bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclophanes. XII* The Synthesis of [2,2](3,3')Biphenylo(3,6)-phenanthrenophanes and Attempted Conversions into Hepta[8]circulene
Authors: Leach DN , Reiss JA
Published: September 2010

[2,2](3,3')Biphenylo(3,6)phenanthrenophane-1,15-diene (6) has been
synthesized by a ring-contraction procedure from the dithiacyclophane
(10). The corresponding saturated compound (5) was prepared by pyrolysis of the
sulfone (12). The stereochemistry of both (5) and (6) in solution has been determined
to be syn
from spectral evidence and neither compound shows any evidence of
conformational ring-flipping or extensive mobility. Several attempts to convert
the diene (6) into hepta[8]circulene
are recorded. The factors affecting the photochemical ring-closures of cyclophanedienes are discussed.
The Synthesis of Melatonin Antigens
Authors: Blair IA , Seaborn CJ
Published: September 2010

The synthetic strategy required
for the development of a radioimmunoassay for the hormone melatonin* is
discussed. A facile entry into the N-(1-carboxyalkyl)melatonins
(9), (10), (11) is described. The utility of these compounds as versatile
haptens for the synthesis of melatonin antigens (12), (13), (14) is
demonstrated.
Stereoselective Reduction of 3-O-Hexofuranosyl S-Methyl Dithiocarbonates with Tributyltin Deuteride
Authors: Patroni JJ , Stick RV
Published: September 2010

The reduction of several 3-O-hexofuranosyl (gluco, allo, galacto, gulo) S-methyl dithiocarbonates with
tributyltin deuteride leads to highly stereoselective syntheses of
3-deoxy-[3-2H]hexofuranoses.Correspondingly, the
reduction of the 3-O-[3-2H]hexofuranosyl
(allo, gulo) S-methyl
dithiocarbonates with tributyltin hydride leads to the epimeric (C3) 3-deoxy-[3-2H]hexofuranoses,
and the reduction with tributyltin deuteride leads to the 3-deoxy-[3,3-2H2]hexofuranose.
The Effects of Solvent and Oxygen Pressure on the Autoxidation of Benzoin Catalysed by Nickel Acetate
Authors: Chaplin RP , Vorlow S , Wainwright MS
Published: September 2010

Kinetic results are
reported for the autoxidation of benzoin, catalysed by nickel acetate in
methanol and ethanol. The reaction in methanol is first order with respect to
benzoin and the catalyst and is independent of the oxygen partial pressure. The
reaction is non-free-radical and probably involves a coordination complex
between the substrate and the catalyst. In ethanol the reaction is found to
obey second-order reversible kinetics with respect to benzoin and first-order
kinetics with respect to the catalyst. The oxidation is also at least 10 times
faster in ethanol than in methanol at 303 K.
Purine Analogues as Amplifiers of Phleomycin. IV. Some Pyrazolo[3,4-d]pyrimidine, Imidazo[4,5-b]-pyridine, Imidazo[4,5-c]pyridine and Quinazoline Derivatives
Authors: Brown DJ , Danckwerts L , Grigg GW , Iwai Y
Published: September 2010

1-Methyl-1H-pyrazolo[3,4-d]pyrimidine-4(5H)-thione (1b), its 1-phenyl analogue (1c),
1H-pyrazolo- [3,4-dlpyrimidine-4,6(5H,7H)-dithione (2a), its 1-methyl (2b) and 1-phenyl (2c)
derivatives, 1H-imidazo[4,5-b and 4,5-clpyridine-2(3H)-thiones (5)
and (6), and quinazoline-4(3H)-thione (9) react with simple alkyl halides,
2-chloroacetamide, 2-chloro-N-methylacetamide
or 2-bromopropionamide to give the corresponding thioethers
(3e-n), (4a-1), (7a-c), (8a-d) and (10). The unmethylated
amides among these show dual NH peaks in their n.m.r. spectra. Activities as
amplifiers of phleomycin against E. coli
are tabulated and discussed.
Tautomerism in N-Heterocycles. IV. Pyrazino[2,3-d]pyridazine-5,8-diol
Authors: Barlin GB
Published: September 2010

Pyrazino[2,3-d]pyridazine-5,8-diol as the neutral molecule in
aqueous solution has been shown to exist predominantly as 8-hydroxypyrazino[2,3-d]pyridazin-5(6H)-one by comparison of its u.v.spectra and pKa
values with those of N- and O-methyl derivatives.
Cobalt(III) Complexes with 4-Methyldiethylene-triamine[2,2'-Methyliminodi(ethylamine)]: Their Separation, Characterization and Reactions
Authors: Searle GH , Lincoln SF , Teague SG , Rowe DG
Published: September 2010

An efficient synthesis of
2,2'-methyliminodi(ethylamine) trihydrochloride
(medien,3HCl) from diethylenetriamine (dien) is described. The reactions [CO(NH3)5Cl]
C12+2medien, and oxygen-oxidation of cobalt(II)+2medien, with
charcoal give only the s-fac isomer of [Co(medien)]3+.
A little s-fac-[Co(dien)(medien)]3+ is
also always formed, and this arises by demethylation
of s-fac-[Co(medien)2]3+ with oxygen on charcoal.
The substitution reaction [Co(NH3)5Cl] Cl2 + 1.6
medien + 0.4 dien produces
a complicated mixture of s-fac-[Co(medien)2]3+,
all three isomers s-fac,
u-fac and mer of [Co(dien)(medien)]3+, and all three isomers of [Co(dien)2]3+. A procedure using
exchanges of the counter-ions, crystallization, and chromatography on SP-Sephadex cation-exchange resin is described for separating
and isolating the products, and pure s-fac-[Co(dien)(medien)] (ClO4)3 is obtained preparatively by this means. From isomerization of this
complex in water the pure u-fac and mer [Co(dien)(medien)]3+
isomers are isolated. 13C and 1H N.M.R. and visible
spectra of the compounds are reported. The equilibrium isomer proportions of
[Co(dien)2]3+, [Co(dien)(medien)]3+ and
[Co(medien)2]3+ are discussed.
Some particular charcoal samples, which lack catalytic activity towards
cobalt(III) equilibrations, effect the unusual conversion of s-fac-[Co(medien)2]3+ into u-fac-[Co(arnam)]3+
(amam = 2,3-bis[(2-aminoethyl)(methyl)amino-ethylimino]-1-methylpiperazine).
Crystal Structures of the cis- and trans-Chlordanes and Their Photoisomers
Authors: Knox JR , Raston CL , White AH
Published: September 2010

