bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of the radical scavenger 1,1,3,3-Tetramethylisoindolin-2-yloxyl
Authors: Griffiths PG , Moad G , Rizzardo E
Published: September 2010

A versatile free-radical
trapping agent, 1,1,3,3-tetramethylisoindolin-2-yloxyl, has been prepared from
N-benzylphthalimide by reaction with 'methylmagnesium iodide' in refluxing toluene followed by
hydrogenolysis and oxidation. The Grignard reaction
gives 2-benzyl-1,1,3,3-tetramethylisoindoline along with a small proportion of
an unexpected by-product, 2-benzyl-1-ethyl-1,3,3-trimethyliso-indoline.
Synthesis of Methyl-5,6,11,12-tetrahydrodibenzo[a,e]cyclooctenols and a conformational study by proton nuclear magnetic resonance
Authors: White KE , Slater BJ , Graham SH
Published: September 2010

A series of
methyl-5,6,11,12-tetrahydrodibenzo[a,e]cycloocten-5-ols were synthesized, and their
conformations assigned by means of proton nuclear magnetic resonance. Placing
substituents in three of the four available sites on the eight-membered ring
enabled the chemical shifts of the geminal proton to
be observed. It was found that the three sites have intrinsic chemical shifts.
The compounds studied were found to populate a twist-boat conformation, with
bulky substituents preferentially populating the axial site.
The preparation and photolysis of (E)-1-Aryl-3-methyl-3-phenylbut-1-enes
Authors: Blunt JW , Coxon JM , Robinson WT , Schuyt HA
Published: September 2010

Reaction of
2-methyl-2-phenylpropylmagnesium chloride with benzaldehyde in tetrahydrofuran gave
2,7-dimethyl-2,4,5,7-tetraphenyloctane-4,5-diol as a 1 : 2 mixture of clear
transparent crystalline plates (meso) and needles (�), 3-methyl-1,3-diphenylbutan-1-one,
benzyl alcohol, 2-methyl-2-phenylpropaneand a low yield of
3-methyl-1,3-diphenylbutan-1-ol. The distinction between the meso and the
(+)- diols was unequivocal because the unique space
group of the former requires thedimeric molecules to
lie about a crystallographic centre of symmetry. The mechanism involved in the
formation of the products of the Grignard reaction is
examined. By careful choice of reaction conditions a series of
I-aryl-3-methyl-3-phenylbutan-1-ols were prepared. Dehydration of the 1-aryl-3-methyl-3-phenylbutan-1-ols
with p-toluene sulfonic acid and a short reaction
time gives(E)-1-aryl-3-methyl-3-phenylbut-1-enes but longer reaction times
afford 3-aryl-1,1-dimethylindanes.Photolysis of the
(E)-1-aryl-3-methyl-3-phenylbut-1-enes affords
(Z)-1-aryl-3-methyl-3-phenylbut-1-enes and
trans-1-aryl-3,3-dimethyl-2-phenylcyclopropanes. Extended photolysis gives
4-aryl-2-methyl-3-phenylbut-1-enes via
trans-1-aryl-3,3-dimethyl-2-phenylcyclopropane by rupture of the cyclopropyl bond adjacent to the aryl substituent.
f-f spectral studies of holmium(III) complexes
Authors: Iftikhar K , Ahmad N
Published: September 2010

Holmium(III) mixed-ligand
complexes containing ligands having oxygen and nitrogen donors have been
spectrophotometrically investigated. The observed spectra in the visible region
have been analysed to calculate covalency parameters (β, b� and
δ), oscillator strengths and Judd-Ofelt parameters. The degree of
covalency in the complexes increases with increase in coordination number. The
hypersensitivity is correlated with the degree of covalency and number of
coordinated ligands. The higher values of covalency parameters, oscillator
strength and magnetic moment in the ten-coordinate HoIII is taken as
evidence of participation of f-orbitals in bonding.
Amine autoxidation in aqueous solution
Authors: Beckwith ALJ , Eichinger PH , Mooney BA , Prager RH
Published: September 2010

The uncatalysed
autoxidation of aqueous solutions of tertiary aliphatic amines has been studied
in order to obtain information concerning the mechanism of oxidation of
Sirotherm resins. Oxidation occurs most rapidly in the free base, and the
general correlation of rate with pK, or ionization potential suggests that
electron transfer to form an aminium radical cation is rate-determining. The
reaction is not initiated by free radical initiators, nor inhibited by radical
traps. It is significantly catalysed by strong electron acceptors and by light
and is moderately inhibited by the electron donor N-phenylanthranilic acid.
Pyrrolidines and hexahydroazepines are oxidized faster than piperidines, and
hydroxyl groups on β-carbons increase the rate of oxidation, while those on
γ-carbons decrease it. The major products of autoxidation of alkyl pyrrolidines
in water were found to be N-oxides. Various pyrrolidinones were isolated in
smaller yield.
The pyrrolizidine alkaloids of Amsinckia menziesii
Authors: Roitman JN
Published: September 2010

Methanolic extracts of
fresh Arnsinckia menziesii (Lehm.) Nels, and Macbr. (Boraginaceae) yielded
three known pyrrolizidine alkaloids, intermedinet (I), lycopsaminet (2) and
7-acetyllycopsaminet (3). In addition, two new alkaloids were isolated and
shown to be 9-[(2'S,3'S)-3'-acetoxy-2'-hydroxy-
2'-isopropylbutanoyl]retronecine,t (3'-acetyllycopsamine) (4) and
7-acetoxy-9-[(2'S,3'S)-3'-acetoxy- 2'-hydroxy-2'-isopropylbutanoyl]retronecine,
(3',7-diacetyllycopsamine) (5). Structures of all of the alkaloids were
determined by means of mass spectrometry and 13C and 1H n.m.r. spectroscopy.
The structures of the new alkaloids were confirmed by acetylation of
lycopsamine (2) to give 3'-acetyl- lycopsamine (4) and 3',7-diacetyllycopsamine
(5).
Some base-catalysed reactions of polysubstituted Cyclohexa-2,5-dienones
Authors: Hartshorn MP , Martyn RJ , Vaughan J , Wright GJ
Published: September 2010

