bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies of the borderline between stepwise and concerted mechanisms of elimination: leaving group effects in elimination of (fluoren-9-ylmethyl)-ammonium ions
Authors: Larkin F , O'Ferrall RAM
Published: September 2010

By comparison with related
substrates β-elimination of (fluoren-9-ylmethyl)trimethylammonium
ion to form dibenzofulvene in methanolic
sodium methoxide is unexpectedly rapid. The reaction
has been investigated as a possible example of an E2 mechanism at the borderline between concerted and stepwise
reaction paths. Evidence from buffer saturation in dimethylaminoacetonitrile
buffers and comparisons with other amine leaving groups suggests, however, that
the mechanism is probably ElcB, with
ionization to a carbanion intermediate rate-determining. As measured by σ*
for the trimethylammonium group the rate of
elimination is 105 times faster than predicted from a Taft correlation of rates
of carbanion formation. Probably this reflects the sensitivity of substituent constants
for monopoles to solvent and reaction, and a rate-enhancing effect from N-methylation of
(fluoren-9-ylmethy1)amine. Comparison of the trimethylammonium
leaving group with eliminations of neutral amines also confirms an earlier
conclusion that intramolecular proton transfer is not an important reaction
path in eliminations of amines activated by a β-fluorenyl group.
On the electrochemistry of pyrylium ions at the mercury electrode. I. Aliphatically substituted ions in acetonitrile
Authors: Garrard WNC , Thomas FG
Published: September 2010

The electrochemical behaviour of 2,4,6-trimethyl- and 2,4,6-tri-t-butyl-pyrylium tetrafluoroborates
in acetonitrile is reported. Both compounds undergo a reversible, one-electron reduction followed
by dimerization of the pyranyl radical. In the case of the trimethyl radical the dimerization is
irreversible whereas the tri-t-butyl radical is in equilibrium with its dimer. Rate constants for the
chemical reactions have been determined.
Photochemical isomerization of 7-aryl-substituted 1H-Azepin-2(3H)-ones. Formation and X-ray structure determination of atropisomeric ketimines
Authors: Becker H , Skelton BW , White AH
Published: September 2010

The structures of two isomeric 3,5-di-t-butyl-2-[(3,5-di-t-butyl-2-hydroxyphenyl){(Z)-methylimino}-
methyl]cyclopent-2-en-1-ones, formed upon photoexcitation of 3,5-di-t-butyl-7-(3,5-di-t-butyl-2-
hydroxyphenyl)-1-methyl-1H-azepin-2(3H)-one in methanol, have been established by X-ray
diffraction, and are found to be examples of atropisomeric ketimines. In both isomers, the geometry
of imino substitution is characterized by intramolecular hydrogen bonding with the phenolic
hydroxyl.
Iminodiacetic acid derivatives of benzimidazole. Synthesis of N-(Benzimidazol-2-ylmethyl)iminodiacetic acids
Authors: Wilson JG , Hunt FC
Published: September 2010

Ten new N-(2-benzimidazolylmethyl)iminodiacetic acids (BIMIDA)* have been synthesized from
the corresponding o-phenylenediamines
via intermediate 2-chloromethyl and 2-aminomethyl benzimid-
azoles as ligands for 99mTc. Anomalies associated with the synthesis
of the iodo-substituted compound are described.
A synthesis and some reactions of 7-Oxabicyclo[2.2.1]heptan-2-one
Authors: Moursounidis J , Wege D
Published: September 2010

Diels-Alder reaction
between furan and α-chloroacrylonitrile gives a
mixture of exo-2-chloro-and endo-2-chloro-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitrile
(4) and (5). Mild hydrolysis affords the corresponding α-chloro acid mixture, from which the endo carboxylic acid may be removed
through iodo lactone formation. Catalytic
hydrogenation of (4) and (5) followed by hydrolysis, acyl azide
formation, Curtius rearrangement, and hydrolysis of
the resulting mixture of a-chloro isocyanates
yields 7-oxabicyclo[2.2.l]heptan-2-one (1) in preparatively
useful amounts. Reduction of (1) gives only endo alcohol, and Baeyer-Villiger reaction proceeds with exclusive bridgehead
atom migration. Thermal decomposition of the sodium salt of the p-toluenesulfonylhydrazone
of (1) affords 7-oxatricyclo[2.2.1 .02,6]heptane.
Oxidations with lead tetraacetate. IV. Oxidations of 1,3-benzodithioles
Authors: Aromdee C , Cole ER , Crank G
Published: September 2010

Oxidations of 2,2-dialkyl and spiro[1,3-benzodithiole-2,1'-cycloalkanes] with lead tetraacetate gave
mainly sulfoxides and disulfoxides. The stereochemistry of these products was elucidated by n.m.r.
spectroscopy. Oxidation of 2-methyl-2-aryl derivatives gave sulfoxides as minor products; here the
main products were derived from attack on the methyl group forming acetoxy, diacetoxy, formyl
and carboxylic acid derivatives and ring cleavage products. 2,2-Diaryl derivatives also formed small
amounts of sulfoxides but ring cleavage products were predominant. Monosubstituted benzodithioles were very reactive and produced a variety of oxidation products, mostly unidentified.
Organophosphorus compounds. XIX. Synthesis of 2,3-Dihydro-1 H-1,2-benzazaphosphole 2-oxides, variously substituted on nitrogen and phosphorus, by N-P cyclization of zwitterionic intermediates
Authors: Collins DJ , Drygala PF , Swan JM
Published: September 2010

2-Phenyl-2,3-dihydro-1H-1,2-benzazaphosphole 2-oxide (7a) was
prepared by thermolysis of the corresponding
zwitterionic amino phosphinic acid (4), or its
hydrochloride salt (1). Thermolysis of methyl
(2-aminobenzy1)phenylphosphinate (5a) was accompanied
by intermolecular O→N transmethylation to give,
after cyclization, l-methyl-2-phenyl-2,3-dihydro-1H-1,2-benzazaphosphole 2-oxide (9a); similarly, the ethyl ester
(5b) gave the N-ethyl heterocycle (9b). Reaction of 2-phthalimidobenzyl bromide
(13a) with diethyl methylphosphonite (14b) gave ethyl
(2-phthalimidobenzy1)methylphosphinate (15a).
Hydrolysis of (15a) afforded (2-aminobenzyl)- methylphosphinic
acid (16), and thermolysis of this produced
2-methyl-2,3-dihydro-lH-1,2-benzaza- phosphole 2-oxide (18a). 1-Methyi-2-methoxy-2,3-dihydro-1H-l,2-benzazaphosphole 2-oxide (24) was
synthesized in an analogous manner. Base catalysed N-alkylation of the benzazaphosphole
derivatives (7a) and (18a) was readily achieved, and the interconversion of
2-oxides and 2-sulfides was accomplished by conventional methods.
The chemistry of lauren-1-ene. V. The structure of an acid-catalysed rearrangement product
Authors: Hanton LR , Simpson J , Weavers RT
Published: September 2010