The crystal structures of
the cis- and trans-chlordanes and their photoisomers, C10H6Cl8,
have been determined at 295(1) K by direct methods and refined by least
squares. (1) cis-Chlordane: monoclinic P21/c, a 13.742(9), b 8.073(4), c 13.299(5) �, β 93.81(4)�, Z 4. R 0.050 (1322 'observed' reflections). (2) trans-Chlordane: monoclinic, P21/a, a 15.762(5), b 7.694(2), c 12.526(4) �,
β 93.38(4)�, Z 4. R 0.052 (1678 'observed' reflections). (3) Photo-cis-chlordane: monoclinic, P 21/n,
a 12.403(3), b 13.830(4), c 8.310(2) �,
β 96.75(2)�, Z 4. R 0.056 (1501 'observed' reflections). (4) Photo-trans-chlordane: monoclinic, P21/c,a 16.521(5), b 6.699(2), c
14.431(6)& 11 115.68(3)�, Z 4. R 0.047 (1302 'observed' reflections). An
exceedingly long carbon-carbon bond (1.66(1) �) is observed in (4).
Synthetic Plant Growth Regulators. The Synthesis of C-o-Carboxyphenyl Derivatives of Pyrimidine
Authors: Harris RLN , Huppatz JL , Teitei T
Published: September 2010

Synthetic routes to o-carboxyphenyl derivatives of
pyrimidine, required for testing as potential plant growth regulators, are
described. 2-(4-Phenylpyrimidin-2-yl)benzoic acid (3), 2-(2-phenylpyrimidin-
4-yl)benzoic acid (4) and 2-(2-phenylpyrimidin-5-yl)benzoic acid (5) were
prepared by utilizing amide-acid chloride intermediates in the generation of
the pyrimidine ring in each instance.
Crystallographic and N.M.R.-Relaxation Studies on Bis [{N,N'-(1,3-dimethylpropanediylidene)dianilinato}(1 - )]nickel(II)
Authors: Healy PC , Bendall MR , Doddrell DM , Skelton BW , White AH
Published: September 2010

A single-crystal X-ray
structure determination of bis[{N,N'-(1,3-dimethylpropanediyldene)dianilinato)(1-)]nickel(II) at 295 K shows that, within
each of the two independent molecules of the complex within the structure, the
nickel atom is chelated by two of the bidentate
ligands and is thus four-coordinate. Because of the intramolecular interactions
between the phenyl substituents of the ligands, the metal atom environments are
highly irregular, although consistent between the two molecules. There are no significant
deviations in the Ni-N distances from the mean of 1.965�; but the interligand N-Ni-N angles about the nickel range from 110.4
to 134.7�. A theoretical calculation of the 13C and 1H
nuclear relaxation times using the X-ray-determined metal-nuclear separations
reproduces the experimentally observed relaxation times for selected positions
within the complex, provided ligand-centred effects are taken into account.
Mathematical complexity prevents a complete theoretical calculation of the
relaxation times for ligand atoms with varying distances from the nickel atom.
Assignment of the 13C N.M.R. Spectra of Some 22,26-Epiminocholestanes 22,26-Epiminocholest-22(N)-enes and Some 3β-Amino Steroidal Alkaloids
Authors: Bird GJ , Collins DJ , Eastwood FW , Exner RH
Published: September 2010

The synthesis of a number
of 22,26-epiminocholestanes and 22,26-epiminocholest-22(N)-enes, and the assignment of their 13C
N.M.R. spectra are described. The 13C N.M.R. spectra of the new 3β-amino
steroidal alkaloids solacallinidine (12a) and soladunalinidine (lld), and some
derivatives, are also assigned and the previously described spectra of the
known 3β-amino alkaloids solanocapsine (13) and jurubidine (15) are
reassigned. The assignments are based on deuterium labelling, paramagnetic
broadening, chemical shift considerations and off-resonance decoupling.
Oxidation of Alkoxyphenols. XXV Crystal Structures of 4,6-Di-t-butyl-4a-hydroxy-8-methoxydibenzofuran-2(4aH)-one-Chloroform and 3',4,9'-Tri-t-butyl-2',5,10'-trimethoxyspiro[cyclohexa-3,5-diene-1,6'-dibenzo[d,f][1,3]dioxepin]-2-one
Authors: Hewgill FR , Raston CL , White AH
Published: September 2010

Crystal structures of the
title compounds have been determined, thus confirming the original assignments.
The Chemistry of α'-Trifluoroacetamido α-Diazoketones
Authors: Blair IA , Mander LN
Published: September 2010

2-Amino-8-methoxy-l,2,3,4-tetrahydro-2-naphthoic
acid hydrochloride (6) was converted into its trifluoroacetamide (8) and the
reaction of its 1,3-oxazolone (7) with diazomethane studied. The major product
from this reaction was shown to be the α'-trifluoroacetamido α-diazoketone
(11), the minor products were identified as the 1,3-oxazine (14) and the
1,3-oxazepine (13). The acid-catalysed cyclization of the diazoketone (11)
provided a dienone (16) in modest yield. The route to key substrates for the
synthesis of gibberellins with potential C13 nitrogen functions was thus
demonstrated. The reaction of two other oxazolones (25) and (28) and a pseudo-oxazolone
(17) with diazomethane was investigated and the necessity for a strong
electron-withdrawing group attached to the oxazolone ring demonstrated. The
photochemical Wolff rearrangement of diazoketone (20) provided a homologated
phenylalanine derivative (21). The reaction of an indanyloxazolone (25) with
diazomethane furnished the corresponding diazoketone (26) in high yield.
Stereochemical Studies. V. Structure of the 'Hydroxymethylene Derivative' Obtained from trans-Decahydronaphthalen-1-one. A Spectroscopic Study
Authors: Lewis PH , Middleton S , Rosser MJ , Stock LE
Published: September 2010

Formylation of trans-decahydronaphthalen-1-one
gives a 'hydroxymethylene derivative' which is, in
reality, a complex mixture of stereoisomeric and
tautomeric structures; stereochemical integrity at
the ring junction is lost during the reaction. The same 'derivative' is
obtained on formylation of the isomeric cis-ketone.
Crystal Structure of Methanethiolatomercury(II) Chloride
Authors: Canty AJ , Raston CL , White AH
Published: September 2010

