bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of mixed Gaussian lobe basis sets used for molecular calculations
Authors: Burden FR , Hart BT
Published: September 2010

Mixed Gaussian basis sets
of double zeta accuracy have been previously used to allow excellent
approximations to the energy and one-electron properties for molecular systems
to be calculated with a considerable economy in computational labour. Here we
show that these mixed basis sets also allow the calculation of accurate ESCA
binding energies using either the ?sudden? or ?adiabatic? approximations. The
basis sets are not recommended for the calculation of molecular geometries. ��� We have also tested some smaller mixed
basis sets and find quite large variations in the calculated one-electron
expectation values compared with those calculated using double zeta accuracy
mixed basis sets.
Vibrational spectra of metal-nitro complexes. III. The Tetranitro-platinate(II) and -palladate(II) ions
Authors: James DW , Nolan MJ
Published: September 2010

The vibrational spectra
have been obtained of salts having the general formula M2[M?(NO2)4]
where M is Na+, K+, Rb+, Cs+, Ag+
and M? is PtII or PdII. In solution the spectra were best
assigned to a D4h point group (tetranormal arrangement of NO2
groups). In the solid state factor group splitting was evident but the number
of bands observed was fewer than predicted. Where the structure was not known
approximate assignment was made by analogy with known structures. The spectra
indicate that π- bonding between metal and nitrogen is more pronounced for
the complexes of platinum(II).
Carbonyl nitrosyl halide complexes of molybdenum and tungsten. II. Triarylphosphine and arsine complexes of tungsten
Authors: Colton R , Commons CJ
Published: September 2010

Triphenylphosphine and triphenylarsine
derivatives of W(CO)4(NO)X (X = Cl, Br, I) have been prepared. These
compounds have the form mer- W(CO)3(NO)LX, cis-W(CO)2(NO)L2X,
and trans-W(CO)2(NO)(PPh3)2X. A trans complex
with triphenylarsine could not be prepared. Further substitution with either
ligand was not achieved. In addition, the tri(ortho-, meta-, and
para-)tolylphosphine and arsine complexes of W(CO)4(NO)I have been
isolated. Their nuclear magnetic resonance spectra indicate interaction between
neighbouring ligands in some cases, and suggest that possible rotation about
the metal-phosphorus and arsenic bonds may occur in these compounds.
Carbonyl nitrosyl halide complexes of molybdenum and tungsten. III. Bis(diphenylarsino)methane and Bis(diphenylphosphino)methane complexes of tungsten
Authors: Colton R , Commons CJ
Published: September 2010

Reaction of the potentially
bidentate ligand bis(diphenylarsino)methane (dam) with W(CO)4(NO)X
yields the complexes mer-W(CO)3(NO)(dam)X
and cis-W(CO)2(NO)(dam)2X in which the arsine ligand is
monodentate, and the novel complex [W(CO)2(NO)X]2(dam),
which is believed to contain both dam and halide bridges. ��� However, bis(diphenylphosphino)methane(dpm) forms cis- W(CO)2(NO)(dpm)X
and W(CO)(NO)(dpm)2X. The latter complex
contains both monodentate and bidentate dpm. ��� Nuclear magnetic resonance spectroscopy and
infrared spectroscopy have proved valuable in the elucidation of the structures
and properties of these compounds.
The homogeneous catalysed isomerization of 2-allylphenol and of (Z)-2-propenylphenol in the presence of a palladium catalyst
Authors: Davies NR , DiMichiel AD
Published: September 2010

The isomerization of
2-allylphenol (ap) in the presence of
bis(benzonitrile)-dichloropalladium(II) displays kinetics which differ in
certain respects from the normal isomerization of olefins catalysed
homogeneously by transition metal complexes. The most unusual feature is that
the rate increases continuously so long as a detectable concentration of ap remains. The behaviour is believed to be due to a
concentration of active catalyst which increases with time and with
concentration of the product, 2-propenylphenol (pp). The participation of the
phenolic hydroxyl group, resulting in chelation of pp to palladium is
considered to be responsible for the difference in behaviour between ap and, for example, allylbenzene. The isomerization of
(Z)-pp also displays unusual characteristics which are explained within the
framework of this hypothesis.
Hydroxyphenylazo-1,2,4-triazoles
Authors: Polya JB , Woodruff M
Published: September 2010

Azo dyes have been prepared
by coupling phenols with diazotized C- amino-1,2,4-triazole and
p-aminophenyl-1,2,4-triazoles. Spectroscopic proofs of structure establish
preferential para-coupling. The dyes exist in the azo form without evidence for
quinone hydrazone tautomers. Spectroscopic evidence and chelation not involving
the phenolic hydroxyl group suggest trans-configuration.
Schiff base equilibria. VIII. Aqueous equilibria between salicylaldehyde and aliphatic diamines
Authors: Green RW , Alexander PW , Sleet RJ
Published: September 2010

Equilibria between
salicylaldehyde and three aliphatic diamines, ethylenediamine, trimethylenediamine,
and 1,3-diaminopropan-2-ol, have been measured in aqueous solution containing a
large excess of diamine to suppress hydrolysis. Equilibrium constants are
reported for the formation and acid-base reactions of the
mono-salicylideneimines formed from the three diamines. It is demonstrated that
there are no conditions under which detectable concentrations of bis- salicylideneimines
exist in aqueous solution.
Complex nickel nitrites. I. Complexes of N-substituted Propane-1,3-diamines
Authors: Green RW , Bell B
Published: September 2010

Complex nickel(II)
nitrites, NiLn(NO2)2, can be prepared in good
yield by the reaction of amines with K4Ni(NO2)6.
Bonding of the NO2 group depends on the nature of the amine.
Paramagnetic, octahedral complexes of propane-1,3-diamine (pn)
and some of its N-alkyl derivatives were: pn, n = 2,
dinitro; N-methyl derivative, n = 2, dinitrito; N-ethyl, n = 2, dinitrito;
N,N-dimethyl, n = 1, dinitrito with bidentate nitrito groups. Corresponding
thiocyanate complexes were all NiL2(NCS)2. Homopiperazine
gave diamagnetic, square-planar complexes, NiL22+, for
all anions examined.
Kinetics of oxidation of nitrite by aqueous chlorine
Authors: Pendlebury JN , Smith RH
Published: September 2010

The kinetics of oxidation
of nitrite to nitrate by chlorine in aqueous acid solution (pH 0-1) have been
studied using a spectrophotometric stopped flow technique. The rate law is