The major product from the
formic-acid-induced rearrangement of lauren-1-ene has been confirmed to be (1S,4S,8R,9S,12R)-4,8,12,14,15-pentamethyltetracyclo[10,3,0,01,9,O4,9]pentadec-14-ene
by X-ray analysis of a derived diol.
The stereochemical assignment of the 1,2-Diphenylbut-3-en-1-ols, (1RS,2RS,3RS)- and (1RS,2RS,3SR)-3,4-Epoxy-1,2-diphenylbutan-1-ols and (2RS,3SR)- and (2RS,3RS)-3,4-Epoxy-1,2-diphenylbutan-1-ones and crystal structure of (1RS,2RS,3RS)-3,4-Epoxy-1,2-diphenylbutan-1-ol
Authors: Coxon JM , Simpson GW , Steel PJ , Trenerry VC
Published: September 2010

The reaction of the Grignard compound formed from
(E)-3-chloro-1-phenylprop-1-ene (2a) with benzaldehyde
has been studied and conditions found which allow for the efficient preparation
of the diastereoisomeric homoallylic alcohols (4) and
(5). The relative stereochemistry of these alcohols along with (1RS,2RS,3RS)-
and (1RS,2RS,3SR)-3,4-epoxy-1,2-diphenylbutan-1-ol (6) and (7) and (2RS,3SR)-
and (2RS,3RS)-3,4-epoxy-1,2-diphenylbutan-1-ones (8) and (10) has been
established and the crystal structure of (1RS,2RS,3RS)-3,4-epoxy-1,2-diphenylbutan-1-ol
determined.
The commercial agar from New Zealand Pterocladia species
Authors: Brasch DJ , Chuah C , Melton LD
Published: September 2010

The compositions of a
laboratory extracted agar and commercial agar prepared from a mixture of New
Zealand Pterocladia species (P. lucida and P. pinnata) are reported.
The structure of the commercial agar has been studied by using methylation
analysis, and the results, when considered along with the 13C n.m.r.
spectrum, show that the polysaccharide has a structure which is
close to that of agarose. Less than 1% of the agar is made up of 1,3-linked
6-O-methyl-D-galactopyranosyl residues. After complete acid hydrolysis, only 2%
of the total galactose obtained was the L-enan-tiomer. Reaction of the
Pterocladia agarose in the presence of the enzyme D-galactose oxidase showed
that the 1,3-linked D-galactosyl residues are oxidized even if they occur in an
ordered situation within the molecule.
Crystal structure of Hexakis(urea)chromium(III) hexacyanochromate(III) Bis(dimethyl sulfoxide) bis(ethano/)
Authors: Figgis BN , Kucharski ES , Patrick JM , White AH
Published: September 2010

The crystal structure of
the title compound, [Cr(OC(NH2)2)6] [Cr(CN)6].2(CH3)2SO.2CH3CH2OH,
has been determined from a single-crystal X-ray diffraction study at 295(1) K.
It was refined by least-squares methods to a residual of 0.039 for 4203
independent 'observed' reflections. Crystals are monoclinic, P21/n, a 17.449(6), b 10.315(4), c 11.726(3) �,
β 102.51(2)�, Z 2. Both chromium atoms lie on crystallographic centres of symmetry. Cr-O(urea) are 1.960(2),1.962(2),
1.982(1) � and Cr-C(cyanide) 2.074(2), 2.080(2), 2.081(2) �; the geometries of
the ligands and solvent molecules are correspondingly precise.
The relationship between carbon-13 substituent chemical shifts and proton coupling constants in aza-aromatic systems
Authors: Cook IB , Pengprecha S , Ternai B
Published: September 2010

An equation which relates
the ortho carbon-13 substituent
chemical shift α-SCS in aza-aromatics
to the ortho proton-proton coupling
constant 3J(HH) in the
corresponding carbocyclic compound is derived from
experimental data. The implications for N-N bond fixation in diaza-aromatics are discussed. When the equation is applied
to 2-substituted pyridines, an electronegativity parameter must be included to
explain the results.
Acylphosphonates as substrates for Wittig and Horner-Wittig reactions. Unusual stereoselectivity in the synthesis of β-phosphinoylacrylates
Authors: Harris RLN , Mcfadden HG
Published: September 2010

Phosphorus-stabilized
carbanions with additional stabilizing groups react with dialkyl
acylphos- phonates (alkanoyl-
and aroyl-phosphonates) to give fair to good yields
of dialkyl vinylphosphonates,
with some limitations imposed by competing side reactions of the acylphosphonates. β-Phosphinoyl-acrylates
prepared by the Wittig reaction were almost exclusively (E)-olefins, whereas
the corresponding Horner-Wittig reactions favoured (2) products. It is
suggested that electronic interactions of substituents in the reaction
intermediates play a role in determining this stereoselectivity.
cis-Aquachlorobis(ethane-1,2-diamine)ruthenium(III) trifluoromethanesulfonate: Crystal structure and hydrolysis kinetics
Authors: Hambley TW , Lawrance GA
Published: September 2010

The pale yellow
ruthenium(III) complex cis-[Ru(H2NCH2CH2NH2)2(OH2)Cl]
(CF3S03)2.H2O crystallized in the
space group P1, a 11.661(2), b 9.961(2), c 9.130(2) �, α 78.83(3), β70.42(2), γ 85.29(2)�, Z
2. The Ru-N, Ru-Cl and Ru-O bond distances in the essentially octahedral ion are
2.10 (average), 2.323(1) and 2.093(2) � respectively. The complex hydrolyses
with retention of configuration in aqueous acid (0.01 M HOSO2CF3,
kaq 2.70 x 10-5S-1
at 25�C, ∆H ? 90.6(� 1.5) kJ mol-1, ∆S ?-28 (� 5) 5 K-1
mol-1) and base (0.01 M NaOH, koh 0.44 mol-1 1. s-1 at 25�C,
∆H‡ 73.5(� 2.0) kJ mol-1, ∆S‡-43(� 7) JK-1 mol-1).
The Effect of Sorbates on the High-Resolution 29Si N.M.R. Spectra of Silicalite
Authors: West GW
Published: September 2010