The crystal structure of
the title compound, MeSHgCl, has been determined by
single-crystal X-ray diffraction at 295 K and refined by full-matrix least
squares to a residual of 0.048 for 787 'observed' reflections. Crystals are
monoclinic, P21/c, a
7.490(4), b 7.395(2), c 7.815(3) �,β
92.93(4)�, Z 4, and are isostructural with the
previously described MeSHgBr.
59Co and 13C Nuclear Spin Relaxation Studies in Solutions of Symmetric, Bidentate Cobalt(III) Complexes. On the Mechanism of 59Co Spin Relaxation. Crystal Structure Determination of Tris(tropolonato)cobalt(III)
Authors: Doddrell DM , Bendall MR , Healy PC , Smith G , Kennard CHL , Raston CL , White AH
Published: September 2010

Valiev's suggestion of excitation of the vibrational modes of
the octahedron is considered as a spin relaxation mechanism for 59Co
spins in some symmetric, bidentate CoIII complexes. His theory is
extended to the spin 7/2 system; the efficiency of the mechanism is very
sensitive to the molecular size with larger complexes having much shorter T1
values. Experimental evidence in support of the mechanism is provided by the
contradictory values of quadrupole coupling constants calculated experimentally
by assuming rotational reorientation to be the dominant time process and by
measurements on a variety of CoIII complexes. Rotational correlation
times were measured from 13C T1 values of protonated carbons in the complex. An X-ray structure
determination of tris(tropolonato)-cobalt(III) is
reported in support of the suggested relaxation mechanism. The differences
between T1 and T2 in some CoN6 complexes are
shown to arise from unresolved 59Co-14N scalar coupling.
Chiral Shielding in Nuclear Magnetic Resonance Spectroscopy
Authors: Stiles PJ
Published: September 2010

A novel van der Waals shielding mechanism is
discussed which contributes to the magnetic shielding non-equivalence of
optical isomers of one chiral species in the presence
of a second optically active species. It is more direct than standard
mechanisms which invoke stereospecific association of the interacting molecules
but appears to be of marginal experimental significance.
A Nuclear Magnetic Resonance Study of Water + Acetonitrile Mixtures
Authors: Easteal AJ
Published: September 2010

Water proton chemical
shifts at 308 K and CN-group 13C chemical shifts at 300 K, relative
to methyl protons and methyl carbon respectively, have been determined as a
function of composition for the water + acetonitrile system. The composition
variation of the water proton shift, particularly, suggests that in this system
there may be as many as five structurally distinct composition regions, whose
possible structures are discussed. This system appears to be more similar to
systems like water + dioxan than to most other water + organic solvent systems,
except for the complexity of the structural discontinuities in the water +
acetonitrile system.
The Effect of Steric Hindrance on Radical and Ionic Substitution Reactions of Nucleophiles with Some α-Alkyl-p-Nitrobenzyl Chlorides
Authors: Norris RK , Randles D
Published: September 2010

The reactions of the α-alkyl p-nitrobenzyl chlorides, p-NO2C6H4CH(CI)R(R
= Me, Pr1, But), with nucleophiles, e.g, nitrite,
nitroethanide, benzenethiolate and p-toluenesulfinate
ions and the anion derived from diethyl 2-methylmalonate, in dimethyl sulfoxide
have been studied. When R = But, SRNl reactions take
place and give, in the reaction with p-toluenesulfinate
and the anion from diethyl 2-methylmalonate, extremely sterically crowded
molecules, which, as a result of bond formation between the more hindered atom
in the ambident nucleophile and the benzylic carbon, display dynamic 1H
N.M.R. effects. The derivatives where R = Me or Pri undergo radical
and/or ionic processes depending on the nucleophile being used. Pathways
accounting for some of the unusual compounds produced, e.g. 5-methyl-3,5-bis(p-nitropheny1)-2-isoxazoline N-oxide and
(E)- and (Z)-p-nitroiso-butyrophenone
O-(p-nitrobenzoyl) oximes from reaction of nitrite ion with the α-methyl and α- isopropyl compounds respectively, are proposed.
Isomerizations Akin to the Dimroth Rearrangement. V. Bis-s-triazolo[4,3-α:4',3'-c]pyrimidines and Related Systems
Authors: Brown DJ , Nagamatsu T
Published: September 2010

Synthetic routes to the
parent compounds and/or simple methylated derivatives of bis-s-triazolo[4,3-a:4',3'-c]pyrimidine (1),
bis-s-triazolo[l,S-a:4',3'-clpyrimidine
(2) and bis-s-triazolo[4,3-a:1',5-c]-
pyrimidine (3) are reported. Structures are confirmed by unambiguous syntheses
and/or N.M.R. spectral comparisons with known s-triazolo[4,3-a]pyrimidines
and their [1,5-a], [4,3-c] and [1,5-c] isomers. Several ill-based structural assignments in the
literature are corrected or confirmed. The systems (1)-(3) are unexpectedly
stable towards rearrangement in acid or alkali but system (1) does undergo a
thermal Dimroth-like rearrangement into system (2). Attempts to prepare an
abnormal bis-s-triazolopyrimidine,
e.g. (13), from pyrimidine-4,6-diyldihydrazine (12a) are shown to yield only
intermediates for, or a degradation product from, the postulated system.
Transition Metal Complexes of 5-(Pyridin-2-yl)tetrazole and Methyl-Substituted 5-(Pyridin-2-yl)tetrazoles
Authors: Gill NS , Yang F
Published: September 2010

Transition metal complexes
of the formulae M(ptt)2,2H2O (M = Mn, Fe, Co, Cu, Zn),
M(ptt)2,- 2NH3,H2O (M = Co, Ni),
FeCl(ptt),2H2O, Ag(ptt), Mn(tmptt)2,2H2O M(tmptt)2,NH3,2H2O
(M = Cu, Zn)M(tmptt)2NH32H2O (M=Co, Ni), Ni(tmptt)2,2NH3,H2O,
Ag(tmptt), M(smptt)2 (M = Co, Ni), Cu(smptt)2,3H2O,
Cu(smptt)2,NH3,2H2O, Cu(smptt)2,2NH3,
Zn(smptt)2,NH3,H2O and Ag(smptt) where ptt,
tmptt and smptt are the anions of 5-(pyridin-2-yl)tetrazole,
5-(3-methylpyridin- 2-yl)tetrazole and 5-(6-methylpyridin-2 yl)tetrazole,
respectively, have been prepared.Studies of the infrared and
ultraviolet-visible spectra, magnetic moments and X-ray diffraction patterns
show structural relationships between compounds and indicate that, in addition
to the organic ligands, water and ammonia molecules are bonded to the metal
ions. Thermal decomposition of the compounds proceeds through the formation of
pyridinecarbonitriles.
Oxidative Decarboxylation of Some Bicyclo[4,1,0]hept-3-ene-1,6-dicarboxylic Acids
Authors: Galloway N , Halton B
Published: September 2010