Substituted
4-nitrocyclohexa-2,5-dienones (la), (lb) and (4a) give
6-hydroxycyclohexa-2,4-dienones on mild treatment with aqueous sodium
bicarbonate. Reactions of cyclohexa-2,5-dienones (4a) and (5) with ammonia in
ether give phenols (7a) and (7b) with the loss of bromine from C4. The
preparations of the 4-nitro dienones (4a) and (4b) are described.
Quinoline Alkaloids From the Heartwood of Balfourodendron riedelianum
Authors: Jurd L , Wong R
Published: September 2010

The principal alkaloid of Balfourodendron riedelianum (Rutaceae) has been isolated and identified as (+)-ribaline (1b). The heartwood also contains minor amounts of
(�)-ribaline and of two new alkaloids, identified as
(+)-ribalinidine (2b) and (+)-2-(1'-hydroxy-1'-methylethyl)-2,3-dihydrofuro-[2,3-b]quinolin-6-ol [(+)-riedelianine] (4) by spectroscopic and X-ray
crystallographic measurements.
The spectrophotometric solvent sorting method for the determination of free energies of transfer of individual ions—a critical appraisal
Authors: Wells CF
Published: September 2010

The spectrophotometric
method for determining values for the free energy of transfer of the proton from
water into water + co-solvent mixtures at mole fractions of co-solvent up to x2
≈ 0.3 is examined critically from first principles. It is found that some
corrections become significant at the higher x2 in this range and
these are applied to all the co-solvents used. The new values for ΔGt�(H+) are then used to calculate new
values for ΔGt� (X-) from ΔGt�(HX) and new values for ΔGt�(M+) and (M2+)from ΔGt�(MX) and ΔGT�(MX2). New electrochemical,
solubility and pK data are incorporated into these
calculations, resulting in ΔGt�
values for some additional ions for several co-solvents. The ΔGt� values for all co-solvents are
compared and contrasted, and it is concluded that structural changes in the
solvent have a dominant effect in determining these values. The evidence for
molecular rearrangements involving solvent molecules in the neighbourhood
of the ions resulting from the transfer is examined.
Thermodynamics and structures in solvents coordinating through nitrogen. I. Enthalpies of transfer from water to pyridine and acetonitrile for some monovalent cations and anions
Authors: Ahrland S , Ishiguro S , Portanova R
Published: September 2010

The enthalpies of transfer ΔHtr�, between water and the aprotic
solvents pyridine and acetonitrile have been
determined for a number of 1-1 electrolytes. To calculate ΔHtr�
for the single ions, the tatb assumption that ΔHtr�,(Ph4As+) = ΔHtr�BPh4-)
for all solvents has been applied. The results are compared with those found
earlier for the transfer between water and dimethyl sulfoxide. The values of ΔHtr�, differ widely between different
ions, from exothermic by c. 30 kJ/mol to endothermic by about the same amount.
Endothermic values are found for Cl- and, though much smaller, for Br-, and
also for the large tetraalkylammonium ion Bu4N+.
Compared to the differences in ΔHtr�,
found between the various ions, the differences found for a certain ion between
different solvents are small. The decrease of AH,", in the sequence Cl-
> Br- > I- runs almost parallel in the three aprotic solvents, and is
much less steep than in water. This reflects the influence of ligand hydrogen
bonding in the protic solvent.
The chemical reactivity and molecular structure of 4,6-Dinitro-2-(2,4,6-trinitrophenyl) benzotriazole 1-oxide. A new heterocyclic super-electrophile
Authors: Renfrow RA , Strauss MJ , Cohan S , Buncel E
Published: September 2010

The first preparation of
the title compound (3) is reported and its reactivity with nucleophiles examined.
Attack occurs at both the benzotriazole and the picryl ring moieties, the former process giving rise to
spectrally observable Meisenheimer type σ-complexes, the latter to
displacement. The results allow comparison to be drawn with the behaviour of
4,6-dinitrobenzofuroxan, which also acts as a super-electrophile. The structure
of (3) has been determined from three-dimensional X-ray data collected from a
single crystal. The material crystallized in space group Pbca of the orthorhombic system
with eight molecules in a cell of dimensions
a 16.050, b 11.478, c 17.823 A; V 3283.5 �3.
The stereochemistry of organometallic compounds. XXIV. Nickel(0)-catalysed additions of hydrogen cyanide to alkynes
Authors: Jackson WR , Lovel CG
Published: September 2010

Hydrogen cyanide will add to alkynes bearing a wide range of substituents with cis stereospecificity,
high regioselectivity, and in moderate-to-good yields, when the reaction is catalysed by tetrakis-
(triphenyl phosphite)nickel(0).
The application of the Hammett equation to 13C N.M.R. spectrometry. VI. Remote ring effects in azobenzenes and stilbenes
Authors: Christoforou D , Happer DAR
Published: September 2010

The 13C n.m.r. chemical shifts for the non-substituted rings of azobenzene, stilbene, 26 monosubstituted
azobenzenes and 28 monosubstituted stilbenes are reported. The effects of substituents
in one ring on the chemical shifts of the other have been interpreted in terms of their inductive and
resonance effects by means of a dual substituent parameter analysis. The results show that inductive
effects are transmitted to the remote ring from the meta and para positions with equal efficiencies
and polarize the phenyl group independently of the rest of the molecule. Resonance interaction is
greatest when the substituent is para to the azo or vinylene linking group and is relayed with greatest
efficiency to the ortho and para carbons of the remote ring. The results of the study are compared
with previously unreported data for the corresponding ring carbons of the ethyl arylazo- and
arylethenyl-cinnamates, and with literature data on para-substituted biphenyls and terphenyls.
Reactions of methyl radicals. V. Hydrogen abstraction from hydrogen sulfide
Authors: Arican H , Arthur NL
Published: September 2010

Hydrogen abstraction from H2S
by CH3 radicals, produced by the photolysis of azomethane, has been studied in the temperature range
334-432 K. The rate constant, based on the value 1013.34 cm3
mol-1 s-1 for the recombination of CH3
radicals, is given by
log k4 = (11.00 � 0.01) - (8760 �
80)/19.145T
where k4 is
in cm3 mol-1 s-1 and E is in J mol-1.
The previous data reported for this reaction are discussed and
best values for its Arrhenius parameters are
recommended. The results indicate that CH3 radicals react faster
than CF3 radicals with H2S;
this confirms the importance of polar effects in the hydrogen
abstraction reactions of CF3
radicals.
Studies of Australian soft corals. XXXII. The structure determination of degraded xenicin-type diterpenes from several Efflatounaria species
Authors: Bowden BF , Coll JC , Patrick VA , Tapiolas DM
Published: September 2010