���������������� -d[Cl2]a/dt =([Cl2][NO2-]/Ka[Cl-]2)(f+g[HNO2])

where [Cl2]a
= [Cl2]+[Cl3-] and where Ka is the
ionization constant for nitrous acid. At 298.2 K and ionic strength 2.75M, f =
60.8�0.5 mol2 l-2 s-1 and g = (2.35�0.05)x105
mol l-1 s-1: the associated activation energies are 68�3
and 44�2 kJ mol-1 respectively. A mechanism is proposed involving
the reversible initial step:

�������������������������� NO2-+Cl2
↔ NO2Cl+Cl-

with the NO2Cl
undergoing two parallel subsequent reactions, one a unimolecular decomposition
and the other an attack by HNO2 upon NO2Cl. ��� Oxidation of nitrite by the three halogens,
Cl2, Br2, I2, is discussed.
Aluminium-27 nuclear magnetic resonance in aqueous solutions of its chelates with hydroxy carboxylic acids
Authors: Toy AD , Smith TD , Pilbrow JR
Published: September 2010

Measurements of 27Al
nuclear magnetic resonance of aqueous solutions containing aluminium chelates
of hydroxy carboxylic acids show that the signal intensity depends to a marked
extent on the pH of the solution. This effect has been interpreted in terms of
polymerization of the aluminium chelates which results in a broadening of the
signal through magnetic dipole-dipole coupling between the various 27Al
nuclei.
Rates of N-methylation of azoles with methyl iodide and dimethyl sulphate
Authors: Deady LW
Published: September 2010

The rates of quaternization
of various azoles and their benzo derivatives with dimethyl sulphate, and with
methyl iodide in dimethyl sulphoxide, are reported. Reaction rates are
controlled mainly by the inductive effect of the other hetero atom and there is
a good correlation between rate of quaternization and basicity of the azole.
Electron impact studies. LXXX. Hydrogen-scrambling processes in 'doubly charged ion' mass spectra
Authors: Blumenthal T , Bowie JH , Hart SG
Published: September 2010

A device is described which
allows the measurement of ?doubly charged ion? mass spectra on the m/e 300 mass
range of an Hitachi Perkin-Elmer RMU7 mass spectrometer. The unit gives a
sensitivity enhancement 110 times that described in previous papers, and has
been used to study hydrogen-scrambling and metastable processes which occur in
the ?doubly charged ion? spectra of a range of simple benzenoid derivatives.
Acronycine-synthetic studies
Authors: Lahey FN , Stick RV
Published: September 2010

Nordihydroacronycine, which
can readily be converted into acronycine, was obtained in very low yield by
methylation of the crude product of condensation of
2,2-dimethylchroman-5,7-diol and anthranilic acid, the main product being the
linear isomer of the desired compound.
Organothallium compounds. VIII. Arenesulphinatodiorganothallium(III) derivatives
Authors: Deacon GB , Garg VN
Published: September 2010

The arenesulphinatodiorganothallium(~~~) complexes R2Tl(02SR') (R = Et,
Me, Ph, or C6Fj ; throughout R' = Ph or p-MeC6H4) have been prepared by reaction
of the appropriate diorganothallium(111) halides and silver arenesulphinates, and gave
the complexes Et2(phen)T1(02SR'), impure Me2(phen)T1(02SR'), Ph2(phen or bpy)Tl-
(02SR'), (C6F,)2(phen, bpy, py, or Ph3PO)T1(O2SRf), and (C6Fj)2Ph3AsOT1(02SPh)
on reaction with the appropriate ligands. Attempts to prepare R2(bpy)T1(02SPh)
(R = Et or Me), (C6F5)2Ph3AsOT1(02S-p-MeC&14), (C6Fj)2Ph3PTl(02SPh), and
Ph2(Ph3AsO)T1(02SPh) failed. The complexes Et2T1(02SRf) are dimeric with bridging
0-sulphinate groups in chloroform, and weak association of the dimeric units is con-
sidered to occur in the solid state. Conclusions are more tentative for R2T1(02SRf)
(R = Me, Ph, or C6F5) derivatives, since insolubility prevented molecular weight and
infrared measurements in solvents of low polarity. However, associated structures with
bridging bidentate 0-sulphinate groups are likely, and sulphur-oxygen stretching
frequencies suggest Me2Tl(02SR') and Ph2T1(02SR') have structures similar to Et2Tl-
(02SR'). The complexes R2LT1(02SR') have monomeric structures with 0-sulphinate
ligands. For L = phen or bpy, the sulphinate groups are either unidentate, giving five-
coordinate thallium, or bidentate, giving six-coordinate thallium, and for L = py,
Ph3P0, or Ph3As0, unidentate sulphinate groups and four-coordinate thallium are
likely.
The interaction of H+, Zn2+, and Cu2+ with adenine and guanine
Authors: Walker WR , Guo JM , Li NC
Published: September 2010

The interactions of H+,
Zn2+, and Cu2+ with adenine and guanine have been
investigated by N.M.R. studies in dimethyl sulphoxide (Me2SO). The
compounds Zn(adenine)HCl3, Zn(guanine)HCl3, (adenine)HCl,
(adenine)2HCl, (guanine)HCl,H2O and (guanine-H)2[ZnCl4]4H2O
have also been prepared and studied in Me2SO. The last compound as
well as (adenine)2HCl have not been reported previously. N.m.r. spectra are
concentration-dependent and also depend upon the hydrogen ion activity. This
work has shown that there is little correlation between solid state structures
and interactions in solution and, further, that selective line broadening by
the para- magnetic Cu2+ ion is not unequivocally diagnostic of the
binding site in these systems.
Resolution of (±)-adrenaline
Authors: Hawkins CJ , Klease GT
Published: September 2010

The resolution of (�)-adrenaline
with ethylenediaminetetraacetatocobal- tate(III) is described. Both isomers
were obtained in an optically pure state in good yield with a high percentage
recovery of the resolving agent.
Synthesis and some reactions of the N-Tosyl derivative of indoles and 2,3-Dihydrocarbazol-4(1H)-one
Authors: Evans DD
Published: September 2010