The 29Si n.m.r.
spectrum from silicalite which consists of nine
specific peaks is changed substantially when ethanol, propan-1-ol, n-decane, or especially benzene is present in the channel
system.
Heterocyclic Tautomerism. The Solution and Crystal Structures of 1-(4',6'-Dimethylpyrimidin-2'-yl)-3-methylpyrazol-5-ol
Authors: Steel PJ , Whyte AR
Published: September 2010

Both in the solid state and
in solution, the title compound is shown to exist as the OH tautomer
(3), which is stabilized by a strong intramolecular hydrogen bond. Crystals of
the pyrazol-5-ol (3) are monoclinic: P 21/c, a 9.692(5), b 7.371(5), c 15.345(8) �, β 106.07(4)�, Z 4;
the structure was refined to R 0.072 and Rw
0.062.
Structural studies of polyhalogenated monoterpenes from Plocamium species
Authors: Capon RJ , Engelhardt LM , Ghisalberti EL , Jefferies PR , Patrick VA , White AH
Published: September 2010

Extraction of Plocamium mertensii and
an unclassified Plocamium
species found off the Western Australian coast yielded
(1R,2S,4S,1'E)-2-bromo-1-chloro-4-(2'-chloroethenyl)-1-methyl-5-methylenecyclohexane(3) and
(1R,2S,4R,5R,1'E)-4-bromo-1,2-dichloro-5-(2'-chloroethenyl)-1,5-dimethylcyclohexane
(4) respectively. The structures and absolute configurations were established
by single-crystal X-ray crystallographic structure determination.
The reaction of alkyllithium reagents with Furan-3-carboxylic acid. A synthesis of 4-(Furan-3'-yl)-1-methylbutyltriphenylphosphonium iodide
Authors: Dimitriadis E , Massy-Westropp RA
Published: September 2010

The ketones,
4-benzyloxy-1-(furan-3'-yl)pentan-1-one and 4-benzyloxy-1-(furan-3'-yl)butan-1-one,
have been prepared by generating the required alkyllithium
reagent in the presence of lithium furan-3-carboxylate. The latter ketone has
been transformed to 4-(furan-3'- yl)-1-methylbutyltri-phenylphosphonium
iodide.
New eudesmane sesquiterpenoids from Eremophila scoparia
Authors: Babidge PJ , Massy-Westropp RA
Published: September 2010

Three new eudesmane sesquiterpenoids have
been isolated from Eremophila scoparia. They are
(4aR,6S,7S,8aS)-7-hydroxy-6-(1-hydroxy-1-methylethyl)-4,8a-dimethyl-4a,5,6,7,8,8a-hexahydronaphthalen-2(1H)-one,
(4aS,6S,7S,8aS)-7-hydroxy - 6-(1 -hydroxy -1-methylethyl)-4,8a-dimethyl-4a,5,6,7,8,8a-hexahydronaphthalen-2(1H)-one
and (2S,3S,4aR,8aS)-3-(1-hydroxy-1-methylethyl)-5,8a-dimethyl-7-oxo-1,2,3,4,4a,7,8,8a-octahydronaphthalen-2-yl
acetate.
The Chemistry of Eremophila spp. XX. The Absolute Stereochemistry of the Viscidane Diterpenes
Authors: Ghisalberti E , Jefferies P , Mori T
Published: September 2010

Two new diterpenes have
been isolated from the resin of E. cuneifolia Kraenzlin and
interrelated with a known viscidane diterpene. The conversion of these diterpenes to the
sesquiterpene analogue,(–)-β-acoradiene, allows the absolute stereochemistry of the viscidane diterpenes to be defined.
The configurations of the trans-Camphane-2,3-diols
Authors: Angyal SJ , Craig DC , Tran TQ
Published: September 2010

The originally postulated
configurations of camphane-2-endo,3-exo- and -2-exo,3-endo-diols, which
were recently claimed to be incorrect, have been confirmed by the use of 13C
n.m.r. spectroscopy and by the X-ray crystal structure analysis of the dibenzoate of camphane-2-endo,3-exo-diol.
The kinetics of the electrodeposition of cadmium telluride
Authors: Danaher WJ , Lyons LE
Published: September 2010

The kinetics of the electrodeposition of CdTe from an aqueous solution containing CdSO4, TeO2
and H2SO4 were investigated by using a rotating ring-disc electrode. The results for tellurium
deposition alone indicated that the reaction occurs through a six-electron reduction of HTeO2+
to H2Te, followed by a reaction between H,2Te and HTeO2+ yielding tellurium. At HTeO2+
concentrations greater than 10-3 M, the second step of this process is very fast and the overall
reaction behaves as a four-electron reduction of HTeO2+ to Te: only at lower HTeO2+ concentrations
was evidence observed for the six-electron reduction. The electrodeposition of CdTe occurs through
two possible pathways: Cd2+ ions can react with H2Te produced during the reduction of HTeO2+
and thus yield CdTe, or tellurium deposited on the electrode can react with Cd2+ to yield CdTe.
The two reactions compete with the deposition of pure tellurium. Conditions to deposit stoichiometric
CdTe are suggested.
A structural, solvent exchange and spin equilibrium study of (N,N-dimethylformamide)(R,S,R,S)-(1,4,8,11-tetramethyl-l,4,8,11- tetraazacyclotetradecane)nickel(II)
Authors: Lincoln SF , Hambley TW , Pisaniello DL , Coates JH
Published: September 2010

The molecular structure of
R,S,R,S-[Ni {(-N(Me)(CH2)2N(Me)(CH2)3-)2}
(OCHNMe2)](SO3CF3)2 has been
determined in the solid state by X-ray diffraction methods. The geometry about
nickel(11) is midway between square based pyramidal and trigonal bipyramidal with OCHNMe2 occupying the axial or
an equatorial site in these geometries respectively. The nickel(II) is
displaced 0.29 � from the least-squares tetraaza
plane on the same side as the four methyl groups and OCHNMe2. In OCHNMe2
solution the formation of this five-coordinate high-spin species by
coordination of OCHNMe2 by its four-coordinate low-spin precursor is
characterized by K(298.2 K) = 10 � 2, ∆H = -12.8 � 2.7 kJ mol-1
and ∆S = -24.1 � 9.O JK-l mol-1 as determined by spectrophotometry. 1H (300 MHz) n.m.r. studies
show that kwx(298.2 K) = (1.6 � 0.2) × 107
s-1, ∆H‡ = 27.8 � 0.4 kJ mol-1 and ∆S‡ =
-13.O � 2.0 JK-1 mol-1 characterize the exchange of
OCHNMe2 on R,S,R,S-[Ni {(-N(Me)(CH2)2N(Me)(CH2)3-)2
}(OCHNMe2)]2+.
The crystal and molecular structure of the binuclear complex, (μ-Acetato-O,O')[(μ-S)-α,α'-{(2-mercapto-4-methylbenzene-1,3-diyl)di(methylidyne)di(azino)}bis(cyclohexanemethanol)ato(3 -)]dipalladium(II), LPd2(OAc), and its chloroform solvate, LPd2(OAc)(CHCl3)2
Authors: Hoskins BF , Mcdonald IAS
Published: September 2010