Three new diterpenes have
been isolated from soft corals of the genus Efflatounaria (Coelenterata, Octocorallia, Alcyonacea, Xeniidae). The
structure of the first compound (4) was elucidated on the basis of high-field 1H
n.m.r. spectroscopy while that of the second metabolite (5) was determined by
single-crystal X-ray analysis. The third diterpene
(6) was structurally related to (5), and its structure was confirmed by
chemical transformation. All three diterpenes can be derived from xenicin-type precursors, by cleavage and recyclization.
Kinetic studies on the imines derived from reaction of 2-Amino-2-hydroxymethylpropane-1,3-diol with 2-Hydroxybenzaldehyde and with 1-Hydroxy-2-naphthaldehyde. Hydrolysis kinetics, and evidence for catalysis by the phenolate (ortho-O-) group in the imine formation reaction
Authors: Singh RMB , Main L
Published: September 2010

pH-rate profiles are
reported for the hydrolysis of 2-[[{2-hydroxy-1,1-di(hydroxymethyl)ethyl}-imino]methyl]phenol
(1) and 1-[[{2-hydroxy-1,1-di(hydroxymethyl)ethyl}imino]methyl]-2-naphthol
(2). Rate coefficients for possible contributing reactions are established and
compared. Measurement of the rate of hydrolysis in deuterium oxide of (1) in
the neutral plateau region of the pH-rate profile shows that the imine (1) is about 1.6 times more reactive in H2O
than in D2O, and possible contributing factors to this solvent
isotope effect are considered. Also reported are rate data for formation of (1)
from 2-amino-2-hydroxymethylpropane-1,3-diol and 2-hydroxybenzaldehyde which
show the latter to be almost as reactive in the anionic as in the neutral form;
this suggests a base catalysis role by the phenolate oxygen in imine formation.
Structure of the corynetoxins, metabolites of Corynebacterium rathayi responsible for toxicity of annual ryegrass (Lolium rigidum) pastures
Authors: Frahn JL , Edgar JA , Jones AJ , Cockrum PA , Anderton NA , Culvenor CCJ
Published: September 2010

The corynetoxins,
toxic metabolities of Corynebacterium rathayi
formed in galled seed-heads of infected annual ryegrass, Lolium rigidum, are shown to be new members of the tunicamycin
group of antibiotics. They consist of N-acetylglucosaminyl-tunicaminyl-uracil
in amide linkage with fatty acids which differ in certain respects from those
present in the tunicamycins. The corynetoxin acids
are of slightly longer chain length, C15-C19, occur in a β-hydroxy
as well as saturated and α,β-un-saturated series, and have anteiso, iso and normal chain
terminations. β-Hydroxy acids have not been observed previously in the
tunicamycin group and anteiso chains were reported
only recently in the streptovirudin subgroup.
Stereochemical identity of the C11-aminosugar
in the corynetoxins with the tunicamine
part of the tunicamycins is demonstrated by formation
of a common hydrolysis product, di(N-trifluoro-
acetyl)glucosaminyl-tunicaminyl-uracil. Analysis of
the carbon-13 and proton n.m.r. spectra of the main components, corynetoxins H17a and U17a, confirms the stereochemistry
proposed for tunicamine except that the glycosidic
linkages are changed to α-galactosamine, β-glucosamine.
Chemistry of the Podocarpaceae. LXVI. Preparation and reactions of dimethyl 13,14,15,16-Tetranorlabd-8(17)-ene-12,19-dioate
Authors: Cambie RC , McNally HM , Robertson JD , Rutledge PS , Woodgate PD
Published: September 2010

The unsaturated diester (3) is conveniently prepared from the keto diester (2) by using a mixture of zinc, dibromomethane
and titanium tetrachloride. Its synthetic utility and that of derived products
has been explored.
The crystal structure of Bis[2-(pyridin-2-ylamino)-4-(pyridin-2-yl)thiazole]iron(II) Bis(tetrafluoroborate) trihydrate
Authors: Baker AT , Goodwin HA , Rae AD
Published: September 2010

The crystal structure of an
iron(II) complex of 2-(pyridin-2-ylamino)-4-(pyridin-2-yl)tliazoe
(paptH) has been determined by single-crystal X-ray
diffractometry. [Fe(paptH)2] [BF4]2.3H2O
is monoclinic, space group P21/c, with Z = 4 in a cell of dimensions
a 8.968(6), b 9.038(4), c 41.15(2)�, β
94.81(2)�. The disordered structure was refined to a residual R 0.0826 for 2549
observed reflections. The ligands and anions are orientationally
disordered, and the waters of crystallization are positionally disordered.
Comprehensive constrained refinement, with 220 parameters for 139 atom
positions, produced reliable geometry. The complex cation has a distorted
octahedral structure of meridional configuration with
both paptH ligands functioning as tridentates.
Substituent effects on the N.M.R. spectra of carboxylic acid derivatives. III. Correlation of 13C N.M.R. spectra of para substituted acetanilides and 4'-nitrophenyl 4-substituted benzoates with infrared carbonyl stretching frequencies, 1H N.M.R., rate and equilibrium data
Authors: O'Conner CJ , McLennan DJ , Calvert DJ , Lomax TD , Porter AJ , Rogers DA
Published: September 2010

The 13C n.m.r.
spectra of 17 monosubstituted benzenes, 14 para substituted acetanilides
and ten 4'-nitrophenyl 4-substituted benzoates have been measured in (CD3)2SO
and the chemical shifts have been compared with the infrared carbonyl
stretching frequencies of the substrates (in CCl4), the 1H
n.m.r. chemical shifts of protons close to the reactive site of protonation,
rates of hydrolysis or aminolysis and literature
values of the corresponding basicity constants and
rate constants. The observed substituent chemical shifts are non-additive and
this result has been discussed in terms of the electronic properties of -NHCOCH3
and -COOC6H4NO2. The 13C n.m.r. and
the i.r. data have been treated by single parameter
and dual substituent parameter linear free energy relationships and σR values
of best fit have been identified. Relative resonance and inductive
contributions have been discussed.
A unified ligand field model comprising the effects of electrostatics and covalence on molecular electronic energies
Authors: Steenkamp PJ
Published: September 2010