Treatment of the
bicyclo[4,1,0]hept-3-ene-1,6-dicarboxylic acids (6d-f) with lead tetraacetate
under a variety of conditions results in oxidative decarboxylation and
formation of the isobenzofuranl(3H)-ones (9a-c) and (10c). In addition, the
corresponding acid anhydrides (7a-c) are formed and these are resistant to
oxidative decarboxylation.
Oxidations with Lead Tetraacetate. I. Oxidations of Naphthalene Ethers
Authors: Cole ER , Crank G , Stapleton BJ
Published: September 2010

Oxidations of 1- and
2-methoxy-, and 1,5- and 2,6-dimethoxy-naphthalene were performed thermally and
photochemically with various oxidant/reactant ratios. A wide variety of
products including acetoxy derivatives, dimers, o- and p-quinones
(monomeric, dimeric and polymeric) and polysubstituted derivatives were formed
demonstrating the high reactivity of naphthalene ethers. Higher ratios of
oxidant gave increased yields of quinones, but photochemical reactions gave
virtually the same mixtures of products as thermal processes. The position of
the methoxy group controlled the initial attack by the reagent: for 1-methoxy-
and 1,5-dimethoxy-naphthalene the 4-position is the site of reaction, while for
2-methoxy- and 2,6-dimethoxy-naphthalene position 1 reacts. Results indicate
that initial products are further oxidized to the more complex structures
found. Several different mechanistic paths are required to explain the variety
of products.
Colouring Matters of Australian Plants. XXI. Naphthoxanthenones in the Haemodoraceae
Authors: Cooke RG , Dagley IJ
Published: September 2010

Two new pigments,
haemofluorone A and haemofluorone B, have been isolated from the flowers of Macropidia fuliginosa Drum. and also
from the root system of Phlebocarya
ciliata R.Br. Spectroscopic analysis indicates the structures 5,8,9- and
8,9,11-trihydroxy-lH-naphtho[2,1,8-mna]xanthen-l-one. The former structure
has been confirmed by a synthesis of the trimethyl ether by photochemical oxidative
cyclization of 9-(3,4-dimethoxyphenyl)-6-hydroxy-2-methoxy-1H-phenalen-1-one.The parent chromophore, 1H-naphtho[2,1,8-mnalxanthen-1-one, and
the 2,5-dimethoxy derivative have also been prepared by analogous photochemical
reactions of the appropriate arylphenalenones.
Insect Moulting Hormones: A Study of 4-En-3-one Steroids as Possible Ecdysteroid Precursors.
Authors: Kinnear J , Martin M , Faux A , Horn DS , Wilkie J
Published: September 2010

The trienol ether (15) of
cholesta-4,7-dien-3-one (4) is oxidized with peroxy acid mainly to the
6-hydroxy derivatives (6) and (7) and the corresponding
cholesta-4,7-diene-3,6-dione (8). However, the biosynthesis of ecdysteroids may
not proceed by a similar pathway since the labelled keto diene (5) was not
incorporated into 20-hydroxyecdysone (10) in Calliphora stygia. None of the possible 4-en-3-one ecdysteroid
precursors synthesized (6), (7), (8), (18) were active in the Calliphora assay.
The Chemistry of Eremophila spp. XI. The Absolute Configuration of Dihydroxyserrulatic Acid
Authors: Croft KD , Ghisalberti EL , Jefferies PR , Stuart AD
Published: September 2010

Dihydroxyserrulatic acid (1),
a diterpene from Eremophila serrulata,
has been degraded to the naphthalene (2) which was shown to have the R-configuration. The diterpene acid can
now be designated as (5R,8S,1'S)-4-hydroxy-8-(6'-hydroxy-1',5'-dimethylhex-4-enyl)-5-methyl-5,6,7,8-tetrahydronaphthalene-2-carboxylic
acid.
The Microwave Spectrum of Vinylketene
Authors: Brown RD , Godfrey PD , Woodruff M
Published: September 2010

We have generated trans-vinylketene by pyrolysis of vinylacetic anhydride and measured and
assigned its microwave spectrum. From the derived rotational constants the inertial defect is
estimated to be 0.04 uǺ2 (700 × kg m2), which indicates a planar molecule. This, together
with infrared and mass spectral data, identifies the compound as vinylketene rather than any of
its isomers. We have confirmed that vinylketene is also produced by pyrolysis of 1-ethoxybut-3-en-
1-yne, but have found that it is not produced by the pyrolysis of 5-ethylidene-2,2-dimethyl-1,3-dioxan-
4,6-dione.
The dipole moment of vinylketene is 0.97 D (3.24 × 10-30 C m). An explanation of its lower
magnitude as compared with other carbonyl compounds is offered in terms of π-electron delocalization.
Crystal Structure of Ethyltriphenylphosphonium Bis(α,α,α',α'-tetracyanoquinodimethanide)
Authors: Fleming RJ , Shaikh MA , Skelton BW , White AH
Published: September 2010

The crystal structure of
the title compound, [EtPh3P]+
[(C12H4N4)2]-, has been
established by single-crystal X-ray diffraction methods at 295(1) K and refined
by least squares to a residual of 0�039 for 3047 'observed' reflections.
Crystals are triclinic, Pī, a 8 �882(7),
b 13�522(5), c 15�927(6) �, α 75�34(3), β
96�69(5), γ 100.56(3)�, Z 2. The structure closely resembles that of the
methyl-triphenyl-phosphonium and -arsonium analogues, containing tetrads of α,α,α',α'- tetracyanoquino- dimethane*
molecules, the molecular planes lying parallel to each other and approximately
normal to b.
The N-Alkylation and N-Arylation of Unsymmetrical Pyrazoles
Authors: Grimmett MR , Lim KHR , Weavers RT
Published: September 2010

Unsymmetrical pyrazoles
with alkyl, aryl, nitro and carboxyl substituents at C3 or C5 have been
methylated with dimethyl sulfate in methanol, dimethyl sulfate in basic medium,
and with diazomethane. The ratios of the isomeric N-methylpyrazoles have been determined by N.M.R. and g.l.c.
analysis. The modified Ullmann phenylation has also been applied to these
pyrazoles. Explanations for the observed product orientations involve
considerations of electronic and steric effects, the possible intermediacy of
quaternary salts, and, in some instances, the likelihood that the dominant
tautomer is reacting.
Dehydration Studies of r-4-Chloro-8a-methyl-trans- and cis-decahydronaphthalen-t-4a-ols
Authors: Coxon JM , Gibson JR
Published: September 2010