The crystal and nlolecular structures of the binuclear complexes LPd2(OAc), and its chloroform
solvate LPd2(OAc)(CHC/3)2, have been determined by single-crystal X-ray diffraction techniques.
These are the first reported structural analyses of binuclear complexes incorporating the quinquedentate ligand L3-, which is derived from the condensation of cyclohexanecarbohydrazide with
2-(N,N-dimethylthiocarbamato)-5-methylisophthalaldehyde. The three-atom acetate bridging group
is of special significance as all previous structure determinations of binuclear complexes containing
ligands similar to L3- have been restricted to those with either one or two-atom bridging groups.
LPd2(OAc) crystallizes in the triclinic space group P1 with a 15.513(1), b 22.238(2), c 8.0743(9) Ǻ,
α 100.81(1), β 99.54(1) and γ 77.23(1)°, whilst the solvate is monoclinic, P21/c, a 14.668(2), b
9.448(1), c 25.483(2) Ǻ and β 95.39(1)°.
Both structures were solved by the normal Fourier methods and refined by least-squares methods
which converged with R and Rw values of 0.044 and 0,051 for the 5084 independent, statistically
significant reflections collected for LPd2(OAc), and values of 0.063 and 0.066 for the 4883 reflections
collected for the solvate. Both structures are quite similar with the acetate group bridging palladium
centres which display similar distorted square-planar geometries, both within each molecule and
between molecules of different structures. The internuclear Pd-Pd distance, av. 3.68 Ǻ, is the longest
yet recorded for acetate-bridged, multinuclear palladium species and is attributed to the presence
of the bulky thiophenoxide hinge.
The essential difference between the two structures lies in the contrast between the near planarity
and approximate molecular mirror symmetry of the solvate compared with the less strained, asym-
metrical V-shape of the non-solvate. This difference has been attributed to the different packing
arrangement within the former, a consequence of the presence of the hydrogen-bonded solvent
molecules.
Crystal structure of Bis(8-hydroxyquinolinium) chloride tetrachloroferrate(III), a hydrogen chloride vapour pressure reference source?
Authors: Bottomley GA , Carter AM , Engelhardt LM , Lincoln FJ , Patrick JM , White AH
Published: September 2010

The crystal structure of
the title compound, [C9H8NO]2[FeCl4]C1,
has been determined by single-crystal X-ray diffraction methods at 295 K and
refined by least squares to a residual of 0.043 for 2415 independent 'observed'
reflections. Crystals are triclinic, P1, a
14.243(5), b 10.177(3), c 7.583(3) �, α 84.71(3), β
86.96(3), γ 86.50(3�, Z 2. The organic moiety is
protonated at the nitrogen atom, with the discrete chloride ions
hydrogen-bonded in lattice tunnels; this offers a rationale for the finite but
small hydrogen chloride partial pressure at room temperature.
Hydrolysis of 4-Nitro-2-(trifluoroacetylamino)benzoic acid: Buffer catalysis, micellar catalysis and intramolecular general acid catalysis
Authors: Broxton TJ
Published: September 2010

The hydrolysis of
4-nitro-2-(trifluoroacetylamino)benzoic acid was studied over the pH range
0-13. In strongly acidic solution (pH 0-3), intramolecular general acid
catalysis was observed. In alkaline solution, rate determining protonation of
the nitrogen atom of the intermediate complex formed by attack of hydroxide ion
on the substrate, was observed. The alkaline hydrolysis was subject to
significant micellar catalysis and this was accompanied by a change of
mechanism to solvent assisted C-N bond breaking. At intermediate pH (4-8), the
reaction was subject to significant buffer catalysis, and deprotonation of the
intermediate formed by the attack of water on the substrate was proposed.
Concerning the problem of the isokinetic relationship. II. The physical significance of the degrees of freedom in the statistical-mechanical model
Authors: Linert W , Kudrjawtsev AB
Published: September 2010

The statistical model
presented recently for the isokinetic relationship is
developed. The physical meaning of the degrees of freedom (s) is explained in
terms of ∆Cp‡, i.e. the change in the specific heat between
ground and activated states:
∆Cp‡ =-(s-1)R
In the case where (s-1)/(E/kBT) cannot be neglected the relationship is
∆Cp‡=-(s-1)(1-kBT/E)R
where E denotes the
potential barrier height. The results from a digital fitting procedure for the
complete form of the model are compared with those obtained from the simplified
equations for 'energy-barrier-controlled' reaction series.
Dihexadecyl phosphate vesicles: Permeability to cationic components in solar photolysis systems
Authors: Tricot Y , Furlong DN , Sasse WHF
Published: September 2010

Aqueous dihexadecyl
phosphate (dhp) vesicles prepared at pH 5.6-6.3, and
maintained at room temperature, retained ruthenium trisbipyridyl
(Ru(bpy)32+)
and methylviologen (mv2+) cations when
these species were entrapped during vesicle formation or by penetration of the
vesicle bilayer from aqueous solution. Increases in
pH, or heating to above 35�C, caused leakage of both Ru(bpy)32+ and mv2+ from
vesicles. Ry(bpy)32+
penetrated the vesicles at room temperature and pH 6.3 when the external
(non-adsorbed) Ru(bpy)32+
concentration was greater 10-4than mol dm-3. Penetration
of Ru(bpy)32+
occurred at lower concentrations if the pH was increased and/or the vesicles
were heated. The pH and heating conditions required to cause bilayer permeability towards mv2+ were more
severe than for Ru(bpy)32+
It is concluded that the bilayer is more able to
accommodate Ru(bpy)32+
and to permit its passage between the interior and exterior aqueous
environments.
The crystal and molecular structure of the binuclear complex [(μ-S)-α,α'-{(2-Mercapto-4-methylbenzene-1,3-diyl)di(methylidyne)di(azino)}bis(cyclohexanemethanol)ato(3 - )]-(μ-1-propylimidazolato-C(4),N(3))-dipalladium(II)-ethanol (1/0.75)
Authors: Hoskins BF , Mcdonald IAS
Published: September 2010

