q) and (4r)]. Two
2-alkylthio-7- methoxythiazolo-[5,4-d]pyrimidines,
(4s) and (4t), were made by similar methods. ��� The foregoing compounds were tested in
vitro as amplifiers of phleomycin against E. coli. Some of the more soluble
compounds showed activities comparable with those of the best purine amplifiers
previously tested.
Chlorosulphonation of Some N-Phenyl-N'-pyridylureas
Authors: Badami NV , Cremlyn RJW , Swinbourne FJ
Published: September 2010

Chlorosulphonation of
N-phenyl-N?-2-pyridylurea (1; X = O) and the corresponding thiourea (1 ; X = S)
gave the 2?,4?-disulphonyl chloride (2; X = O, Y = Z = SO2Cl) and
the 4?-sulphonyl chloride (2; X = S, Z = H, Y = SO2Cl) respectively.
The sulphonyl chlorides were converted into the corresponding hydrazides,
hydrazones and azides. The additional ortho-sulphonation occurring with the
urea (1; X = O) is explained in terms of neighbouring group participation, and
dichlorosulphonation was confirmed by the N.M.R. spectrum of the acetone
disulphonohydrazone (3). In agreement with this theory, chlorosulphonation of
N-phenyl-N?- 4-pyridylurea (6) gave the 4?-sulphonyl chloride (7).
Oxidation of alkoxyphenols. XX. Ring cleavage and lactone formation in the oxidation of a Biphenyl-2,2'-diol by lead tetraacetate
Authors: Hewgill FR , Hewitt DG , Howie GB , Spencer WL
Published: September 2010

Two products in the lead
tetraacetate oxidation of 3,3?-di-t-butyl- 5,5?-dimethoxybiphenyl-2,2?-diol have
been shown to be (E)-7-t-butyl-5-
methoxy-3-[(E)-2?-methoxy-5?,5?-dimethyl-4?-oxohex-2?- enylidenelbenzofuran-2(3H)-one
(1) and its (Z,Z) isomer (3). Treatment of these with base causes rearrangement
to (E)-8-t-butyl-2-(3?,3?- dimethyl-2?-oxobutylidene)-6-methoxy-2H-1-benzopyran-4-carboxylic
acid (13). Further treatment with base produces pinacolone and 8-t-butyl-6- methoxy-2-oxo-2H-1-benzopyran-4-carboxylic
acid (14). The latter has been synthesized from 2-t-butyl-4-methoxyphenol via
7-t-butyl-5- methoxy-2,3-dihydrobenzofuran-2,3-dione (15).
Fluorescence quenching of excited state donor-acceptor pairs in surfactant micelles during a pH titration
Authors: Selinger BK
Published: September 2010

The fluorescence quenching
of acceptors by amines can be used for a pH titration of amines in surfactant
micelles. Alkane-linked donor- acceptor pairs are used.
Picosecond fluorescence spectroscopy with a streak camera
Authors: Fleming GR , Morris JM , Robinson HW
Published: September 2010

Streak cameras have enabled
kinetic data in the picosecond time regime to be obtained from single laser
shots. Digitization of the streaked image with an optical multichannel analyser
results in accurate fluorescent decay curves from which accurate fluorescence
lifetimes may be calculated, and in which non-exponential decays are readily
detected. This paper describes the characteristics of the picosecond laser
system at the University of Melbourne. For excitation, a Nd3+ :
glass mode-locked laser, Pockels cell pulse selector and various harmonic
generators are used; a streak camera/OMA system linked directly to a computer
is used to detect fluorescence.
An analysis of N.M.R. shifts in lanthanide complexes
Authors: Bergen HA , Golding RM
Published: September 2010

A method is developed to
analyse a range of N.M.R. shifts in lanthanide complexes and to estimate the
relative contact and pseudocontact contributions to the N.M.R. shifts for a
specific N.M.R. nucleus in the lanthanide complexes.
Deuterium exchange in water-methanol systems: Calculation of equilibrium constants
Authors: Fenby DV
Published: September 2010

Equilibrium constants for a
number of water-alcohol deuterium exchange reactions in the gas phase are
calculated from harmonic frequencies of CH3OH, CH3OD, CD3OH
and CD3OD obtained from recent infrared studies. These are combined
with vapour-pressure isotope effects to give equilibrium constants for the same
reactions in the liquid phase. Calculated equilibrium constants agree well with
most published experimental values.
Excited state acid-base reactions in micelles
Authors: Selinger BK , Weller A
Published: September 2010

The excited acid-base
reactions of 1-naphthol and pyren-1-amine have been studied in sodium dodecyl
sulphate surfactant micelles. These molecules which show complete equilibration
for excited state reactions in water show only partial equilibration in micelles
(2-naphthol goes from partial equilibration to complete lack of reaction). It
is believed that this is a micellar viscosity effect.
Isomerizations akin to the Dimroth rearrangement. III. The conversion of simple s-Triazolo[4,3-a]pyrimidines into their [1,5-a] Isomers
Authors: Brown DJ , Nagamatsu T
Published: September 2010