The preparation and some
reactions of the N-tosyl derivative of 3-(2?- nitropropenyl)indole
(1), indole-3-carbaldehyde (2), indole-3- glyoxylamide (3), and 2,3-di-hydrocarbazol-4(1H)-one (7) are described. The N-tosylnitropropenyl derivative (1) was converted into α-methyl-1-
tosyltryptamine, and the reaction of
2,3-dihydro-9-tosyl-carbazol-4(1H)-one (7) with ethoxyethynylmagnesium bromide and in the Mannich and Cope-Knoevenagel reactions are described.
Isolation of methyl homohygrinate from Solanum sturtianum (Solanaceae)
Authors: Bremner JB , Cannon JR , Joshi KR
Published: September 2010

Methyl homohygrinate has
been isolated from the tops of Solanum sturtianum F. Muell.
Oxidative cyclizations. IV. Isokinetic relationship in the oxidation of orthosubstituted anilines with (diacetoxyiodo)benzene
Authors: Dyall LK
Published: September 2010

The rates of oxidative
cyclization of 11 ortho-substituted anilines by (diacetoxyiodo)benzene have
been measured in toluene-acetic acid solution. The activation parameters give a
precise fit to an isokinetic relationship, which indicates that a common reaction
mechanism is followed. This mechanism applies to amines from the benzene,
naphthalene, and anthraquinone families, with nitro and various carbonyl and
arylazo groups as the ortho substituents.
c. Internal rotation of the nitroso group in p-substituted nitrosoanilines by the density matrix line-shape method
Authors: Buckley PD , Furness AR , Jolley KW , Pinder DN
Published: September 2010

Density matrix theory has been applied to study the barrier to internal rotation about the Ar-NO
bond in N,N-dimethyl-p-nitrosoaniline and N,N-diethyl-p-nitrosoaniline. Theoretical fits to
experimental n.m.r. spectra have been obtained in the range - 30°C to +40°C. Activation parameters have been determined and compared with those obtained by more approximate methods.
Some cobalt(II) complexes of 2,2'-Dithiodipyridine and 4,4'-Dithiodipyridine
Authors: Bridson ME , Walker WR
Published: September 2010

The following cobalt(11)
complexes containing the chelate 2,2'-dithiodipyridine (αdtp)
and the isomeric chelate 4,4'-dithiodipyridine (γdtp)*
have been prepared and investigated: Co(αdtp)X2
(X = Cl, Br,I and NCS), Co(γdtp)Cl2 and Co(γdtp)2X2
(X = I and NCS). All, except the first three, are described for the first time.
Physicochemical investigations indicate that the complexes Co(αdtp)X2 (X = Cl,Br
and I) are tetrahedral monomers and Co(αdtp)(NCS)2
is an octahedral polymer. Co(γdtp)Cl2,
appears to be tetrahedral whereas Co(γdtp)2X2
(X = I and NCS) are octahedral polymers. Although the complete interpretation
of the spectra is rendered difficult by the ligand bands occurring at lowfrequencies, far-infrared
spectra have provided evidence that both nitrogen atoms in αdtp
and γdtp are coordinated in these complexes.
Aluminium corrosion studies. I. Potential-pH-temperature diagrams for aluminium
Authors: Lowson RT
Published: September 2010

The
potential-pH-temperature relationships for the aluminium-water system have been
calculated by the methods of de Bethune, Khodakovskiy,
Criss and Cobble, and Helgeson
and a critical comparison made. The Criss and Cobble
method produced the most consistent results and was used to construct a
corrosion diagram for the range 25-300�C. The effect of the hydrolysed ions
Al(OH)2+, Al(OH)2+ and Al(OH)30
was also calculated. The work has shown up a temperature effect which should be
taken into account when designing and operating aluminium circuits in which
different parts are operated at different temperatures.
Solution-growth, crystal system and transformation of crystals of phase II RbNO3
Authors: Courtenay EW , Kennedy SW
Published: September 2010

It has proved possible to
grow small single crystals of phase 11 of rubidium nitrate above 220�C.� These are used to examine the crystal system
and polymorphic transformation of this phase. Rhombohedralsymmetry has been deduced
from polarized light microscopy. The crystals undergo a regular shape change in
the transformations 11 → I → 11. This implies a coordinated
structural rearrangement which can be related to a lattice deformation.
S-Dealkylation reactions of palladium(II) complexes of some phosphorus-sulphur and arsenic-sulphur chelates
Authors: Lockyer TN
Published: September 2010

Mono- and bis-chelated palladium(11) complexes of o-methylthiophenyldiphenylphosphine
(P-SCH3),* bis(o-methy1thiophenyl)phenylphosphine (CH3S-P-SCH,), and their arsenic analogues,
o-methylthiophenyldiphenylarsine (As-SCH,) and bis(o-methy1thiophenyl)phenylarsine (CH3S-As-
SCH,), have been synthesized. The mono-chelated compounds Pd(X-SCH3)12 and Pd(CH,S-X-
SCH3)12 (X = P or As) undergo S-demethylation in hot dimethylformamide to yield Pd2(X-S)212
and Pd2(CH,S-X-S)212. In the presence of one mole excess of free ligand, the dealkylation reaction
affords bis-demethylated products Pd(X-S), and Pd(CH3S-X-S),. A mixed ligand species
Pd(CH,S-P-S)(CH3S-As-S) was also isolated. These bis-demethylated compounds react with
a variety of alkylating agents, RCH2Y, to give a complex of the original or of a different thioether
ligand, of the form Pd(X-SR)Y2 or Pd(CH3S-X-SR)Y2 (R = Et, Bu and p-N02C6H4CH2;
Y = halogen). In all complexes of CH3S-X-SCH,, including demethylated products, it is suggested
that one thiomethyl residue is not coordinated and that they are essentially four-coordinate and
square-planar.
All four ligands yield the bis-chelated cation species, [Pd(~helate)~]~+, which were isolated as
perchlorate salts. The arsenic chelates alone afford the bis-chelated halides Pd(As-SCH3),Y2 and
P~(CH,S-AS-SCH,)~Y~, which are non-electrolytes in non-aqueous solution. This fact is attributed
to their undergoing a fast rearrangement to form the mono-chelated species. This was confirmed
by conductimetric titrations. Where possible, structures and rearrangements were substantiated
by proton magnetic resonance spectroscopy.
Reaction of a basic chromium(III)-zirconium(IV) sulphate complex with amino acids
Authors: Davis MH , Scroggie JG
Published: September 2010