Electron-withdrawing
substituents at C4 in 8a-methyl-trans-decahydronaphthalen-4a-ol
allow methyl migration to compete with 1,2-elimination in H2SO4/HOAc/Ac2O
media but not in SOCl2/ pyridine. Under both these reaction
conditions for 4-substituted 8a-methyl-cis-decahydronaphthalen-
4a-ols methyl migration does not compete with 1,2-elimination.
The Influence of the Chlorine Substituent in Some Addition Reactions of 1-Chloronorbornene
Authors: Della EW , Reimerink MP , Wright BG
Published: September 2010

The products of
electrophilic addition of mercuric acetate, chromyl chloride and nitrosyl
chloride to 1-chloronorbornene (4) have been investigated. While the rate of
addition is slower than that of norbornene, the magnitude of the directive
effect of the chlorine is found to vary significantly from case to case. Thus
high regiospecificity is observed in oxymercuration-demercuration, moderate
regiospecificity in the addition of nitrosyl chloride, and only minor
preference of attachment in chromyl chloride oxidation. High stereospecificity
is noted in all cases.
Synthesis of N-Acetyl-S-trifluoro-methylphenyl-DL-cysteine Esters
Authors: Ondrus TA , Christie BJ , Guy RW
Published: September 2010

A new general method for
the synthesis of N-acetyl-S-trifluoromethylphenyl-DL-cysteine
methyl esters has been developed as part of a continuing study of the metabolism
of trifluoromethyl-substituted aromatic compounds.
Prediction of the Absolute Configurations of the Enantiomers of Racemic Primary and Secondary Alcohols and Primary Amines by Kinetic Resolution with (2R,3R)-2,3-Diacetoxysuccinic Anhydride
Authors: Bell KH
Published: September 2010

The absolute configurations
of the enantiomers of a variety of racemic secondary and primary alcohols and racemic primary amines have been correctly predicted from
the results of kinetic resolution with (2R,3R)-2,3-diacetoxysuccinic anhydride.
In the prediction model (1), allocation of relative sizes to the groups
attached to the chiral centre was based on conformational free energy
differences.
Purine Studies. XXII. Occurrence of N- and C-Methylation on Diazomethane Treatment of 2-Methylthiopurine
Authors: Lister JH
Published: September 2010

Diazomethane treatment of
2-methylthiopurine gives the expected 9- methyl-2-methylthiopurine as the main
product together with a smaller amount of the 7-methyl isomer. An unexpected
feature of this reaction, however, is the formation also, in smaller but significant
yields, of C,N-dimethylated homologues, identified as 7,8- and 8,9-dimethyl-2- methylthiopurine.
Subsequent methylation studies point towards the 8-methyl group in the latter
derivatives being introduced prior to the N-methylation step, thus representing
an additional alkylation pathway for some purine derivatives.
An Alternative Method for the Preparation of Cyclic Sulfides
Authors: Crumbie RL , Ridley DD
Published: September 2010

The reactions of α,ω-dihaloalkanes with one equivalent of thiourea
have been investigated. Certain ω-chloro-α-iodoalkanes give
satisfactory yields of ω-chloroalkylisothiouronium
iodides which on hydrolysis directly afford cyclic sulfides.
Electron-transfer fluorescence quenching by aliphatic amines
Authors: Watkins AR
Published: September 2010

Electron-transfer
interaction of an excited aromatic molecule with an aliphatic tertiary amine
leads to a pattern of intermediate products not to be expected from earlier
work with aromatic amines. The reasons for this phenomenon are briefly
discussed.
Reactions between ruthenium chlorides and trimethyl phosphite : crystal and molecular structures of RuCI3(NH3)[P(OMe)3]2
Authors: Bruce MI , Kelly DA , Mclaughlin GM , Robertson GB , Tomkins IB , Wallis RC
Published: September 2010

The reaction between RuCl3,nH2O
and P(OMe)3 affords RuCl2[P(OMe)3]4;
one batch of RuCl3,-nH2O also gave
amminetrichlorobis(trimethyl phosphite)ruthenium(III), RuCl3(NH3)[P(OMe)3]2,
as a minor product. The structure of this complex has been determined from a
single-crystal X-ray diffraction study (4598 data, R 0.065, Rw 0.090): the
ruthenium is approximately octahedrally coordinated by the three mer chloro,
two trans P(OMe)3 and one NH3 ligands. Crystals are
monoclinic,P21/n, a 8.725(3), b 18.286(7), c 10.936(4)Ǻ, β
94.57(3)°, Z 4.
Identification of the iridoid glucoside theveside in Lantana camara (Verbenaceae), and determination of its structure and stereochemistry by means of N.M.R.
Authors: Ford CW , Bendall MR
Published: September 2010

The iridoid glucoside
theveside has been isolated from the leaves and stems of three taxa of Lantana camara (Verbenaceae), where it
occurs as the sodium salt. Elucidation of the structure was primarily from 1H
and 13C n.m.r. spectra. The stereochemistry of the molecule was
established from 1H homonuclear decoupling
and Overhauser enhancement experiments. Theveside may now be fully described by
the systematic name [1S- (1α,4aα,7aα)]-1-(β-D-glucosyloxy)-4a-hydroxy-7-(hydroxy-methyl)- 1,4a,5,7a-tetrahydrocyclopenta[c]pyran-4-carboxylic
acid. Theveside, already found in two members of the Apocynaceae, is previously
unreported in the Verbenaceae.
The chemistry of pyrrolic compounds. XLV. Haematoporphyrin derivative: haematoporphyrin diacetate as the main product of the reaction of haematoporphyrin with a mixture of acetic and sulfuric acids
Authors: Clezy PS , Hai TT , Henderson RW , Thuc LV
Published: September 2010

A mixture of acetic and
sulfuric acids converts haematoporphyrin into a complex mixture of porphyrins
of which the main product has been characterized as the diacetate (1g). Other
compounds identified in the reaction mixture were the known vinylporphyrins (1b-d),
(1h) and (li) and the isomeric monoacetoxyethyl(monohydroxyethyl)porphyrins
(11) and (1m). Analysis of the reaction mixture was complicated by the presence
of 1'-ethoxyethyl derivatives (1e) or (1f), (1j) and (1k)which presumably arose
by solvolysis of the corresponding acetate with ethanol present in the chloroform
used for the chromatographic separation.
The density, viscosity and transference number of aqueous cobalt chloride at 298.15 K
Authors: Phang S
Published: September 2010