The crystal and molecular
structure of the 1-propylimidazolate bridged binuclear complex, LPd2(primid) has been determined by single-crystal X-ray
diffraction techniques at 20�C; disordered ethanol molecules are also present
in the lattice. The quinquedentate ligand L3-
is formally the trianion α,α'-{(2-mercapto-4-methylbenzene-1,3-diyl)di(methylidyne)di(azino)bis(cyclohexane-methanol)ato(3 -). Crystals of LPd2 (primid)
are triclinic, P1, with a 7.078(2), b l3.615(3), c 17365(3) �, α 78.52(2), β 80.21(2) and γ 83.83(2)�.
The structure was solved by conventional Fourier methods and refined by
full-matrix least-squares procedures to convergence with R and Rw 0.053 obtained for the 4133 statistically
significant structure amplitudes. The ligand sidearms are essentially
equivalent with both palladium centres displaying
similar distorted square-planar geometries, the separation being 3.605 �. The propylimidazolate bridging group is comfortably
accommodated within the binuclear framework and displays a geometry typical of
metal complexes of imidazole and its derivatives.
Coordination to the palladium centres occurs through
C4 and N3, a bridging mode not previously characterized by X-ray
crystallography, and one which illustrates the remarkable stability and flexibility
of the binuclear LPd2+ core.
Micellar catalysis of organic reactions. XIV. Hydrolysis of some 1,4-Benzodiazepin-2-one drugs in acidic solution
Authors: Broxton TJ , Ryan T , Morrison SR
Published: September 2010

Kinetic studies of the
acidic hydrolysis of diazepam and nitrazepam were
carried out in the presence of micelles of sodium dodecyl
sulfate (sds). The hydrolysis of diazepam was shown
to occur with biphasic kinetics. This is consistent with initial hydrolysis of
the azomethine bond followed by very slow hydrolysis
of the amide bond as found for hydrolysis in aqueous solution. Nitrazepam, however, was found to decompose with monophasic kinetics consistent with initial amide
hydrolysis. Reactions involving the hydrolysis of the azomethine
bond were shown to be independent of acid concentration and subject to
inhibition by micelles of sds. Reactions involving
amide hydrolysis were shown to be first order in acid concentration and subject
to micellar catalysis. The mechanistic change for the hydrolysis of nitrazepam on transfer from water (initial azomethine cleavage) to micelles of sds
(initial amide cleavage), was presumably the result of the inhibition of azomethine hydrolysis and the catalysis of amide hydrolysis
by the micelles.
The oxidative conversion of (E)-α-(Arylmethylene)benzeneacetates into substituted phenanthrenes: the propitious use of boron trifluoride with vanadium trifluoride oxide
Authors: Halton B , Maidment AI , Officer DL , Warnes JM
Published: September 2010

Vanadium trifluoride oxide (VOF3)/boron trifluoride diethyl etherate is
especially useful for effecting the cyclization of the (E)-α-(arylmethy1ene)benzeneacetates (4a,b,d) to the substituted phenanthrenes (5a,b,d). The products are obtained in 20%
higher yield and under milder conditions than by employing the vanadium reagent
with trifluoroacetic acid. A survey of the derivatives (4a-n) has shown that
oxygen functionality is necessary at the 3- and 4- and/or the 3'- and
4'-positions of (4) for cyclization to occur.
Nickel(II) and iron(II) complexes of 4-(Pyridin-2-yl)thiazole: Spectral, magnetic and structural studies
Authors: Baker AT , Goodwin HA , Rae AD
Published: September 2010

Iron(II) and nickel(II)
complexes of 4-(pyridin-2-yl)thiazole (L) have been
prepared. The electronic spectrum of [NiL3] [ClO2,]2
is similar to that of the corresponding complex of 2,2'-bipyridine (bpy) but indicates that the thiazole
provides the weaker field, the actual value of Dq(Ni2+)
being within the range which suggests the likely appearance of a spin
transition in iron(III). The iron(II)
complexes [FeL3] X2 (X = ClO4, BF4)
are, however, low-spin both in the solid state and in solution. The structure
of [NiL3] [ClO4]2.3H2O has been
determined, and this reveals a close similarity in the coordination environment
to that in [Ni(bpy),] SO4.7.5H2O.
The compound is monoclinic, space group P21/c, with four molecules
in a unit cell of dimensions a
9.404(4), b 29.169(8), c 17.900(8)ź, β 137.76(1)�. The
disordered structure was refined to a residual R 0.087 for 2307 observed
reflections. The pseudo-symmetric ligands are orientationally
disordered and one anion was also disordered. Restrained refinement with 194
parameters for 85 atomic positions produced a reliable geometry. The ligands
function as bidentates, giving the cation a distorted
octahedral structure.
Preparation and nuclear magnetic resonance studies of diaryloxytriphenylphosphoranes. Correlation of substituent effects with 31P N.M.R. chemical shifts
Authors: Itzstein Mv , Jenkins ID
Published: September 2010

Triphenylphosphine and diisopropyl azodicarboxylate
react with phenols in tetrahydrofuran or chloroform at 0° to give diaryloxytriphenylphosphoranes. A linear free-energy
relationship has been found between the 31P n.m.r. chemical shifts
of many of these phosphoranes and the acid
dissociation constants of the corresponding phenols. In general,
electron-withdrawing groups on the phenol result in downfield 31P
n.m.r. chemical shifts, while electron donating groups result in up-field
shifts.
Carbon-13 N.M.R. lanthanide-induced shift study of some D:A-friedooleananes
Authors: Wazeer MIM , Kumar V , Weeratunga G , Wijeratna DBT
Published: September 2010

Carbon-13 n.m.r. signal
assignments for D:A-friedooleanan-28-ol (1), D:A-friedooleanan-29-ol (2),
D:A-friedooleanan-30-ol (3)D:a-friedooleanan-30-ol (4, D:A-friedooleanan-21α-ol
(5) and 21α- hydroxy-D:A-friedooleanan-3-one (6) are reported.
Lanthanide-induced shifts of the hydroxy compounds indicate that the
oxygenation in the vicinity of ring E in these molecules does not affect the
chair-chair-chair-twistboat-boat conformation
proposed for D:A-friedooleananes.
Terpenoid Chemistry. XXVII. Further Iridoid Constituents, (1R)- and (1S)-1-Acetoxymyodesert-3-ene, from Myoporum deserti (Myoporaceae).
Authors: Grant HG , Russell-Maynard CA , Sutherland M.D.
Published: September 2010