The relevance of models
describing molecular electronic energies including electrostatic as well as
covalence effects is outlined and a summary of developments resulting in the
present formulation is given. A simple, semi-empirical model based on a LCAO-MO
approximation and comprising the point charge electrostatic model and angular
overlap model is formulated. Although the present formulation is restricted to
the antibonding effects of covalence it is applicable to p, d, f and g orbital
energies. The mathematical and conceptual simplicity of the model derives from
the application of a re-parameterized ionic model and the superposition
principle for ligand contributions, the latter applied in the case of ionic as
well as antibonding effects. A physical interpretation of the model, for
diatomic as well as polyatomic molecules, is presented and the results of its
application to the pentachlorovanadate(IV) ion are cited.
The crystal and molecular structures of the ligand (E)-Pyridine-2-carbaldehyde Pyridin-2'-ylhydrazone and the palladium(II) complex Chloro[(E)-pyridine-2-carbaldehyde pyridin-2'-ylhydrazonato]palladium(II) which involves the coordination of the ligand in its anionic form
Authors: Casey AT , Hoskins BF , Traverso IP
Published: September 2010

The crystal and molecular structures of the ligand (E)-pyridine-2-carbaldehyde pyridin-2'-ylhydrazone
hydrate and its complex chloro[(E)-pyridine-2-carbaldehyde pyridin-2'-ylhydrazonato]palladium(II)
have been determined by single-crystal three-dimensional X-ray diffraction techniques. Crystals
of the ligand are monoclinic with space group P 21/c. The unit cell, which contains four molecules
of ligand together with approximately ten disordered water molecules, has the dimensions a 17.762(4),
b 3,8717(11), c 18.503(4) Ǻ and β 107.99(2)°. Crystals of the complex are triclinic with space
group P1, and the unit cell has the dimensions a 6.9721(3), b 9.0739(11), c 9.1304(9) Ǻ, α81.116(9),
β 88.778(8) and γ 81.392(8)°; Z = 2. The ligand structure was solved by direct methods and
refined with anisotropic thermal parameters for all non-hydrogen atoms and isotropic thermal
parameters for hydrogen and solvent atoms. The complex structure was solved by conventional
Fourier methods and refined with anisotropic thermal parameters for all non-hydrogen atoms.
A full-matrix least-squares method was employed for both structures based on 1295 and 2224
statistically significant reflections giving final values of R 0.061, Rw 0.068 and R 0.028, Rw 0.030
for the ligand and complex respectively.
The structure analysis of the ligand shows definite evidence of delocalization of lone pair
electrons in the hydrazine moiety. The ligand in its anionic form coordinates in a tridentate manner
to the palladium atom in the complex through the two pyridine nitrogen atoms and the distal
nitrogen of the hydrazine residue. A square-planar array is formed by a chlorine atom occupying
the fourth position. Molecular dimensions suggest that the lone pair on the proximal nitrogen
is delocalized over the entire molecule. Standard valence-bond and 'increased valence' methods
have been applied in order to determine resonance schemes consistent with the observed structures
of both the ligand and its complex.
Crystal and molecular structure of a natural vanadyl porphyrin
Authors: Miller SA , Hambley TW , Taylor JC
Published: September 2010

The crystal and molecular
structure of a vanadyl deoxophylloerythroetioporphyrin
(dpep) extracted from oil shale has been determined
by single crystal X-ray diffraction. The compound crystallizes in space group
P21/c of the monoclinic system with four formula units in a cell of
dimensions a 12.912(3), b 14.151(4), c 18.404(8) �, β 70.34(2)�. Block matrix least-squares
refinement gives a final R index of 0.077 for 2296 reflections. The planar
molecules are packed almost parallel, with the chloroform solvent molecules
lying between the planes and weakly associated with the vanadyl
oxygen. The molecular structure establishes the presence of an isocyclic five-membered ring, which suggests that the
molecule is a derivative of chlorophyll.
Crystal structure of N,N '-Ethylenebis(1,1,1-Trifluoro-4-iminopentan-2-one)
Authors: Cea-Olivares R , Rodriguez I , Rosales MJ , Toscano A
Published: September 2010

The crystal structure of N,N'-ethylenebis(1,1,1-trifluoro-4-iminopentan-2-one) (tfaen) was determined: C12H14F6N2O2,
M 342.04, monoclinic, space group P21/n, a 6.939(2), b 20.529(5), c 10.662(2) �, V 1507.84 �3 β
96.87(2)�, p(calc.) 1.506 g cm-3 (Z = 4), F(000)680, �(Cu Kα)
13.15 cm-1. The structure was solved by direct methods and refined
to a final R value of 0.073 for 1198 unique reflections. Discrete molecules in
the crystal are characterized by a conjugated enamino
ketone structure with intramolecular hydrogen bridges.
Heterocyclic amplifiers of phleomycin. III. 5-Substituted 1 H-Imidazo[4,5-b]pyrazines and 6-substituted Pyrazino[2,3-b]pyrazines
Authors: Barlin GB , Ireland SJ
Published: September 2010

A series of 1H-imidazo[4,5-b]pyrazines
has been prepared from 5-bromopyrazine-2,3-diamine and
5-bromo-3-methylaminopyrazin-2-amine with diethoxymethyl
acetate, acetic anhydride or potassium ethyl xanthate;
and 6-substituted pyrazino[2,3-b]pyrazines from 5-bromopyrazine-2,3-diamine
with α, β-dicarbonyl compounds. Reactions
of these compounds have been examined. Diazomethane methylation of 5-bromo-1H-imidazo[4,5-b]pyrazine-2(3H)-thione gave five dimethyl derivatives which have been
identified as the 1,3- and the four N,S-dimethyl derivatives. 2-Bromo-6,7-dimethylpyrazino[2,3-b]pyrazine
with 0.4 M and 2.0 M methanolic sodium methane-thiolate gave as principal products
2,3-dimethyl-6-methylthio- and 2,3-dimethyl-6,7-bismethylthio- pyrazino-[2,3-b]pyrazines, respectively. The 1H-imidazo[4,5-b]pyrazines showed only slight activity as amplifiers
of phleomycin.
A synthesis of Benzo[c][1,8]naphthyridinones: an exception to the Knorr reaction
Authors: Deady LW
Published: September 2010