The density, viscosity and
transference number of aqueous cobalt(II) chloride at 298.15 K over the concentration
range of 0.1-4.0 mol kg-1 are reported. The transference number was
measured by the e.m.f. method. The transference number of the cobalt ion constituent
was found to be constant above about 3 mol kg-1.
Effects of substituents on ion-association properties. 1H n.m.r. studies of substituted pyridinium tribromo(triphenylphosphine)cobaltate(II) complexes in nitrobenzene
Authors: Tsao N , Lim Y
Published: September 2010

A series of compounds
containing substituted pyridinium cations and the tribromo(triphenyl-phosphine)cobaltate(II)
complex anion have been prepared and studied by n.m.r. spectroscopy in nitrobenzene
at 307 K. It is shown that the electronic and the steric effects of the
substituents can affect the ion-association constant. From the measured
isotropic shift ratios, it is concluded that two substituents at the meta
positions of the pyridine ring move the complex anion away from the ring,
whereas a para substituent tends to favour a geometry where the anion is tilted
towards the ring.
The reactivity of p-nitrophenyl esters with surfactants in nonaqueous solvents. II. The effects of added water in benzene solutions of dodecylammonium propionate, and the reaction in toluene and cyclohexane
Authors: O'Conner CJ , Ramage RE
Published: September 2010

The rate of decomposition
of p-nitrophenyl acetate, pnpa, in benzene containing
up to 0.11 mol dm-3 of solubilized water in the presence of dodecylammonium propionate, dap, has been measured at 298
K. Although the micellar rate constant is decreased due to hydration of the
head- groups, the bimolecular rate constant due to general acid-general base
catalysis from the head-group components of dap is unchanged. There is no
evidence to suggest that the substrate undergoes hydrolysis. Changing the
solvent to either toluene or cyclohexane increases the micellar rate constant
and changes the second term in the rate equation to one which includes the
square of the surfactant concentration.
Orbital interactions. IX. The effect of remote substituents on the electrophilic nitration of a series of 11-substituted exo-hexahydro-7,10-methanofluoranthenes
Authors: Oliver MJ , Patney HK , Paddon-Row MN
Published: September 2010

Product distribution and
the relative rates of nitration (Cu(NO3)2,3H2O/Ac2O) of a series of
11-substituted exo-hexahydro-7,10- methanofluoranthenes,
(8), (9b), (10) and (11b), and acenaphthene, (12), have been determined. It was
observed that a syn-methoxy substituent, as in (11b), greatly enhanced the
reactivity of the acenaphthene ring towards nitration compared with unsubstituted
(8), the α position being activated more than the γ position.
Precisely the opposite result was obtained for the nitration of the ketone
(10). These results are explained in terms of the consequences of through-
space orbital interactions (OITS), operating between the molecular orbitals of
the 11-substituent and those of the acenaphthene ring; a PMO model is used for
the nitration reaction. The results of INDO MO SCF calculations on the
water-acenaphthene complex (22) and the formaldehyde-acenaphthene complex (23),
which are intended to mimic the salient features of (11b) and (10)
respectively, lend support to the OITS proposal. However, alternative
proposals, based on field effects (in the case of (10)) and on the formation of
a complex (24) for the nitration of (11b), are also discussed.
Cyclophanes. XV. The synthesis of [2,2](3,3',4,4')biphenylophanes and their conformational mobility
Authors: Leach DN , Reiss JA
Published: September 2010

The [2,3](3,3?,4,4?)biphenylophanes
(10) and (14) have been synthesized by using standard ring-contraction procedures
from the dithiacyclophane (7). Both of these cyclophanes were found to be conformationally
mobile and the activation energy barriers for ring-flipping for compounds
(10)and (14) have been calculated to be ΔG‡c (213 K)
43.5�2 kJ mol-1 (10.4�0.5 kcal mol-1) and ΔG‡c
(261 K) 53.1�2 kJ mol-1 (12.7�0.5 kcal mol- 1)
respectively. The similarity of these values indicates that, in these large
macrocycles, any steric effects arising from differences in bond angles and
bond lengths of the bridging functions have been effectively minimized. Both
compounds (10)and (14) are considered to undergo conformational ring-flipping
by either a concerted disrotation of the two constituent benzene rings in the
3,3′-biphenyl moiety, or a stepwise rotation involving two discrete steps.
Terpenoid chemistry. XXIV. (1R)-1-Methoxymyodesert-3-ene, an Iridoid Constitutent of Myoporum deserti (Myoporaceae)
Authors: Grant HG , O'Regan PJ , Park RJ , Sutherland MD
Published: September 2010

A common variety of Myoporum
deserti A. Cunn. (Ellangowan
Poison Bush) yields an essential oil consisting largely of the iridoid
monoterpene, (1R)-1-methoxymyodesert-3-ene, C11H18O2,(1R,4aS,7R,7aR)-1-methoxy-4,7-
dimethyl-1,4a,5,6,7,7a-hexahydrocycopenta[c]pyran, b.p.
67°/2 mm,[α]D- 165°. This cyclic acetal is hydrolysed to methanol and a
mixture of two epimeric cyclopentanoid dialdehydes which are oxidized to the
two epimeric trans,trans-nepetalinic acids and yield
(+)-(R)-actinidine with Brady's reagent. (1R)-1-Methoxymyodesert-3-ene is
oxidized by ozone/hydrogen peroxide to (1R,2R,5R)-2-acetyl-5- methylcyclopentanecarboxylic acid. Hydrogenation yields mainly
(1R)- methoxymyodesertan, hydrolysed by aqueous maleic acid at room temperature
to methanol and a cyclic hemiacetal, (1R,4R,4aR,7R,7aR)- 4,7-dimethyl-1,3,4,4a,5,6,7,7a-octahydrocyclopenta[c]pyran-1-ol.
Oxidation of this cis,cis-hemiacetal by bromine in
acetate buffer yields a lactone further oxidized by chromic acid to
(2R,1'S,2'R,3'R)- 2-(2'-carboxy-3'-methylcyclopentyl)-propionic acid.���
(1R)-1-Methoxymyodesertan, refluxed with
aqueous phthalic acid, yields (+)-(4R,4aR,7R)-4,7-dimethyl-3,4,4a,5,6,7-hexahydrocyclopenta[c]pyran. Treatment of the
hexahydropenta[c]pyran, the cis,cis-hemiacetal or
(1R)-1-methoxymyodesertan with hydrochloric acid yields a trans,trans-hemiacetal,
(1R,4R,4aR,7R,7aS)-4,7-dimethyl- 1,3,4,4a,5,6,7,7a-octahydrocyclopenta[c]pyran-1-ol,
which equilibrates in solution to a mixture of α- and β-anomers. Spectral studies of these and otherproducts
establish the configuration of the natural product at C1.���
(1R)-1-Methoxymyodesert-3-ene is not toxic
to sheep as are the β- substituted furans characteristic of most other
chemovarieties of M. deserti.
Free-radical reductions of arenediazonium ions in aqueous solution. IV. Kinetics of reactions of para-substituted diazonium ions with benzyl alcohol, isopropyl alcohol and methanol
Authors: Packer JE , Heighway CJ , Miller HM , Dobson BC
Published: September 2010