A further chemovariety of Myoporum deserti A. Cunn . yields an
essential oil consisting predominantly of the iridoid hemiacetal esters, (+)-(1R)-and(-)-(1S)-1-acetoxymyodesert-3-ene. Hydrolysis of either ester yields (1S,2R,5R,1′ξ)-2-(1′-formylethyl)-5-methylcyclopentane-1-carbaldehyde and acetic acid or, in the presence of Brady's reagent, the bis-2,4-dinitrophenylhydrazone of the 1R-epimer. The stereochemistry at C1 of the esters follows from the close correlations in 1H and 13C n.m.r . spectra and o.r.d . curves of the (-)-ester and the ether (-)-(1R)-1-methoxymyodesert-3-ene. Hydrogenation of the esters in methanol yields mainly myodesertan , (4S)- myodesertan , (1R)-1- methoxymyodesertan and (1R, 4S)-1-methoxymyodesertan
and usually no acetates. Acetolysis of (1R)-1-methoxymyodesertan even under mild conditions yields (1R, 7aS)- and (1S, 7aS)-1-acetoxymyodesertan with trans rather than cis ring junctions.
The E.S.R. Spectra of Cation Radicals Derived from Phenethyltetrahydroisoquinoline Ethers and Model Compounds
Authors: Hewgill FR , Pass MC
Published: September 2010

Cation radicals derived from the title compounds by oxidation with thallium tristrifluoroacetate have been characterized. The structures assigned to these radicals suggest that initial oxidation occurs at the phenethyl ring in the compounds examined. Oxidation of homolaudanosine in this way gave the expected homoaporphine.
Initiation Mechanisms in Radical Polymerization: Reaction of t-Butoxy radicals with Allyl methacrylate
Authors: Busfield WK , Jenkins ID , Thang SH , Rizzardo E , Solomon DH
Published: September 2010

The radical-trapping technique employing 1,1,3,3-tetramethylisoindolin- 2-yloxyl (1) as scavenger has been used to study the reactions of t-butoxy radicals with allyl methacrylate
(2). Extensive hydrogen abstraction as well as addition to both allyl and acryloyl double bonds was observed. One unusual feature of the reaction, the formation of considerably more (Z)- alkene than (E)- alkene from trapping of radicals derived from the allyloxy moiety, is also discussed.
Reactions of Stenhouse Salts. III. Transformation Products Under Acidic and Basic Conditions
Authors: D'Arcy BR , Lewis KG , Mulquiney CE
Published: September 2010

Mild acid treatment of alcoholic solutions of Stenhouse salts has been shown to yield a mixture of the corresponding N-arylpyrrole-2-carbaldehyde and the N-aryl-3-hydroxypyridinium salt. Treatment of alcoholic solutions of the Stenhouse salts with a variety of bases leads to 4-substituted 2-arylaminocyclopent-2-enones.
The Attachment of Low-Energy Electrons to Dicyanogen in the Gas Phase
Authors: Harland PW , McIntosh BJ
Published: September 2010

The negative ions C-, CN- and C2N- formed by the dissociative resonance attachment of low-energy electrons to dicyanogen in the gas phase have been studied over the electron impact energy range from 0 to 15 eV. The formation of the CN- ion was studied by using a 'monochromatic' electron gun and the translational energy of the ion measured as a function of the electron energy across the dissociative resonance capture curve. An energy balance analysis for CN- ion formation has been used to propose the electron capture processes and to construct a potential energy diagram (for C-C internuclear separation) for CN- ion formation. The molecular ion, C2N2-, has been shown to result from the associative resonance attachment of thermalized electrons scattered from the collision chamber surfaces and to exhibit an autodetachment lifetime in the microsecond timerange.
3,4,5,6,7,8-Hexahydro-1,7-benzodiazecin-2(1H)-one from Extracts of Mackinlaya Species
Authors: Johns SR , Lamberton JA , Suares H
Published: September 2010

A minor base from Mackinlaya macrosciadia (F. Muell ) F. Muell has been shown to be 3,4,5,6,7,8-hexahydro-1,7-benzodiazecin-2(1H)-one. This compound is formed in low yield from decomposition of 6,7,8,9- tetrahydro-11H-pyrido[2,1-b]quinazoline, the major base, on storage, and it is conveniently prepared by hydrolysis of the major base in water.
Dialkylhydroxylamido(1—)-O,N Complexes of Tungsten(VI) with Terminal Oxo and Thio Ligands
Authors: McDonell AC , Vasudevan SG , O'Conner MJ , Wedd AG
Published: September 2010

The compounds cis -[WO2(R2NO)2] (R = Et,
PhCH2, �C5H10) have been synthesized by the
reaction of WO2Cl2 or [WO2(C5H7O2)2] with the respective N,N- dialkylhydroxylamines in the presence of Et3N. When heated with WO2Cl2 in refluxing MeCN , Et2NOH undergoes dealkylation and MeCN insertion to produce cis -[WO2(NH(Me)CN(Et)O)2] which features the bidentate N-ethyl-N- hydroxyacetamidinato (1-)-O,N′ ligand . cis - [WS2(R2NO)2] and cis -[WOS(C5H10NO)2] can be isolated in satisfactory yields by the reaction of [WO2(R2NO)2] with B2S3. The new compounds have been characterized by microanalysis, by infrared and elecronic spectroscopy and by 1H, 13C and 183W n.m.r.
Pyrolysis of Aryl Azides. VI. Identification of Neighbouring Group Effects in Pyrolysis of Azidopyridines and Azidoquinolines
Authors: Dyall LK , Wah WM
Published: September 2010

Although there are literature reports of anomalous behaviour on pyrolysis of ortho-nitroazido-pyridines and ortho-nitroazidoquinolines, we find that these compounds cyclize to the expected furazan 1-oxides in near-quantitative yields, and with a high degree of neighbouring group participation by the nitro group. Kinetic studies in decalin solution reveal the following rate enhancements by the ortho-nitro group: 3-azido-2-nitropyridine, 466 at least; 4-azido-3-nitropyridine, 5400; 4-azido-3,5-dinitropyridine, 640; 4-azido-3-nitroquinoline, 82.4; 5-azido-6-nitroquinoline, 27.6; 2-nitro-1-azidonaphthalene, 12.7. The unstable furazan oxide, [1,2,5] oxa-diazolo [3,4-c]pyridine 1-oxide, has now been characterized. [1,2,5] Oxadiazolo [3,4-b]pyridine 1-oxide decomposed in decalin at 145° to give products indicative of a nitrene intermediate.
Activation Volumes for Acid Aquation of Iron(II) Complexes of Alkyl-Substituted Bipyridine and Methanol Solvolysis of Tris(phenanthroline)iron(II)
Authors: Lawrance GA
Published: September 2010