The basic chromium(111)-zirconium(1V)
sulphate complex isolated previously [Na2Zr3Cr2(S04)4-
(OH)12,6H2O = compound A] has been shown to react with a
series of amino acids at moderately acidic pH values to produce a good yield of
either a 1 : 1 or 2 : 1 amino acid-compound A complex. These were usually
relatively insoluble, electrically neutral complexes in which sulphate groups have been displaced by amino acid residues.
The reaction involves coordination of the amino acid through the carboxyl group
(although some evidence was obtained for nitrogen-coordination when the
reaction was performed by boiling with an excess of amino acid) and is
accompanied by an increase in the number of moles of bound water from 6 to 9. A
2 : 1 cationic complex was also isolated from reaction of an excess of α-alanine with compound A. Amino acid methyl esters were
shown to react with compound A after demethylation to form the same 1 : 1 complex
as obtained from the corresponding free amino acid.
The synthesis of a series of regularly annelated 2-methylheterohelicenes
Authors: Lehman PG , Wynberg H
Published: September 2010

A series of regularly annelated thia-heterohelicenes
has been prepared by a new progressive annelation
technique based on the key intermediate, 2-methylbenzo[l,2-b:4,3-b?]dithiophen.
Supposed acetyl migration from the 3β- to the 19-hydroxyl group in Δ5-steroids
Authors: Baigent DR , Lewis KG
Published: September 2010

The product of
monotritylation of 3β,19-dihydroxyandrost-5-en-17-one is the 3β-trityl
ether, not the 19-trityl ether as previously proposed. In consequence the
product of acetylation of the monotrityl ether is 19-acetoxy-3β-trityloxyandrost-5-en-17-one
and thus acid-catalysed detritylation of this compound yields directly the
19-acetoxy derivative without the invoking of an acid-catalysed rearrangement.
The isomeric 3β-hydroxy-19-trityloxyandrost-5-en-17-one has been prepared
as well as a number of 3β-tritylated Δ5-steroids which
have been used to study the influence of the trityl ether group upon p.m.r.
chemical shifts in this series.
The 9-Decalyl and related cations. II. Acetolysis of 3-(2'-Methylenecyclohexyl)propyl derivatives
Authors: Gream GE , Serelis AK
Published: September 2010

The acetolysis of two
3-(2'-methylenecyclohexyl)propyl derivatives (the p-nitrobenzenesulphonate and bromide) provides a π-route to
9-decalyl cations which, on the basis of the composition of the products, are
very similar to those formed from 4-(cyclohex-1'-enyl)but-1-yl derivatives.
Thermodynamic properties of liquid mixtures: Selection of the pure liquid parameter
Authors: Fenby DV , Pasco NF
Published: September 2010

There has recently been a
revival of interest in theories of liquid mixtures based on analytic equations of
state for pure fluids. We have shown that the method used to determine the
parameters of the pure-liquid equation of state has a significant effect on the
excess thermodynamic properties obtained from such theories.
Crystal structure of 'calcium sulphosilicate', Ca5(SiO4)2SO4
Authors: Brotherton PD , Epstein JM , Pryce MW , White AH
Published: September 2010

The crystal structure of
the title compound, obtained as a coating from a lime kiln, has been shown to
be isostructural with that of the mineral silicocarnotite and refined by full-matrix least-squares
methods (570 independent diffractometer reflections). The lattice parameters of
the latter compound were used to initiate the procedure, the final residual
being 0.042. The correspondence in detail between the two structures is close.
Crystal data: orthorhombic, Pcmn, a =
10.182(1), b = l5.398(2), c = 6.8500(9)
�, Z = 4.
The mass spectra of o-phenylenediamine, o-phenylenediarsine and some related compounds of arsenic and antimony
Authors: Henrick K , Shewchuk E , Trigwell KR , Wild SB
Published: September 2010

The title compounds,
together with the tetramethyl derivatives, o-phenylenebis(dimethy1amine)
and o-phenylenebis(dimethylarsine), and a series of dissymmetrical diarsines and 4-substituted o-phenyl- enediarsines have been
subjected to electron bombardment at 70 eV. The
nitrogen compounds show fragmentation patterns corresponding to those found for
aniline and its N-substituted
derivatives. The diarsines undergo simple stepwise
loss of alkyl substituent radicals and, in the case of the halogen and phenyl
arsenic substituted compounds, undergo migration of these groups and combination
reactions with arsenic containing ions.
Organophosphorus compounds. XIII. Synthesis of some 4-Phenylperhydro-1,4-azaphosphorines
Authors: Collins DJ , Rowley LE , Swan JM
Published: September 2010

The reaction of
phenylphosphonic dichloride with two mole equivalents of vinylmagnesium bromide
in tetrahydrofuran at ? 70� gave 72% of divinylphenylphosphine oxide, which
when heated under reflux for 6h with a 20% excess of aqueous methylamine or of
aqueous allylamine afforded almost quantitative yields of 1-methyl- or
1-allyl-4-phenylperhydro-1,4-azaphosphorine 4-oxide, respectively. These
compounds were converted into the corresponding phosphine sulphides in high
yields. An attempt to prepare 4-phenylperhydro-1,4-azaphosphorine 4-oxide by
the reaction of divinylphenylphosphine oxide with ammonium hydroxide and sodium
hydroxide at 100� for 26h gave, instead, a low yield of
4-phenylperhydro-1,4-oxaphosphorinane 4-oxide. Reaction of vinylmagnesium
bromide with diphenylphosphinic, diphenylphosphinothioic and phosphoryl
chlorides are described.
Thermal decomposition of alcohols. I. 2-Methylbutan-2-ol (t-Pentyl alcohol)
Authors: Johnson WD
Published: September 2010

The thermal decomposition
of 2-methylbutan-2-ol has been investigated from 432 to 570�C, over initial
pressures ranging from 26 to 288 mmHg, and in the presence of toluene from 519
to 570�C. The decomposition is first order and homogeneous, involving the unimolecular elimination of water from the alcohol.
2-Methylbut-1-ene and 2-methylbut-2-ene decompose through a consecutive
reaction under these conditions. The Arrhenius
equation giving the variation of the first-order rate constants with
temperature was found to be (R = 8.31 J mol-1 K-1)

k = 1011.8 exp(- 23OOOO/RT) s-l
Polymorphic transformation II → I in potassium nitrate: multiple orientations
Authors: Kennedy SW , Odlyha M
Published: September 2010