The reaction of 1-methoxyisoquinolin-3-amine
with ethyl acetoacetate, and subsequent ring closure,
is reported. Conrad-Limpach synthesis leads to the
expected 4(1H)-one.
The same isomer is formed under Knorr conditions (hot
polyphosphoric acid), while a less acidic medium (hot
acetic acid) gives the 2(1H)-one.
Synthesis and resolution of an asymmetric arsonium cation. Crystal and molecular structures of (R)-Benzyl(methyl)(4-methylphenyl)(naphthalen-1-yl)- arsonium bromide and hexafluorophosphate
Authors: Allen DG , Raston CL , Skelton BW , White AH , Wild SB
Published: September 2010

The (�)-benzyl(methyl)(4-methylphenyl)(naphthalen-1-yl)arsonium
cation has been synthesized and subsequently resolved by fractional
crystallization of monohydrogen [R-(R*,R*)]-2,3-bis(benzoyloxy)- butanedioate
salts. The separated diastereoisomers were converted into the corresponding
optically active arsonium bromides by ion-exchange column chromatography. The
absolute configuration of the arsonium cation exhibiting a positive rotation at
589 nm (sodium D line) has been established as (R) by single-crystal X-ray
analysis of both the bromide and hexafluorophosphate salts. The arsonium
bromide with [α]D + 54.8�(c, 0.62 in CH2Cl2)
crystallizes in the orthorhombic space group P212121
(D24, No.19) with a
22.472(8), b 15.724(7), c 12.585(5) � and U 4447(3) �3. The corresponding hexafluorophosphate with
[α]D + 19.3� (c, 0.5 in CH2Cl2)
crystallizes in the same space group with a
23.56(2), b 16.40(1), c 13.12(1) � and U 5067(6) � 3. Benzylidene transfer to benzaldehyde from
the arsonium ylide derived from either of the arsonium salts produced optically
pure (–)-(S)-methyl(4-methylphenyl)(naphthalen-1-yl)arsine, [α]D
- 115.9� (c, 0.593 in CHCl3), and partly resolved
[R-(R*,R*)]-2,3-diphenyloxiran.
Photosolvolysis of bridgehead quaternary ammonium salts. I. Synthesis of some 3-benzazonine derivatives
Authors: Bremner JB , Winzenberg KN
Published: September 2010

The medium-ring
heterocyclic derivative 7,9,10-trimethoxy-3-methyl-2,3,4,5,6,7-hexahydro-1H-3- benzazonine
(10a) was obtained from the ultraviolet irradiation of the reduced
pyrrolo[2,1-aliso-quinolinium iodide salt (9a) in methanol, along with N-[2-(3,4-dimethoxypheny1)ethyl]-4,4-dimethoxy-
N-methylbutan-1-amine (11a) and N-[2-(3,4-dimethoxyphenyl)ethyl]-2-methoxy-N-methylpyrrol-idinium iodide (13a).
Analogous products were also obtained from the photolysis of 8,9-dimethoxy-
4-methyl-1,2,3,5,6,10b-(10b-D)hexahydropyrrolo[2,1-a]isoquinolinium
iodide (9b) and 8,9-di-methoxy-4,10b-dimethyl-1,2,3,5,6,10b-hexahydropyrroo[2,-a]isoquinolinium
iodide (9c), with the exception of no pyrrolidinium
salt from the latter. Photolysis of (9a) and (9c) in water afforded the
corresponding hexahydro-1H-3-benzazonin-7-ols (10d) and (10e), and the amino
aldehyde (12a) and the amino ketone (12b) respectively.
Experiments directed towards the synthesis of anthracyclinones. VIII. Functionalization of hydroxyanthraquinones by reductive Claisen rearrangements
Authors: Boddy IK , Boniface PJ , Cambie RC , Craw PA , Huang Z , Larsen DS , McDonald H , Rutledge PS , Woodgate PD
Published: September 2010

Gentle heating of
allyloxyanthraquinones with sodium dithionite in dimethylformamide/water effects
a rapid and controlled rearrangement to give high yields of
2-allylhydroxyanthraquinones.Starting from quinizarin,
key intermediates for two synthetic routes to 4-demethoxydaunomycinone have
been prepared from products by means of two such reductive Claisen
rearrangements.
Oxidative cyclizations. VII. Cyclization of 2-substituted anilines with alkaline hypohalite
Authors: Dyall LK
Published: September 2010

The Green-Rowe oxidation of
2-nitroanilines with alkaline hypochlorite, to yield benzofuroxans,
is demonstrated by studies of the visible spectra of transient intermediates to
proceed through N-chlorination and a singlet nitrene.
Two variations on the route to the nitrene are
possible. The cyclization step is represented as an internal capture of the nitrene by the ortho substituent, and on this basis the
Green-Rowe oxidative cyclization is now extended to anilines whose ortho
substituent is benzoyl or phenylazo. It is not
however successful for ortho phenyl. Azo compounds were observed as byproducts
in some of these reactions, and are shown to arise via N,N-dichloroanilines.
The reactions of superoxide ion with arylhydrazines
Authors: Crank G , Gately GE , Makin MIH
Published: September 2010

Arylhydrazines react with
potassium superoxide to give a variety of products, most of which are derived
from interaction of aryl radicals with the solvent. Phenylhydrazine in toluene gives three
isomeric methylbiphenyls, diphenylmethane and bibenzyl. In pyridine, the
products identified were 2-, 3- and 4-phenylpyridine. A more complex range of
products was obtained from substituted phenylhydrazines. Products are
consistent with a process in which superoxide ion abstracts hydrogen atoms from
the hydrazines giving radical intermediates, including aryl radicals, which
react with the solvents.
Dihexadecyl Phosphate Vesicles: Difference in the Spectroscopic Properties of Tris(2,2′-bipyridine)ruthenium(II) Adsorbed on the Inner and Outer Surfaces
Authors: Tricot Y , Furlong DN , Mau AWH , Sasse WHF
Published: September 2010