The aquation of Fe(R2C10H6N2)32+ (R2C10H6N2 = disubstituted 2,2′-bipyridine) was studied in aqueous acid at a range of pressures between 1 and 1380 bar. Activation volumes (Δ V‡) in 1.0 and 0.01 M HCl respectively were + 12.5(�0.7) and + 15.5(�0.5) cm3 mol-1 for R2 = 4,4′-dimethyl, + 12.7(�0.6) and + 16.9(�0.6) cm3 mol-1 for R2 = 4,4′-diethyl, and + 13.7(�0.5) and + 17.4(�0.8) cm3 mol-1 for R2 = 5,5′-dimethyl. The methanol solvolysis of Fe( phen )32+ ( phen = 1,10-phenanthroline) in the presence of 0.1 M HOSO2CF3 yielded Δ H‡ 120(�2) kJ mol-1, ΔS‡ +72(�5) J K-1 mol-1 and Δ V‡ + 14.1(�0.2) cm3 mol-1. The Δ V‡ values differ little for a range of unsubstituted and substituted bipyridine and phenanthroline complexes of iron(II), nor does the value for Fe( phen )32+ vary with solvent. These observations are further evidence for a mechanism involving a significant positive contribution to Δ V‡ from a low-spin ↔ high-spin preequilibrium operating.
Reaction of Aryltrialkylstannanes with Lead Tetraacetate: a Convenient Route to Aryllead Triacetates
Authors: Kozyrod RP , Morgan J , Pinhey JT
Published: September 2010

A study of the reactions of o- methoxyphenyltrimethylstannane and o- methoxyphenyltributylstannane with lead tetraacetate has been carried out. This has led to the development of a new high-yielding
route to aryllead triacetates, which involves the treatment of an aryltributylstannane with lead tetraacetate and a catalytic amount of a mercury(II) compound in chloroform. The reaction has been shown to be quite general, giving good results with electron-rich and electron-deficient aromatics.
Preparation of some 2-(2'H-Benzotriazol-2'-yl)phenol ultraviolet absorbers: application of the transalkylation reaction
Authors: Rosevear J , Wilshire JFK
Published: September 2010

When
2-(2′H-benzotriazol-2′-yl)phenols containing t-alkyl substituents are warmed in toluene solution with an aluminium chloride/ nitromethane catalyst, the t-alkyl groups are transferred to the solvent (toluene). This transalkylation reaction has been used to prepare not readily accessible or previously inaccessible 2-(2′H-benzotriazol-2′- yl )phenols, a class of ultraviolet absorbers widely used in industry.
New Tricyclic Diterpenes from the Sponge Higginsia sp
Authors: Cassidy MP , Ghisalberti EL , Jefferies PR , Skelton BW , White AH
Published: September 2010

The structure of a new tricyclic diterpene (1) isolated from an unclassified Higginsia sp. has been determined by X-ray crystallographic methods. The structures of two related co-metabolites have been deduced from a comparison of their spectroscopic properties with those of (1).
Eremophilane and Serrulatane Terpenoids from Eremophila rotundifolia
Authors: Adell AD , Massy-Westropp RA
Published: September 2010

The new terpenoids, 9-oxoeremophila-10,11(13)-dien-12-al (3) and 5,8- dihydroxyserrulat-14-en-18-al (2) have been isolated and their absolute stereochemistry established by chemical correlation with known compounds.
Preparation and Spectroscopic Properties of Cyclohexyneplatinum(0) Complexes Containing Ditertiary Arylphosphines and of Their Protonation Products
Authors: Bennett MA , Rokicki A
Published: September 2010

Cyclohexyneplatinum (0) complexes Pt(C6H8)(P~P) [P~P = (Z)-Ph2PCH=CHPPh2, Ph2P(CH2)3- PPh2 or Ph2P(CH2)4PPh2] and Pt(C6H8)(PMePh2)2 have been prepared by displacement of tri- phenylphosphine from Pt(C6H8)(PPh3)2. Like the known compound containing Ph2PCH2CH2PPh2, these complexes are readily protonated by both strong and weak acids (HY) to give η1-cyclohexen-1- yl -platinum(II) complexes PtY (C6H9)(P~P)
(Y = Cl , SPh , O2CMe, CH2CN, OMe , OH). An excess of HCl rapidly cleaves the Pt-C6H9 bond giving PtCl2(P~P) complexes identical with those made from PtCl2(cycloocta-1,5-diene) and P~P. The methoxo complexes react rapidly with water to give the hydroxo complexes and with CO to give methoxycarbonyl complexes Pt(CO2Me)(C6H9)- (P~P). The i.r ., 1H and 31P{1H} n.m.r . spectra of the new complexes are reported and trends in the 31P chemical shifts ( δP ) and in the 195Pt-31P coupling constants (1JPt,P) are compared with those reported in the literature for related systems.
The Molecular Geometry of Diastereoisomeric Bis[α-(9-anthryl)ethyl] Ethers
Authors: Becker H , Patrick VA , Skelton BW , White AH
Published: September 2010

The crystal structures of racemic bis [α-(9-anthryl)]
ether and its meso form have been determined by single-crystal X-ray diffraction methods at 295 K, being refined by least squares to residuals of 0.053 and 0.041 for 1868 and 3568 independent 'observed' reflections respectively. Crystals of the racemate are orthorhombic, Pcab, a 23.07(1), b 19.85(2), c 10.241(8) Ǻ, Z 8. Crystals of the meso form are triclinic, Pī , a 19.032(12), b 14.207(11), c 9.451(8) Ǻ, α 79.46(6), β 89.68(6), γ 68.97(5)°, Z 4. In the racemate , the dihedral angle between the methyl groups along the ether bonds is 12°, and the short axes of the anthracene moieties lie at an angle of about 120°. In the meso compound, for the two molecules the dihedral angles between the methyl groups along the ether bonds are 90 and 93°, the angle between the two anthracene moieties is 90°, and the interplanar angles between the partly overlapping aromatic systems are 46 and 43°.
Complexes of Muellitol [1,3,5-Tri(3-methylbut-2-enyl)-scyllo-inositol] with Metal Cations
Authors: Angyal SJ , Greeves D , Littlemore L
Published: September 2010