The crystal structural
transformation from aragonite-type KNO3I produces a variety of
orientations as shown by polarized light microscopy. Extinction directions are listed and include
one which is consistent with the reported orientation for CaCO3 and
one consistent with

another orientation previously reported for KNO3.
Interfaces are produced parallel to the pseudohexagonal
basal plane of 11, but the basal planes of the two phases do not necessarily
form the interface.
An N.M.R. study of some esters and lactones derived from cineolic anhydride
Authors: Rae ID , Redwood AM
Published: September 2010

Cineolic anhydride is attacked by nucleophiles exclusively at
its more exposed carbonyl group. The dimethyl ester of cineolic
acid has been studied by proton N.M.R. spectroscopy and its conformation assigned.
Similar assignments have been made for cineolic
anhydride and two lactones derived from it, examples of the
3,6-dioxabicyclo[3,2,2]nonane ring system. In each
case the N.M.R. signal of the methine proton is
simplified by the use of a lanthanide shift reagent so that the conformation
can be deduced. The shift reagent removes the effect of virtual coupling to the
methine proton.
Metal complexes of styrene-vinylpicolinic acid copolymer
Authors: Paton R , Watton EC , Williams LR
Published: September 2010

A
styrene-2-methyl-5-vinylpyridine copolymer was prepared and the methyl group
was then converted into a carboxyl group by the rearrangement of the N-oxide. The formation constants of the
copolymer-metal complexes were determined and compared with those formed by picolinic acid.
Correlations of thermodynamic data with structural parameters for cation olefin complexation
Authors: Natarajan GS , Venkatachalam KA
Published: September 2010

Thermodynamic data for
formation of complexes of silver and cuprous ion with a series of liquid monoolefins are discussed from the angle of the influence
of structural parameters of the olefins on the data. This influence may often
be masked when comparing log K values owing to marked changes in ΔS�
values. Opposing trends in thermodynamic data for desolvation
may explain contradictions observed in the literature with increasing alkyl
substitution.
Studies on intramolecular alkylation. V. Intramolecular alkylation of the aromatic ring in tetrahydronaphthyl diazomethyl ketones
Authors: Beames DJ , Klose TR , Mander LN
Published: September 2010

The acid-catalysed
reactions in weakly nucleophilic environments of 2-diazoacetyl-l,2,3,4-tetrahydronaphthalene
(ll), of 6-diazoacetyl-5,6,7,8-tetrahydro-2-naphthol (2), of
6-diazoacetyl-5,6,7,8- tetrahydro-2-naphthyl methyl ether (3) and its 2,8 and
2,5 isomers (14) and (17), and of 6-diazo-
acetyl-5,6,7,8-tetrahydro-6-trifluoroacetoxy-2-naphthyl methyl ether (9) have
been studied. Several of the spirocyclohexa-2,5-dienone derivatives prepared
thus, (4), (8) and (16), provide potential intermediates or models for the
synthesis of tetracyclic diterpenoids.
Thermodynamics of metal-ligand bond formation. XII. Adducts of Monothio-β-diketone complexes with pyridine and bipyridine
Authors: Dakternieks DR , Graddon DP
Published: September 2010

Thermodynamic data are
reported for the addition of pyridine and bipyridine
in benzene solution to monothio-β-diketone
complexes, ML2, of nickel(11), copper(11), zinc(11) and mercury(11).
NiL2 gives NiL2(py)2 and NiL(bpy);
ZnL2 gives ZnL2(py) and ZnL2(bpy); in both
cases the data show that bipyridine is bidentate. CuL2
gives CuL2 (py) and CuL2 (bpy), with almost equal
enthalpies of formation, but the higher stability of CuL2(bpy) shows
bipyridine is probably bidentate. HgL2
gives HgL2(py) and a reaction with bipyridine
which shows that an extremely unstable adduct is formed. All data were obtained
by calorimetric titration.
Photodechlorination of the diels-alder adduct of 1,4-Dihydro-1,4-epoxynaphtalene and 1,2,3,4-Tetrachloro-5,5-dimethoxycyclopentadiene
Authors: Bremner JB , Hwa Y , Whittle CP
Published: September 2010

Ultraviolet irradiation in
ether of the Diels-Alder adduct, (1), of
1,4-dihydro-1,4-epoxynaphthalene and
1,2,3,4-tetrachloro-5,5-dimethoxycyclopentadiene, gave 1,2,4-trichloro-ll
,ll-dimethoxy-1,4,9,-9a,10,10a-hexahydro-9,10-epoxy-1,4-methanoantacene
(2) and 1,2,3-trichloro-ll,ll-dimethoxy-1,4,9,9a,10,10a-hexahydro-9,10-epoxy-1,4-methanoanthracene
(3) as the main products. The formation of (3) represents a new photochemical
pathway in these chlorinated polycyclic systems.
The D.C. polarography of azobenzene in pyridine
Authors: Boto KG , Thomas FG
Published: September 2010

The d.c. polarography of
azobenzene, sulphuric acid, acetic acid and mixtures of azobenzene with each of
these acids in pyridine is reported. Azobenzene reduces in two one-electron
steps, as is thecase in acetonitrile and
dimethylformamide. Sulphuric acid is reduced in two irreversible steps corresponding
to the reduction of the solvated proton produced by the first and second
dissociationsof sulphuric acid,
respectively. Acetic acid exhibits a single irreversible proton reduction wave.On addition of acid,
azobenzene is reduced to hydrazobenzene via azoniumbenzene formed by protonation
of azobenzene. Two such azonium waves are recorded in the polarograms when
sulphuric acid is present corresponding to the two-proton dissociation steps of
sulphuric acid. With acetic acid only one azonium wave is noted. In pyridine
the reduction of azobenzene in the presence of proton donors is similar to that
observed in acetonitrile. The differences noted between thebehaviour in the two
solvents arise from the different Lewis basicities of pyridine and
acetonitrile.
The synthesis of meso-Hexoestrol[3,4-D2] and some related specifically deuterated compounds
Authors: Collins DJ , Hobbs JJ
Published: September 2010