Electron-withdrawing
substituents are shown to increase the chain length of free-radical hydro-dediazoniation
reactions, but the actual reaction step causing the substituent effect depends
on the relative rates of propagation and termination reactions. With benzyl
alcohol as reducing agent the rate of the slow propagation step is increased,
while with isopropyl alcohol the rate of the termination step is decreased.
Rate constants for some reactions of radicals with diazonium ions are reported,
and the nature of some of these reactions and their implication for an
understanding of the homolysis of aromatic diazo compounds are discussed.
Preparation of the 2,3-anhydro-4,6-O-benzylidene derivatives of methyl α- and β-D-talopyranoside and of methyl α-D-gulopyranoside
Authors: Frahn JL
Published: September 2010

Instructions are given for
preparing the title compounds in reproducibly good yields from the appropriate
anomer of methyl 4,6-O-benzylidene-2,3-di-O-tosyl-D-galactopyranoside. The
α-anomer is converted into a mixture of the anhydro-α-taloside and
anhydro-α- guloside by reaction with sodium methoxide in dimethyl
sulfoxide as solvent at room temperature. The β-anomer forms the
anhydro-β-taloside under similar conditions but with dioxan as solvent for
the reactants.
The crystal structure of Tetraisothiocyanatotetrakis(tetramethylurea)thorium(IV)
Authors: Rickard CEF , Woollard DC
Published: September 2010

The structure of the title
complex has been determined by single- crystal X-ray crystallography. The
crystals are monoclinic, a 13.954(1), b 20.334(2), c 14.138(1) Ǻ, β
98.06(3)°, space group P21/c. The structure was refined to a
residual of 0.044 by using 3875 structure amplitudes. The molecules are
eight-coordinate, the coordination polyhedron being a slightly distorted
dodecahedron with the oxygen and nitrogen donor atoms equally distributed
between the A and B sites.
(4R)-Thiazolidine-4-carboxylic acid: ligand specificity and the synthesis and X-ray structure of a cobalt(III) complex
Authors: Gainsford GJ , Jackson WG , Sargeson AM , Watson AD
Published: September 2010

The N,O mode of bonding of
the thiazolidine-4-carboxylate ligand and the structure of the Δ-bis-(ethane-1,2-diamine)[(3R,4R)-thiazolidine-4-
carboxylato-N,O]cobalt(2+) ion have been determined. The stereospecificity
induced by the chiral amino acid between the A and A forms is discussed in
relation to analogous proline chemistry.
Some metal-ion complexes with ligands formed by reactions of amines with aliphatic carbonyl compounds. IX. Nickel(II) compounds of some b-imino amines, a β-oximato amine and a β-hydrazino amine
Authors: Morgan KR , Curtis NF
Published: September 2010

Singlet ground state
compounds of nickel(II) with tetradentate β-imino
amine ligands are formed by reaction of complexes of ethane-1,2- diamine, propane-1,2-diamine,
3-azapentane-1,5-diamine, 4-azaheptane- 1,7-diamine and (2-aminoethyl)piperazine
with 4-amino-4-methylpentan-2- one, amp. With 3,6-diazaoctane-1,8-diamine, a
compound with a pentadentate β-imino ligand is formed, water completing
octahedral coordination, and with 2-aminoethanol a bis compound of a tridentate
β-imino amine alcohol ligand is formed. More complex products are formed
by the hydrazone and oxime of amp. The oxime compound shows appreciable
antiferromagnetism, with the spin-coupling constant, J, about -70 cm-1,
determined from magnetic susceptibility measurements over 100-300 K.
Dehydrogenation of 3-carene in the vapour phase. II. Performance studies of chromia and chromia-alumina catalysts
Authors: Krishnasamy V
Published: September 2010

The influence of contact
time on the dehydrogenation of 3-carene over reduced chromia and
chromia-alumina catalysts has been investigated at 450 and 400°C respectively.
For the dehydrogenation, reduced chromia- alumina catalyst is more active than
reduced chromia alone. It has been found that the dehydrogenating ability of
reduced chromia is superior to that of oxidized chromia. The effect of water
vapour on reduced chromia showed an initial suppression of its reactivity, but
at intermediate values increased its activity. Progressive increase of water
vapour was seen to modify the active sites of reduced chromia, an effect
similar to that of the oxidized sample. ��� The dehydrogenation of 3-carene, over
chromia, follows second-order kinetics. The energy of activation is found to be
greater for oxidized than for reduced chromia. Impregnation of chromia with
potassium decreases the activation energy of reduced chromia and enhances its
dehydrogenation ability by suppressing the side reactions. ��� The observed experimental data are
explained in terms of the acidity of the catalysts, oxidation states of
chromium ions and the promoting influence of potassium ions.
Crystal and molecular structure of a platinum(0) complex of cyclooctyne
Authors: Robertson GB , Whimp PO
Published: September 2010

The crystal and molecular
structure of a platinum(0) complex of cyclooctyne, [(coct)Pt(PPh3)2],
has been determined from three- dimensional X-ray data collected by counter
methods. The complex crystallizes in the space group P21/n [a
non-standard setting of space group P21/c (C2h5,
No. 14)], with a 20.660(9), b 12.299(5), c 15.470(7) Ǻ, β 110.26(2)°,
Z 4. The structure was solved by conventional Patterson and Fourier methods and
was refined by block-diagonal least-squares techniques to weighted and unweighted
R-factors of 0.048 and 0.047 respectively, for the 4733 unique reflections with
I/σ(I) ≥ 3.0. The molecule is essentially square planar about the
'central' platinum atom, with the triphenylphosphine groups occupying cis
coordination sites. The Pt-C distances are equal within experimental error
[2.034(9) and 2.037(9) Ǻ] and compare favourably with the corresponding
distances in the platinum(0)-cyclohexyne and -cycloheptyne analogues. The
acetylenic C=C distance is 1.279(13) Ǻ and shows the normal bond
lengthening consequent upon coordination.
Metal-catalysed exchange of alkyl and silyl hydrogen in organosilanes with tritium gas over Raney nickel as measured by 3H N.M.R
Authors: Long MA , Garnett JL , Lukey CA , Williams PG
Published: September 2010