The visible absorption spectrum of tris (2,2′-bipyridine)ruthenium(II) [ Ru ( bpy )32+] adsorbed on the outer surface of dihexadecyl phosphate vesicles is indistinguishable from the spectrum of free Ru ( bpy )32+ in aqueous solution. By contrast, the absorption spectrum of Ru ( bpy )32+ that is entrapped in vesicles by adsorption on inner surfaces exhibits a red shift in its visible absorption peak, and the extinction coefficient for this peak is increased. The emission spectrum for outer-adsorbed Ru ( bpy )32+ is red-shifted whilst that for inner-adsorbed Ru ( bpy )32+ is blue-shifted, compared with the spectrum for free Ru ( bpy )32+ in solution. The excited state of Ru ( bpy )32+ was longer lived, and was much less sensitive to quenching by oxygen, when the complex was adsorbed on inner vesicle walls. The above spectral variations indicate that the adsorption of Ru ( bpy )32+ on inner surfaces occurs in a way which leads to more spatial restriction on Ru ( bpy )32+ ions than does adsorption on outer surfaces of the bilayer . This asymmetry may be due to differences in the packing of dihexadecyl phosphate molecules as well as in the ionic strength of inner and outer aqueous environments.
The Chemistry of Aryllead(IV) Tricarboxylates. The C-Arylation of Nitroalkanes and Nitronate Salts with Aryllead Triacetates
Authors: Kozyrod RP , Pinhey JT
Published: September 2010

2-Nitropropane reacts with phenyllead triacetate in dimethyl sulfoxide to give 2-nitro-2-phenylpropane in good yield. This arylation of nitroalkanes has been examined with a variety of substrates and a number of aryllead triacetates, and in those cases where there was no steric hindrance the reaction was found to be quit general. Reactions of nitroethane and methyl nitroacetate, compounds with two α- hydrogens, were readily controlled to give either the mono- or di-arylated products. The corresponding nitronate salts were also examined and found to undergo the arylation reaction in similar yield but at a very much faster rate.
Synthesis of Some Polybrominated Diphenyl Ethers Found in Marine Sponges
Authors: Francesconi KA , Ghisalberti EL
Published: September 2010

A simple general route for the synthesis of polybrominated diphenyl ethers is reported.
The Stereochemistry of Organometallic Compounds .XXVII. Nucleophilic and Electrophilic Substitution-Reactions of Conformationally Restricted Arenechromium Compounds
Authors: Jackson WR , Rae ID , Wong MG
Published: September 2010

The regioselectivity of reaction of tricarbonyl (1,1- dimethylindane )chromium with selected electrophiles and nucleophiles has been shown to be influenced by the preferred conformation of the tricarbonylchromium group. Nucleophiles preferentially react at carbon atoms eclipsed by a chromium-carbonyl bond and electrophiles at carbon atoms in staggered positions. When similar reactions were attempted with some chelated arenechromium dicarbonyl phosphorus compounds only low yields of substitution products were obtained.
Asymmetric Hydrocyanation of Aldehydes in Crystalline Beta-Cyclodextrin Complexes
Authors: Gountzos H , Jackson WR , Harrington KJ
Published: September 2010

Exposure of crystalline β- cyclodextrin complexes of aldehydes to hydrogen cyanide gives cyanohydrins in moderate to good yields. The hydrocyanation reaction displayed enantioselection, and the cyanohydrins were formed with optical yields in the range from 0 to 33%.
The Photochemistry of the Ruthenium(II) Complex [Ru(No)Br3(Et2S)2]
Authors: Coll RK , Fergusson JE , Keong TS
Published: September 2010

The photochemistry of the complex [ Ru (NO)Br3(Et2S)2] in chloroform initially involves the loss of some NO, which in the presence of dioxygen catalyses the oxidation of the coordinated diethyl sulfide to sulfoxide and sulfone.
Methylmercury Generation in Seawater by Transmethylation Reactions of Organolead and Organotin Compounds With Inorganic Mercury as Monitored by Multinuclear Magnetic-Resonance and Electrochemical Techniques
Authors: Howell GN , Oconnor MJ , Bond AM , Hudson HA , Hanna PJ , Strother S
Published: September 2010

The generation of methylmercury species by reactions between inorganic mercury and methylated forms of lead and tin in seawater and other matrices is described. The reactions were investigated by 119Sn, 199Hg and 207Pb multinuclear Fourier transform magnetic resonance spectroscopy and by differential pulse polarography and anodic stripping voltammetry. Methylmercury chloride is shown to be produced from mixtures of inorganic mercury with methyltin or methyllead species over the 10-2-10-8 M concentration range at ambient temperatures in seawater and artificial seawater.
C-13 NMR Investigation of the Ph-Dependence of Copper(II) Complexation to Glucuronic-Acid
Authors: Cook IB , Magee RJ , Payne R , Ternai B
Published: September 2010

The interaction of paramagnetic copper(II) ions with glucuronic acid in aqueous solution was studied by differential line broadening analysis of carbon-13 n.m.r. spectra. Evidence is presented for pH-dependent complexation behaviour, with simple carboxylate complexation dominating below pH 4.5, and a more complicated bidentate coordination mode involving O 3 above pH 4.5.
Elatenyne—a Pyrano[3,2-B]Pyranyl Vinyl Acetylene From the Red Alga Laurencia elata
Authors: Hall JG , Reiss JA
Published: September 2010

Elatenyne (3,7-dibromo-6-ethyl-2-(pent-2′-en-4′-ynyl ) octahydropyrano [3,2-b] pyran ) was isolated as an oil from the marine red alga Laurencia elata. Its structure and those of three derivatives were assigned on the basis of spectroscopic, predominantly n.m.r ., data.
Studies in Bile-Salt Solutions. XXII. The Effect of Reversed Micelles and of Aerosol-OT Aqueous Micelles on the Esterase Activity of Bile-Salt-Stimulated Human-Milk Lipase. Determination of Enzyme-Inhibitor Complex Dissociation Constants
Authors: Oconnor CJ , Stockley IC , Walde P
Published: September 2010

The esterase activity of bile-salt-stimulated human milk lipase has been measured against several 4-nitrophenyl alkanoate esters, including 4-nitrophenyl propionate, in reversed micellar solutions of several surfactants. The reaction media used were Aerosol-OT in isooctane, hexadecyltrimethylammonium bromide in chloroform/n-octane (1 : 1 v/v) or in chloroform, Triton X-100 in carbon tetrachloride or isooctane, lecithin in n-octane or diethyl ether/methanol (95 : 5 v/v) or benzene, and Brij 56 in cyclohexane . The reaction conditions varied over a range of cosolubilized water concentrations and initial pH values of added borate, glycine and Tris buffer solutions. In all cases decreased enzymic activity was observed, even if sodium taurocholate was present in the reaction medium. A detailed examination has been made on the effect of changing concentrations of 4-nitrophenyl propionate and of Aerosol-OT on the esterase activity of bile-salt-stimulated human milk lipase at 298 K in aqueous solutions of Tris buffer at pH 7.5. The inhibition induced by Aerosol-OT was identified as being reversible and mixed. The dissociation constants of the enzyme-surfactant complex and of the (enzyme-ester)-surfactant complex have been calculated to be equal to 0.125 and 0.48 mmol 1-1, respectively.
Thermal Degradation of Polymers.II. Synthesis and Characterization of a Compound Which Models the Head-to-Head Linkage in Poly(Methyl Methacrylate)
Authors: Fallon GD , Felsbourg ML , Holland KA , Rae ID
Published: September 2010