Condensation of p-methoxyphenylacetonitrile
with p-methoxypropiophenone
in the presence of sodium hydride in dimethyl sulphoxide
at 65� gave (Z)-(23%) and (E)-2,3-bis(p-methoxyphenyl)pent-2-enenitrile(16%).
The reduction of this α,β-unsaturated nitrile with lithium aluminium
deuteride in tetrahydrofuran, and workup with D2O or with H2O,
gave high yields of erythro-2,3-bis(p-methoxy-phenyl)valeronitrile[2,3-D2], or -[3-D], respectively.
Conversion of the dideuteronitrile into the
corresponding methyl ketone with methylmagnesium
iodide, followed by a hydride reduction-tosylation-hydride
reduction sequence, then demethylation, afforded meso-hexoestrol[3,4-D2].
Dehydration of (3RS,4SR)-3,4-bis(p-methoxyphenyl)hexan-2ξ-ol[3,4-D2]
with phosphoryl trichloride in pyridine gave 3,4-bis(p-methoxyphenyl)hex-2-ene[4-D]. Reduction of erythro-2,3-bis(p-methoxy-
phenyl)valeronitrile[3-D] to the corresponding amine
followed by quaternization and Hofmann elimination
afforded 2,3-bis(p-methoxypheny1)pent-1-ene[3-D].
The synthesis and reactions of some carcinogenic N-(2-Phenanthryl)hydroxylamine derivatives
Authors: Calder IC , Williams PJ
Published: September 2010

The synthesis of
2-nitrophenanthrene from 9,l0-dihydrophenanthrene is reported. Some
2-substituted phenanthrene and 9,l0-dihydrophenanthrene
hydroxylamine derivatives have been prepared and the structure of the
rearrangement products determined.
Dipole moments and conformations of di(nitrophenyl) disulphides
Authors: Fairhall LB , Ritchie GLD
Published: September 2010

Experimental dipole moments
(1030μ/Cm) are reported and analysed for the following as
solutes in benzene at 25�C:di(4-nitrophenyl)
disulphide (12.6):di(3-nitrophenyl)
disulphide (14.5):di(2-nitrophenyl)
disulphide (17.6).
Chemistry of the Podocarpaceae. XLIX. Isomerization of 12-Methoxy-19-norpodocarpatetraenes
Authors: Cambie RC , Grigor BA , Hayward RC , Nielson AJ
Published: September 2010

Methods for isomerization
of the 12-methoxy-19-norpodocarpatetraene mixture obtained from oxidative
decarboxylation of 12-methoxypodocarpa-8,11,13-trien-19-oic acid (1) with lead
tetraacetate have been examined. Acid-catalysed isomerization gives a mixture
of the endocyclic isomers (11) and (19) while
iodine-catalysed isomerization gives a mixture enriched in the isomer (19) to
the extent of 80%. Metal-catalysed decarbonylation of
the acid chloride (6) and oxidative decarboxylation of the acetoxy acid (7) have
also been examined.
Spin-forbidden bands in the aqueous solution spectra of the Trisoxalato- and Trismalonato-chromium(III) anions
Authors: Olliff RW , Rands DB , Shooter D
Published: September 2010

The aqueous solution
spectra of the trisoxalato- and trismalonato-chromium(111)
anions show a number of weak spin-forbidden bands in the visible and near
infrared. These bands are shown to arise from vibronic
coupling rather than from the presence of a trigonal field. The 4A2
→ 2E transition is shown to be characteristic of several
chromium-oxalato complexes.
Thio derivatives of β-diketones and their metal chelates. XVI. Nickel(II), palladium(II), platinum(II), zinc(II) and cobalt(III) chelates of some new fluorinated Monothio-β-diketones
Authors: Das M , Livingstone SE
Published: September 2010

The new fluorinated β-diketones
RCOCH2COCF3 (R = p-ClC6H4,
m-ClC6H4, m-BrC6H4, m-MeC6H4
and m,p-C1,C6H3)
have been prepared. The monothio-β-diketones
RC(SH)=CHCOCF3 derived from these β-diketones were also
prepared. Complexes of these monothio-β-diketones
and of p-FC6H4C(SH)=CHCOCF3
with nickel(11), palladium(11), platinum(11), zinc(11) and coba1t(111) have
been prepared and characterized. All the complexes are stable and display sharp
melting points.
Thio derivatives of β-Diketones and their metal chelates. XVII. Mass spectra of iron(III) and ruthenium(III) chelates of some fluorinated Monothio-β-diketones
Authors: Das M , Livingstone SE
Published: September 2010

The mass spectra of the
iron(111) and rhodium(111) chelates of the fluorinated monothio-β-diketones
RC(SH)=CHCOCF3 (R = Ph,p-MeC6H4,
2-thienyl) have been obtained. Whereas the ruthenium(111) chelates give a peak
for the molecular ion, the iron(111) chelates do not, due to thermal
degradation to the iron(11) complex Fe(RCS=CHCOCF3)2
which then undergoes reactions in the mass spectrometer. Fluorine migration
occurs with two of the iron chelates but not with the ruthenium chelates.
Mechanisms are proposed for the reactions of the ruthenium chelates.
Electrochemical investigation of contact angle and of flotation in the presence of alkylxanthates. I. Platinum and gold surfaces
Authors: Gardner JR , Woods R
Published: September 2010

The contact angle between a
nitrogen bubble and platinum or gold electrode surfaces immersed in xanthate
solutions has been determined as a function of the quantity of dixanthogen on
the metal surface for the methyl, ethyl and butyl compounds. Significant angles
result from fractional coverages, but multilayers are required before the maximum angle,
characteristic of the particular alkyldixanthogen, is
reached. The quantity of dixanthogen required to float a particulate bed
electrode of gold spheres was determined for a number of alkylxanthates.
The required quantity varied from multilayers for
methyl to low fractional coverages for the longer
chain compounds. Nevertheless the static contact angle corresponding to these coverages was in each case found to be close to 55� for the
three alkyldixanthogens studied. When butyl- or
pentyl-xanthates were used at typical concentration
levels applicable to practical situations (10 p.p.m.),
flotation was inhibited when the quantity of dixanthogen formed was more than two
to four times greater than the minimum amount necessary for flotation to occur.
This inhibition arose from flocculation of the gold particles.
Modification of a Varian HA60-IL N.M.R. spectrometer for measurement of carbon-13 spectra by audio-sideband sweeping
Authors: Doddrell DM , Hanson FB , Kenny RJ , Marker A , Riggs NV
Published: September 2010