Analysis by tritium n.m.r,
of triethylsilane, tetramethylsilane, hexamethyldisiloxane and chlorodimethylsilane exchanged with tritium gas over Raney
nickel at 100°C shows that exchange readily occurs in alkyl substituents as
well as with silyl hydrogen; novel species involving charge-transfer
intermediates in dissociative adsorption at the C-H
as well as the Si-H bonds are proposed to explain the
data.
An extension of the linear relationship between molecular rotation and bond refraction
Authors: Poh B
Published: September 2010

The usefulness of the
empirical equation [M]D = mΣRD+I, first proposed by
Davis and Jensen, in the correlations of the molecular rotations of
series of structurally closely related compounds was originally limited to
monovalent and linear substituents ([M]D is the molecular rotation,
ΣRD is the sum of bond refractions, and m and I are constants
for a given series of compounds). A different treatment of the term ΣRD
extends the usefulness of the equation to all types of substituents.
High-pressure photodimerization of a naphthalene derivative
Authors: Hamann SD , Linton M , Sasse WHF
Published: September 2010

An applied pressure of 2000
bars (1 bar = 105 Pa ≡ 0.9869 atm)
has been found to double the rate of photodimerization of methyl 3-methoxy-2- naphthoate in solution in toluene and in methanol at 20°C.
The acceleration corresponds to an average activation volume between 1 and 2000
bars of ΔV‡av ≈ -10 cm3 mol-1, and
is much less than the known acceleration, under similar conditions, of
analogous thermal reactions.
Formation constants for magnesium and calcium citrate complexes
Authors: Pearce KN
Published: September 2010

centration formation
constants for magnesium and calcium citrate complexes have been redetermined from pH titrations of citric acid in the
absence and presence of the divalent metal ions in aqueous solution at 2°
Values for the constants, corrected for the presence of potassium citrate
complex, are presented and critically compared with literature values. Values
for the formation constants of strontium and barium citrate complexes are also
reported.
Structure and bonding in the neutral and anionic forms of dimethylglyoxime and its complexes
Authors: Raston CL , Skelton BW , White AH
Published: September 2010

In order to permit a
comparative study of the structure and bonding behaviour of dimethylglyoxime in
its neutral and monoanionic forms, both 'free' and complexed to transition
metals, redeterminations of the crystal structures of dimethylglyoxime, dmgH2,
and the complexes Cu(dmgH2)Cl2 and Cu(dmgH2)Br2
have been carried out, together with an initial determination of the structure
of the hydrated sodium salt Na2(dmg),8H2O. Crystals of
dmgH2 are triclinic, space group Pī, a 6.078(3), b 6.319(3), c
4.492(2) Ǻ, α 122.69(3), β 91.71(4), γ 77.72(4)°, Z 1 the
structure was refined to a residual of 0.049 for 748 'observed' reflections.
Crystals of Na2(dmg),8H2O are monoclinic, P21/c,
a 11.317(7), b 12.995(7), c 4.901(4) Ǻ, β 100.55(5)°, Z 2, the
structure being refined to a residual of 0.040 for 942 ?observed? reflections.
Crystals of Cu(dmgH2)Cl2 are triclinic, Pī, a 8.163(4),
b 8.109(3), c 7.701(2) Ǻ, α 110.88(3), β 101.31(3), γ
108.04(3)°, Z 2; for the isomorphous bromide a 8.628(3), b 8.276(4), c 7.757(2)
Ǻ, α 111.18(3), β 101.02(3), γ 108.55(3)°. The two
structures were refined to residuals of 0.052 and 0.045 for 964 and 1597
'observed' reflections respectively.
Copper-catalysed reaction of 2-chloroimidazoles and 2-chlorobenzimidazoles with dimethylamine
Authors: Whittle CP
Published: September 2010

The preparation of 2-dimethylamino-benzimidazoles
and -imidazoles from the corresponding 2-chloro
compounds by reaction with dimethylamine is assisted by the presence of copper
salts. In the absence of a copper catalyst, 2-chloroimidazoles fail to react. Kinetic
studies indicate a mechanistic relationship to other copper-catalysed reactions
for which arylcopper(I) intermediates have been proposed.
Tetranuclear carbonylfluorohydroxymanganese(I) clusters, [Mn4(CO)3Fx(OH)4-x]
Authors: Horn E , Snow MR , Zeleny PC
Published: September 2010

Reactions of Mn(CO)5X(X = Cl, Br)
with TIF or AgF in dichloromethane solution give the
cluster species [Mn4(CO)12Fx(OH)4-x].
The TlF reactions give predominantly the species with
x = 1 and 2 and the AgF reaction the species with x =
2 and 3. The individual species x = 0-4 can be identified in the mass spectrum.
The x = 2 product from the AgF abstraction can be
separated from the x = 3 one by crystallization over benzene to yield the pure
solvate [Mn4(CO)12F2(OH)2],-2C6H6.
The infrared OH stretch in this compound (3543 cm-1) shifts to
higher frequency (3620 cm-1) on desolvation (100�C, 0.1 mmHg),
confirming OH...π hydrogen bonding to benzene, and explains the
purification mechanism. Crystals of the TlF product
are cubic, space group Pn3m, with a 11.277(1) Ǻ. The absorption corrected
data gave a conventional R value of 0.043 on full- matrix least-squares
refinement. This product is predominantly the monofluoride species but the
other differently substituted ones form isomorphous crystals. The molecules are
cubane-type clusters of Mn(CO)3 groups at
one set of corners interpenetrated with fluoro or
hydroxy groups at the other set and exhibit crystallographic symmetry 43m.
These interpenetrating tetrahedra have edge length of 3.199(1) and 2.529(3)
Ǻ respectively consistent with values expected for limiting non-bonding
contacts.
Vibrational spectra of adducts of iodine monochloride with some pyridine bases
Authors: Bowmaker GA , Tan K , Taylor MJ
Published: September 2010

A series of molecular
adducts, L-ICl, where L = pyridine or a pyridine
derivative, have been prepared and the solid state spectra examined by Raman
and far-infrared spectroscopy. Assignments of the modes v(I-Cl)
240-300 cm-1 and v(N-I) 90-180 cm-1 and force constant
calculations on a simple three-centre model yield information on structure and
bonding related to the nature of the pyridine donor. Several ionic products
containing the Icl2- ion have been encountered.