As models for a poly(methyl methacrylate ) chain which contains a head-to-head unit, the (�)- and meso -isomers of tetramethyl 2,4,5,7-tetramethyloctane-2,4,5,7-tetracarboxylate have been synthesized by oxidative dimerization of a trimethylsilyl ketene acetal. The isomers were characterized by 1H and 13C n.m.r. spectroscopy, and the molecular structure of the meso -isomer was determined by X-ray crystallography. Molecular mechanics (MM2) calculations showed that three conformations of each isomer, about its central bond, had comparable steric energies. Calculated energy barriers to interconversion of the conformers were low.
On the Flat-Band Potential of n-Type Cadmium Telluride in Alkaline Selenide, Polyselenide Electrolytes
Authors: Lyons LE , Young TL
Published: September 2010

The flat-band potential Efb of n-CdTe in alkaline K2Se solution was determined by the Mott-Schottky technique as a function of properties of the crystal and electrolyte. The experimental value, c.- 2.0 V v. s.c.e., is more negative than the value calculated by assuming the absence of localized surface charge, -0.35 V v. s.c.e. For a given electrolyte, Epb depended on the crystal orientation, and became more negative in the order (111), (110), (111). These results are consistent with specific adsorption of anionic selenide species on surface cadmium atoms. For a freshly prepared CdTe electrode, Efb depended on the selenide ion concentration in a Nernstian manner, consistent with sub-monolayer adsorption of HSe-. In contrast, when electrodes had been exposed to selenide electrolytes for several days, Efb was less dependent on the selenide ion concentration, in some cases being constant over four orders of magnitude of [Se2-]. Such results were consistent either with saturation of the surface with adsorbed ions, or with pinning. As the electrolyte was oxidized, Ub increased linearly with Eredox, reached a maximum value at -0.81 V v. s.c.e., and then decreased, so that neither the ideal model nor the Fermi level pinning model applied. Models which assumed adsorption only of HSe- were inconsistent with the observed behaviour, but the results were explained quantitatively by a model which assumed the competitive adsorption of HSe- and Se on the semiconductor surface. Such a model was consistent also with the independence of Efb and the total selenide concentration observed in some experiments. .The largest built-in potential observed was 1.23 V. An improved method of preparing CdTe electrodes is described.
An X-Ray Crystallographic Study of Tris(O-Methyl Dithiocarbonato)-Arsenic(III), Tris(O-Methyl Dithiocarbonato)-Antimony(III) and Tris(O-Methyl Dithiocarbonato)-Bismuth(III)
Authors: Snow MR , Tiekink ERT
Published: September 2010

The crystal structures of the methylxanthates of AsIII (two polymorphs), sbIII and BiIII are reported. In the monoclinic form of As(S2COCH3)3 the molecular threefold symmetry, as found in the previously reported trigonal As(S2COCH3)3, is not crystallographically imposed. The distorted octahedral environments about each of the ASIII centres is defined by three asymmetrically chelating xanthate ligands. In contrast, the sbIIIand BiIII analogues adopt different stereochemistries based on pseudo-m symmetry. In addition, the Sb (S2COCH3)3 and Bi(S2COCH3)3 molecules associate to form loosely held dimers , through weak intermolecular Me…S interactions, in their respective crystal lattices. Crystals of β-As(S2COCH3)3 are monoclinic, P21/c, with unit cell parameters a 14.816(4), b 9.641(6), c 21.255(6) �, β 90.18(2)�, Z = 8. The antimony and bismuth compounds are isomorphous, crystallizing in the triclinic space group P1, with cell dimensions (bismuth details given second) a 5.904(1), 5.924(3); b 10.4891(8), 10.499(3); c 12.3635(9), 12.485(4) �; α 95.993(6), 95.99(3); β 100.92(1), 101.76(4); γ 99.04(1), 101.45(4)�; Z = 2, 2. The structures were solved by normal Fourier methods and refined by a full-matrix least-squares procedure in each case on reflections which satisfied the I ≥2.5σ(I) criterion. Final refinement details for the β arsenic (antimony, bismuth) compounds: R 0.034 (0.027, 0.055), Rw 0.034 (0.029, 0.052) for 2777 (2115, 1894) reflections.
The Synthesis of 1,10-Phenanthroline Esters Containing Unsaturated C18 Side Chains
Authors: Holan G , Wernert GT
Published: September 2010

Octadeca-6,9,12-trienyl 3,4,7,8-tetramethyl-1,10-phenanthroline-2-carboxylate and 3,7,8-tri-methyl- 1,10-phenanthrolin-4-ylmethyl octadeca-9,12,15-trienoate have been synthesized. Furthermore, two series of 1,10-phenanthroline esters substituted in the 2-position with C18 unsaturated side chains have also been synthesized.
Investigation of Readily Available Chiral Compounds for Preparative Scale Resolutions
Authors: Duke CC , Wells RJ
Published: September 2010

Diastereoisomeric esters were formed by reaction of racemic carboxylic acids with the readily available hydroxy lactone derivatives, 2,3-O-isopropylidene-D(+)-ribono-l,4-lactone, D(-)-2- hydroxy-3,3-dimethylbutyro-1,4-lactone (D(-)-pantolactone) and 1,2-O-isopropylidene-(+)-α-D-glucofuranurono-6,3-lactone. In all cases separation of the diastereoisomeric esters was achieved by crystallization and/or chromatography. Purity of the diastereoisomers could be determined by h.p.l.c. or by 1H n.m.r. Hydrolysis under mild basic conditions followed by treatment with acid gave optically pure carboxylic acids. The facile separation by crystallization and/or chromatography of diastereoisomers prepared from racemic endo-1,4,5,6,7,7-hexachlorobicyclo[2.2.l]hept-5-ene-2-carboxylic acid suggested that the resolved acid may be useful as a resolving agent. This was shown by separation of diastereoisomers formed from the resolved acid and racemic 1-(3′-phenoxyphenyl)prop-2- yn-1-ol and racemic 1-cyano-1-(3'-phenoxypheny1)methanol respectively. Optically pure 1-(3'-phenoxypheny1)prop-2-yn-1-ol was obtained by hydrolysis of the separated diastereoisomers.
The Crystal and Molecular Structure of Ph2PCH2P(Se)Ph2
Authors: Colton R , Hoskins BF , Panagiotidou P
Published: September 2010