Complex formation of muellitol with dipositive cations is fast, with tripositive cations slow, on the n.m.r . time-scale. The lanthanide- induced shifts of the signals in the 1H and 13C n.m.r . spectra of these complexes vary greatly, in sign and magnitude, with the nature of the solvent.
The Structure of a Stable Serrulatane Diterpenoid Acetal From Eremophila-Rotundifolia
Authors: Abell AD , Horn E , Jones GP , Snow MR , Massywestropp RA , Riccio R
Published: September 2010

The serrulatenol (1a), a stable diterpenoid acetal from remophilia rotundifolia, has been shown to be (13S,18R)-5,18:13,18- diepoxyserrulat-14-en-8-ol by chemical and spectroscopic characterization and by single-crystal X-ray analysis of the p- bromobenzoate . This compound crystallizes as clear prisms in the monoclinic space group P21 with a 9.112(1), b 9.743(2), c 13.423(3) Ǻ, β 102.27(5)° and Z 2. The
structural final refinement of a blocked-matrix least-squares calculation converged with R 0.038 and Rw 0.041.
Synthesis and Characterization of 2-Iodo-4-[5′-(4'″-Methylpiperazin-1'″-yl)-2′,5′-bi-1h-Benzimidazol-2 ′-Yl]Phenol (iodoHoechst 33258) and 2,5-Disubstituted Benzimidazole Model Compounds
Authors: Martin RF , Pardee M , Kelly DP , Mack POL
Published: September 2010

The product of iodination
of the DNA-binding dye Hoechst 33258,4-[5′-
(4′′′-methylpiperazin-1′′′-yl)-2′,5′-bi-1H-benzimidazol-2′-yl]phenol (1), has been identified as the monoiodo derivative, i.e. 2-iodo-4-[5′- (4′′′-methylpiperazin-1′′′-yl)-2′,5′-bi-1H-benzimidazol-2′-yl]phenol (2), by mass spectrometry and by comparison of the 1H and 13C n.m.r . spectra of (1) and (2) with those of 2,5-disubstituted benzimidazole model compounds (3) and (4).
Metal-Complexes of Thiocholinate, -SCH2CH2Nme3+. I. Preparation and Crystal-Structure of Pentakis(Thiocholinato)Dilead(II) Hexafluorophosphate
Authors: Dance IG , Guerney PJ , Rae AD , Scudder ML , Baker AT
Published: September 2010

Aqueous solutions containing lead(II) and deprotonated thiocholine contain water-soluble homoleptic lead thiolates , which crystallize as yellow needles of [Pb2(SCH2CH2NMe3)5] (PF6)4 in the presence of PF6-, but crystallize [ Pb (SCH2CH2NMe3)2](ClO4)2 with 1 : 2 stoichiometry in the presence of ClO4-. Crystalline [Pb2(SCH2CH2NMe3)5](PF6)4 contains almost linear chains composed of end-linked {(SR)2Pb(μ-SR) Pb (SR)2} coordination units, within which the primary Pb -S coordination (mean 2.73 Ǻ, sample e.s.d . 0.10 Ǻ) is orthogonal trigonal (S- Pb -S, mean 88.9°, sample e.s.d .3.7°) at each lead atom. Within the {Pb2(SR)5} unit there is one double bridge with two rimary bonds, and one double bridge involving one secondary Pb --S connection (mean 3.23 Ǻ, sample e.s.d . 0.12 Ǻ). Three double-bridges involving secondary Pb --S coordination link the ends of the dimetallic units, and consequently bis - and tris -double thiolate bridges alternate along the chain. Overall coordination at each lead atom is pseudo-octahedral, with one non-bonding electron pair and two cis secondary Pb --S bonds. The cationic tails of the ligands radiate from the chains into a matrix of PF6- ions, and the chains are approximately hexagonally close-packed with a separation of 14.4 Ǻ. Along the b axis there are homogeneous stacks of the ammonium functions, the anions, and the Pb, S chains, with a pseudo-symmetric repeat of b/3 in each stack, allowing disorder due to stacking faults. This disorder has been adequately modelled in the refinement, which also incorporated back-Fourier-transform techniques to avoid inaccuracies due to spherically disordered PF6- ions. Crystal data: Cc, 25.535(8), b 43.13(1), c 15.123(5)Ǻ, β 100.36(9)°, Z 12 (× Pb2S5C25H65N5P4F24), 3585 observed data, R 0.066.
The Vibrational-Spectrum of Sodium Propionate CH3CH2CO2Na, CH3CD2CO2Na, CD3CH2CO2Na and CD3CD2CO2Na in Aqueous-Solution and in the Solid-State
Authors: Spinner E , Yang P , Wong PTT , Mantsch HH
Published: September 2010

Infrared absorption spectra of aqueous solutions and KBr discs, reflection spectra of the diluted powders and of an oriented thin film, and Raman spectra of the powdered solids have been measured for CH3CH2CO2Na, CH3CD2CO2Na, CD3CH2CO2Na and CD3CD2CO2Na. Selective deuteration makes possible complete vibrational assignments in the CH and CD stretching regions where band overlap is extensive, but produces complicated changes in 1200- 800 cm-1 range. Average methyl CH stretching frequencies are higher in propionate ion than in paraffins in spite of the interposed methylene group. In the solids the CO stretching vibrations show more frequency splittings than expected for the number of molecules per unit cell (2), and some orientational disorder is indicated. The shape of the anions was not established; there is no evidence indicating the presence of more than one conformation in solution.
An X-Ray Crystallographic Study of Cd[P(C-C6H11)3]2(NO3)2.CH2Cl2
Authors: Dakternieks D , Hoskins BF , Rolls CL , Tiekink ERT
Published: September 2010

The crystal and molecular structure of bis ( tricyclohexylphosphine )cadmium(II) nitrate as its dichloromethane solvate, Cd [P(c-C6H11)3]2(NO3)2.CH2Cl2, has been determined by single- crystal, three-dimensional X-ray diffraction methods. The crystals of the cadmium(II) complex are monoclinic with space group C2/c, a 20.880(6), b 12.775(3), c 17.075(5) Ǻ and β 106.38(2)°, Z 4. The structure was solved by normal Fourier methods and refined by a full-matrix least-squares procedure. The refinement used the 2169 statistically independent reflections for which I ≥ 2σ(I) converged with R and Rw of 0.065 and 0.067 respectively. The crystals consist of discrete Cd [P(c-C6H11)3]2(NO3)2 molecules and CH2Cl2 in the ratio 1 : 1. There is a distorted tetrahedral environment around the cadmium atom formed from the coordination of the two phosphines and two nitrates with each nitrate essentially occupying one stereochemical position. The two markedly different Cd -O bond lengths of 2.405(9) and 2.575(8) Ǻ show gross asymmetry in the coordination of the nitrate.