Conversion of a
conventional modulated-field proton magnetic resonance spectrometer (Varian
HA60-IL) for measurement of natural-abundance carbon-13 N.M.R. spectra by
audiofrequency (a.f.) sideband sweeping with internal homopolar field-frequency
lock is described. The manufacturers modified the basic instrument so that
sweep, multiscan accumulation (signal averaging), and data plotting were under
control of a minicomputer (Varian 620/i with 8-K( memory), supplied an ref.
transmitter/receiver unit and probe of appropriate frequency (15.086 MHz), the
probe being also tuned to accept the corresponding proton-decoupling frequency
(60 MHz), and suggested use of 13C-isotopically enriched methyl
iodide as internal homopolar lock sample. In practice, under the high r.f. and
a.f. powers required, the a.f. range to be swept must be chosen to avoid
regions where the baseline response is highly frequency-dependent. Choice of a
suitable fixed lock a.f, then permits use of an inexpensive proton-decoupler
based on a simple crystal oscillator whose centre frequency can be 'pulled' a
few hundred hertz for optimum decoupling, noise-modulated, and appropriately
amplified. Phase differences between lock and observed signals are corrected
with a simple a.f. phase shifter in the analytical channel. Even in the 'best'
baseline region, residual 'roll' accumulates, but usually satisfactory major
corrections may be effected rapidly by means of a sextic polynomial curve-
fitting subroutine. Integration of peak areas is not feasible. When the sample
and its dielectric constant are changed, it is important to retune the probe
receiver coil for maximum response.
The determination of the absolute configuration of vicinal diols
Authors: Hamon DPG , Massy-Westropp RA , Pipithakul T
Published: September 2010

Horeau's method for the determination of absolute
configuration has been used successfully for the determination of configuration
of some cyclic and acyclic vicinal diols. The examples include the four
isomeric pinane-2,3-diols and some diols which were prepared from (-)-(S)-ethyl
lactate.
Molar Kerr constants of six N-Aryl-4-pyridones as solutes in benzene or dioxan
Authors: Batts BD , Le Fevre RJW , Madeley AJ
Published: September 2010

The molar Kerr constants of
six N-aryl-4-pyridones as solutes in
benzene or dioxan have been determined.
Hydrolysis of Monothio-β-diketones. II. Hydrolysis of three fluorinated Monothio-β-diketones
Authors: Leban M , Fresco J , Das M , Livingstone SE
Published: September 2010

The rapid decomposition of
the fluorinated monothio-β-diketones RC(SH)=CHCOCF3, 4-(3?-bromophenyl)-1,1,1-trifluoro-4-mercaptobut-3-en-2-
one (R = m-BrC6H4), 4-(4?-bromophenyl)-1,1,1-trifluoro-4-mercaptobut-3-
en-2-one (R = p-BrC6H4) and 1,1,1-trifluoro-4-mercaptopent-3-en-2-one(R
= Me), in acid solution has been shown to occur by hydrolytic cleavage to yield
the ketone RCOCH3, hydrogen sulphide and probably trifluoroacetic
acid. The pseudo first-order rate constants for these compounds are (8.0�0.3)x
10-3, min-1, (6.0 � 0.6) x 10-3 min-1
and 0.12�0.01 min-1, respectively. The greater vulnerability of
1,1,1- trifluoro-4-mercaptopent-3-en-2-one, compared to the other two
monothio-β-diketones, towards hydrolytic cleavage is related to the nature
of the R substituent in that conjugation involving the terminal aromatic ring
stabilizes the monothio-β-diketone.
Pyrazolidine-3,5-diones with heterocyclic substituents. I. Preparation of 3-Phenyl-1,2,4-triazolyl derivatives
Authors: Woodruff M , Polya JB
Published: September 2010

The preparation of
pyrazolidine-3,5-diones substituted in the 1- position by 3-phenyl-1,2,4-triazol-5-yland
mono- or di-substituted in the 4-position by aliphatic or carbocyclic groups is
described, together with that of some further substituted derivatives and byproducts,
including s-triazolo[1,5-a]-pyrimidines. Attention is drawn to problems of
tautomerism and reactivity which are to be treated in subsequent papers.
E.S.R. studies of some polycyclic semiquinones and derived radicals
Authors: Hewgill FR , Mullings LR
Published: September 2010

Oxidation of various 2,2?-dihydroxybiphenyls
and binaphthyls gave ex. spectra which revealed no evidence of equal sharing of
the unpaired electron between the two halves of the molecule. By contrast
reduction of 3,3?- and 4,4?-di-t-butyl-2,5,2?,5?-diphenoquinones and of 2,2?-di-
1,4-naphthoquinone gave symmetrical spectra indicating rapid spin exchange
between the rings. The species responsible are radical monoanions. Secondary
radicals formed from naphthoquinones indicated the occurrence of hydroxylation.
The formation of a substituted furan was also observed. The absence of
splitting by one of the aromatic ring hydrogens in 2-hydroxy-1,4-naphthosemiquinones
was noted and examination of a series of
bromo-2-hydroxy-3-phenyl-1,4-naphthoquinones showed that splitting decreased in
the order aH(6) > aH(8) > aH(5) > aH(7)
with aH(7), like aH(3) in the semiquinones without a
phenyl substituent at this position, usually being too small to be resolved.
Entrainment of liquid films by vertically moving thin rods
Authors: Nicol SK , Wilson GR
Published: September 2010

When a thin rod is
withdrawn vertically from a liquid bath a film of that liquid adheres to the
rod. A short review of the theories describing this process is given. The
application of these theories to three model systems using glycerol solution,
kerosene and an oil as the coating liquids is discussed. The effect of surface
active agents on the equilibrium film thickness is explained in terms of
additional forces at the liquid-air interface impeding film drainage.
Behaviour of some niobium(V), tantalum(V) and molybdenum(VI) compounds in disulphuric acid
Authors: Bali A , Malhotra KC
Published: September 2010

Pentaoxides and
oxychlorides of niobium and tantalum and ammonium metaniobates and tantalates
form H [NbO(HSO4)4] and H [TaO(HSO4)4]
while pentahalides form H[M(HSO4)6] when dissolved in
disulphuric acid. These acids behave as non-electrolytes in this solvent. At
higher concentrations, there is indication of polymerization. Ammonium
molybdate and molybdenum pentaoxide form MoO2(HSO4)2
while molybdenum pentachloride forms H [Mo(HSO4)6] when
dissolved in disulphuric acid.
Septanose carbohydrates. I. Acid-catalysed reaction of D-glucose with acetone
Authors: Stevens JD
Published: September 2010