Crystals of Ph2PCH2P(Se)Ph2 are monoclinic, P21/c, a 8 104(1), b 17.756(3), c 15.350(3) �, p 97.74(2)°. Thecompound is molecular with a P-Se bond distance of 2.103(1) �.
Argon Matrix Infrared Spectroscopic Evidence for the Generation of Pentatetraenone by Flash Pyrolysis of Suitable Precursors
Authors: Brown RFC , Coulston KJ , Eastwood FW , Irvine MJ , Pullin ADE
Published: September 2010

Five compounds were investigated as precursors for the pyrolytic generation of pentatetraenone, H2C=C=C=C=C=O. These were (1)-(4): 3- ethenylidenebicyclo [2.2.1]hept-5-ene with the following 2,2 substituents : H, COOCOCF3 (1); H, 13COOCOCF3 (1′); (COOCOCF3)2 (2); (COO)2C(CH3)(OCH3) (3); (COO)2Si(CH3)2 (4) and 5-(3′- methylenebicyclo [2.2.1]hept-5′-en-2′-ylidene)-2,2-dimethyl-1,3-dioxan-4,6-dione (5). The five precursors were pyrolysed in a stream of argon at temperatures in the range 350-725°C and the pyrolysate -argon mixture condensed on a CsI plate at c. 10 K. Infrared spectra were obtained between 4000 and 250 cm-1. All five precursors gave two strong bands in the spectral region 2070-2250 cm-1, possibly attributable to pentatetraenone. At lower pyrolytic temperatures the more intense of the two bands was a broad band centred at c. 2128 cm-1 [precursors (1)- (4)] or at c. 2094 cm-1 [precursor (5)]. At higher pyrolytic temperatures these bands were diminished in intensity and replaced by a narrow band at 2207 cm-1 for all five precursors. Bands due to the expected other products for each pyrolysis reaction to form pentatetraenone were observed. H2C413CO ( pentatetraenone substituted by 13C at the carbonyl carbon atom) was prepared by pyrolysis of precursor (1′). We assign the broad bands at c. 2128 cm-1 [precursors (1)-(4)] and at c. 2094 [precursor (5)] to incompletely pyrolysed precursor in which cyclopentadiene has been retained but decomposition in the rest of the molecule has resulted in formation of a =C=C=O group. Bands at 2207, 2068 and 1726 cm-1 we assign to v2-v4 of pentatetraenone. Corresponding bands at 2168, 2056 and 1720 cm-1 are observed in the spectrum of H2C413CO.
Lewis-Base Adducts of Main Group 1 Metal Compounds. VI. Novel Hydrogen Bonding and a Novel Binuclear Aquated Lithium Cation in [(H2O)2Li(OH2)2Li(OH2)2]2+.2Cl-.6L (L = 2,6-Dimethylpyridine)
Authors: Raston CL , Whitaker CR , White AH
Published: September 2010

The title compound, isolated as an artefact of the recrystallization of lithium chloride from 2,6-dimethylpyridine, and the subject of a single-crystal X-ray study (R = 0.063 for 1200 'observed' reflections), contains the novel centrosymmetric [(H2O)2Li(OH2)2Li(OH2)2]2+ cation. Li- O(bridging) are 2.05(2), 2.00(2)Ǻ; Li-O (terminal) are 1.88(2), 1.88(2)Ǻ. Li-O-Li is 89.1(7) and O-Li-O′ (core) is 90.9(8)°. The angle between the terminal water oxygens at the lithium is 122.6(11)° and O(terminal)-Li-O(bridge) range from 101.7(7) to
123.0(10)°. An elegant hydrogen bonding scheme is found, one hydrogen atom from each of the water molecules being associated with the chloride counterion at 2.0- 2.2 Ǻ; the other hydrogen atom of each water is directed towards the nitrogen atom of one of each of the base molecules, H…N ~ 1.6-2.1 Ǻ.
A Mechanistic Study of the Wittig Reaction Between a Cyclic Anhydride and a Stabilized Phosphorane
Authors: Abell AD , Clark BM , Robinson WT
Published: September 2010

The structure of an isolated acyclic intermediate in the Wittig reaction between succinic anhydride and ethoxycarbonylmethylenetriphenylphosphorane has been shown by X-ray structure analysis and DEPT n.m.r .to be the phosphorane (4a) rather than the alternative phosphonium salt (4b). However, an intermediate was not observed in the Wittig reaction between the phosphorane (1b) and cyclic anhydrides. Both the stabilized phosphoranes (1a,b) react with succinic, phthalic and glutaric anhydrides stereoselectively to produce E enol lactones. Some mechanistic aspects are discussed. The assignment of the enol lactone stereochemistry was achieved by n.O.e. difference n.m.r. methods.
The Kinetics of Water Exchange on Aqueous Aquapentacyanocobaltate(III)
Authors: Bradley SM , Doine H , Krouse HR , Sisley MJ , Swaddle TW
Published: September 2010

The temperature and pressure dependences of the rate of exchange of oxygen-18 between labelled Co(CN)5OH22- and solvent water at pH 3 and ionic strength 0.35 mol l-1 are governed by the following first-order kinetic parameters: kex = 5.8x10-4 s-1 at 298 K; ΔH‡ = 90.2 kJ mol-1; ΔS‡ = -4 J K-1 mol-1; and ΔV‡ = + 7 cm3 mol-1 (mean value, 0-400 MPa ). Although these results are indicative of a strongly dissociative mode of
activation, the rate of water exchange is about twice that predicted by previous workers on the basis of a limiting dissociative (D or SN1 lim ) mechanism for the replacement of water in Co(CN)5OH22- by other ligands . This implies that the purported intermediate Co(CN)52- cannot be long-lived on the time scale of relaxation of the second coordination sphere, and supports the contention of Burnett and coworkers that the mechanism of this textbook example of a series of dissociatively activated ligand substitution reactions is properly classified as dissociative interchange (Id).