The treatment of
2-hydrazinopyrimidines (1) with acylating agents under appropriate conditions
is used to prepare s-triazolo[4,3-a]pyrimidine (6a) and its derivatives bearing
alkyl or aryl groups at the 3-, 5-, 6- , or 7-position. These compounds
rearrange in acid or alkali to give the corresponding s-triazolo[1,5-a]pyrimidines
(7). Rates for such isomerizations in alkali increase steeply in the range pH
10-12.5; in acid, they reach maxima at pH values corresponding approximately to
the pKa of each substance (in the range pH 1.5-2.5) and fall off on
both sides. Rearrangement of the parent heterocycle (6a) is slowed
significantly by each added 3-, 6-, and 7-alkyl group and slowed profoundly by
a 5-alkyl group: for example, 3,5,7-trimethyltriazolo[4,3-a]pyrimidine
rearranges 2500 times more slowly than the unsubstituted heterocycle at pH
11.3. The isomeric systems (6) and (7) are distinguished easily by their
tabulated u.v. and N.M.R. spectra.
New metabolites from the brown alga Cystophora torulosa
Authors: Gregson RP , Kazlauskas R , Murphy PT , Wells RJ
Published: September 2010

The lipid-soluble extract
of the brown alga Cystophora torulosa
has yielded a complex mixture of polyketide-derived alkenyl resorcinols and a
phloroglucinol, together with two straight chain polyenes. Two polyprenyl
chromans were also isolated in low yield.
Colouring matters of the Aphidoidea. XLIII. Crystal structure of the aphid pigment 'Quinone A'
Authors: Cameron DW , Hall SR , Raston CL , White AH
Published: September 2010

The crystal structure of
the quinone A, C15H14O6, derived from protoaphin-fb, has been determined by single-crystal X-ray
diffraction at 295 K and refined by least squares to a residual of 0.051 for
758 ?observed? reflections. Crystals are monoclinic, P21, a 5.239(4),
b 16.551(9), c 7.920(8) Ǻ, β 108.92(6)�, Z 2. The structure
determination confirms that proposed chemically, including the chirality of all
asymmetric centres in the molecule.
Reassignment of the 13C N.M.R. parameters of the 2-Phenylbicyclo[2,2,1]-hept-2-yl cation
Authors: Coxon JM , Steel PJ , Coddington JM , Rae ID , Jones AJ
Published: September 2010

Three of the seven carbon
resonances, namely C5, C6 and C7, in the 13C N.M.R. spectrum of the
2-phenylbicyclo[2,2,1]hept-2-yl cation skeleton have been reassigned by
consideration of the fine structure of the off- resonance decoupled spectrum,
and comparison with the spectra of 2- aryl-1,7,7-trimethylbicyclo[2,2,1]hept-2-yl
cations and the 3-deutero- 2-phenylbicyclo[2,2,1]hept-2-yl cation.
An ab initio molecular orbital study of the structure and properties of propadienone (methyleneketene)
Authors: Radom L
Published: September 2010

Ab initio molecular orbital
theory with minimal (STO-3G) and split- valence (4-31G) basis sets has been
used to obtain fully optimized structures for propadienone, allene, butatriene,
carbon dioxide, ketene and vinylidene. Propadienone is predicted to be a planar
molecule with C2V symmetry. The systematic deficiencies of the
STO-3G and 4-31G basis sets have been taken into account in deriving a complete
ro structure for propadienone. A striking feature of this structure
is the HCH angle (117.°) which is about 5° smaller than the corresponding
angle (122.3°) in ketene. An estimate (125 kJ mol-1) of the heat of
formation of propadienone is reported. The alternating dipole moment magnitudes
in the series H2CO, H2CCO and H2CCCO are
explained in terms of orbital interactions. Propadienone is predicted to be considerably
(about 135 kJ mol-1) more stable than vinylidene+carbon
monoxide but slightly (about 10-20 kJ mol-1) less stable than acetylene+carbon monoxide.
Upper critical solution temperatures of hydrocarbon + fluorocarbon mixtures
Authors: Hicks CP , Hurle RL , Toczylkin LS , Young CL
Published: September 2010

Values of the interaction
parameter ξ have been calculated from upper critical solution temperature data
by use of the van der Waals one- fluid model for a range of hydrocarbon+fluorocarbon
mixtures. The values obtained are compared with values calculated from
gas-liquid critical temperatures and mixed second virial coefficients where
experimental data on these properties are available. The overall agreement
between calculated from these properties is only fair but there is reasonable
agreement between ξ calculated from gas-liquid critical temperatures and
upper critical solution temperatures for mixtures of quasi-spherical molecules.
��� Experimental upper critical solution
temperatures are reported for 26 systems which have not been studied
previously. Gas-liquid critical temperatures of four systems are reported.