Two septanose derivatives of D-glucose, 1,2:3,4-di-O-isopropylidene-α-D-glucoseptanos(e4 a) and
2,3:4,5-di-O-isopropylidene-D-glucoseptanos(e5 a), have been isolated from the mixture of products
formed by treating D-glucose with acidified acetone. Acid hydrolysis of (4a) yielded 1,2-O-isopropylidene-
α-D-glucoseptanose which has been converted into a mixture of (4a) and a third D-glucoseptanose
derivative, 1,2:4,5-di-O-isopropylidene-α-D-glucoseptanose (8a). Methylation of (5a) yielded the
two D-glucoseptanoside derivatives, methyl 2,3:4,5-di-O-isopropylidene-α-D-glucoseptanoside and
methyl 2,3:4,5-di-O-isopropylidene-β-D-glucoseptanosiwde, which have been selectively hydrolysed
to give methyl α (and β-)-D-glucoseptanosides. Conformations of these various septanose compounds
are proposed on the basis of n.m.r. parameters and these conformations are compared with those
found in the solid state by X-ray analysis.
Photochemical syntheses. IX. Synthesis and reactions of 8b-Methoxy- and 4,8b-Dimethoxy-l,2-diphenyl-2a,8b-dihydrocyclobuta[a]naphthalene
Authors: Teitei T , Wells D , Sasse WHF
Published: September 2010

The photoadduct (2e) has
been prepared from 1,4-dimethoxynaphthalene and converted into the title
compounds (1*d) and (1e). These compounds reacted with acetic acid,
trifluoroacetic acid, formic acid or hexamethylphosphoric triamide to give
(after hydrolysis) the deoxybenzoin derivatives (6a) or (6b). Ultraviolet
irradiation converted (1*d) into (2d) and (1e) into (2e) at rates which were
slower than the corresponding reactions of the 4-methoxy derivatives (1d), the
4,8b-dimethyl derivative (1f) or the parent compound (1a).
Crystal structure of Bis(hydrazine)bis(hydrazinecarboxylato)cobalt(II)
Authors: Maslen EN , Raston CL , Skelton BW , White AH
Published: September 2010

The crystal structure of
the title compound [Co(N2H4)2(NH2NHCO2)2]
has been determined at 295 K from X-ray diffractometer data and refined by
full-matrix least squares to a residual of 0.059 for the 4985 independent
reflections within the limit 2θ < 100� (Mo Kα
radiation). Crystal data: monoclinic, P21/a, a 9.551(2), b 7.352(2),
c 8.110(1) Ǻ, β 122.38(1)�, Z 2. ��� The compound is isostructural with the zinc
analogue. The cobalt atom lies on a centre of symmetry; it is six-coordinate,
being surrounded by monodentate hydrazine (Co-N, 2.178(2) Ǻ) and bidentate
hydrazinecarboxylate ligands (Co-O, 2.064(2) Ǻ; Co-N, 2.198(2) Ǻ).
2'-O-Methylphysodic acid and hydroxyphysodic acid: two new depsidones from the lichen Hypogymnia billardieri
Authors: Elix JA
Published: September 2010

Two new depsidones, 2?-O-methylphysodic
acid and hydroxyphysodic acid, have been identified as minor constituents of
the lichen Hypogymnia billardieri
(Mont.) R. Filson. The structure of 2?-O-methylphysodic
acid was established by chemical interconversions. The overall substitution
pattern of this depsidone was confirmed by methylation with excess diazomethane,
whereupon methyl 4,2?,4?-tri-O- methylisophysodate
was obtained. Further, a direct comparison showed that this metabolite was
dissimilar from 4-O-methylphysodic acid which has been isolated previously. ��� The structure of hydroxyphysodic acid
followed from the analytical data, spectroscopic properties and chemical
interconversions. This compound is biogenetically unique, since it is the first
depsidone isolated in which the basic orcinol nucleus has undergone further
hydroxylation.
Platinum(II) complexes of 2,2',2',2'-tetrapyridine
Authors: Lip HC , Plowman RA
Published: September 2010

Platinum(II) complexes of
the general formula PtLX2,yH2O where L = 2,2?,2?,2??-tetrapyridine
(tpy), X = I, ClO4, BPh4, y =
0; X = NO3, y = 3, have been isolated. Conductometric and infrared
evidence suggest that the ligand can function as a quadridentate.
Diterpene chemistry. V. Thallium(III) nitrate oxidations of exocyclic olefins
Authors: Grant PK , Liau HTL , Low K
Published: September 2010

The oxidative rearrangement
reported for acyclic and endocyclic olefins with thallium(III) nitrate does not
occur with exocyclic olefins. Allylic nitrate esters or their transformation
products were isolated.
The reduction of HCl dissolved in LiCl-KCl eutectic
Authors: Minh NQ , Welch BJ
Published: September 2010

The cathodic reduction of
hydrogen chloride dissolved in LiCl-KCl eutectic has
been studied by both chronopotentiometry and linear
sweep voltammetry using a platinum electrode. The reduction reaction has been
found to proceed by a reversible one-electron transfer process forming a
soluble product. ��� Diffusion coefficients calculated from
solubility measurements and the electrochemical studies are considerably higher
(e.g. 2.1 x 10-4 cm2 s-1 at 793 K) than most
other solutes in molten salts but in good agreement with results from a less
detailed study. The high value is probably due to the small ionic radius of the
proton as compared to other ions in the lattice of the molten salt system.
Thermodynamic data for addition of bases to low-spin planar nickel(II) complexes with four sulphur-donor atoms
Authors: Ang L , Graddon DP , Lindoy LF , Prakash S
Published: September 2010

Thermodynamic data have
been obtained for the addition of two molecules of pyridine or 4-methyl-pyridine
to bis(perthiobenzoato)nickel(II), bis(dithiobenzoato)nickel(II) and bis(dibenzyldithiocarb- amato)nickel(II)
in benzene solution. Together with previously published data for addition of
bases to nickel(II) xanthates and dithiophosphates, these results show that the
variation of base adduct stabilities of NiS4 complexes with
four-membered chelate rings is due primarily to entropy effects. Possible
origins for these effects are discussed.
Carbon-13 N.M.R. spectra of 6β-Substituted-5α-cholestane-3β,5-diols: γ- and δ-effects
Authors: Blunt JW
Published: September 2010

The carbon-13 N.M.R.
spectra of a series of 6β-substituted-5α- cholestane-3β,5-diols
have been determined. The γ- and δ-shifts associated with those
carbons involved in a direct steric interaction with the 6β-substituent,
i.e. C4, C8, C10 and C19, are found to be upfield or downfield depending on the
nature of the substituent and its geometric relationship to the observed
carbon. In particular, the-δ- shifts at C19 are increasingly downfield as
the size of the substituent is increased.