bluuebunny/crossref_metadata_2025 huggingface dataset:
Complex formation of beryllium sulfate in mixtures of water and dimethylformamide
Authors: Gislason BI , Strehlow H
Published: September 2010

The complex formation of BeSO4 in mixtures of water and dimethylformamide (dmf) has been studied
by using conductivity and kinetic measurements. In these solutions the complex Be(SO4)22- is
shown to exist together with the outer- and inner-sphere complex of BeSO4. The rate of substitution
depends on the composition of the solvatomer Be(H20)I(dmf)4-I2+ which reacts with the sulfate
ion and on the kind of solvating molecule which is substituted by the ligand SO42-.
Structural studies in the iron(III)/chloride/α,α'-diimine system. I. The six-coordinate mononuclear fac-[FeCl3(phen)X] system, X = MeOH, H2O, Cl-
Authors: Healy PC , Patrick JM , Skelton BW , White AH
Published: September 2010

The crystal structures of three iron complexes [FeCI3(phen)(MeOH)].MeOH (I), [FeCl3(phen)(H2O)]
(2) and [phenH]+ [FeCl4(phen)]- (3) have been determined by single-crystal X-ray diffraction methods
at 295(1) K, and refined by least squares to residuals of 0.044 (1600 'observed' reflections), 0.040
(806) and 0.050 (2496), respectively. Crystals of (1) are monoclinic, P21/c, a 8.005(9), b 14.805(11),
c 14.830(12) A, P 101.03(7)°, Z 4; for (2), triclinic, space group P1 , a 10.591(8), b 10.227(7),
c 6.613(3) Ǻ, α 108.21(5), β 100.69(5), γ 91.98(6)°2, 2 ; for (3), triclinic, P1, a 18.560(8), b 10.302(5),
c 6.981(3) Ǻ, α 106.79(4), β 94.50(4), γ 103.15(4)°, Z 2. In all structures, the iron atoms are six-coordinate,
with the disposition of the three chlorine atoms being fac in (1) and (2).
Structural studies in the iron(III)/chloride/α,α'-diimine system. II. Ionic derivatives of stoichiometry FeCl3(phen,bpy)1,1.5
Authors: Figgis BN , Patrick JM , Reynolds PA , Skelton BW , White AH , Healy PC
Published: September 2010

The crystal structures of the 1 : 1 adducts of FeCl3 with 2,2'-bipyridine (bpy) (1) and 1,10-phenanthroline
(phen) (2), as recrystallized from nitromethane, have been determined by single-crystal
X-ray diffraction methods at 295 K, being refined by least squares to residuals of 0.038 and 0.032
for 1341 and 3968 'observed' reflections; the result for (2) is a redetermination. Crystals of (1)
are orthorhombic, Pbnb, a 15.013(4), b 13.510(5), c 12.471(3) Ǻ, Z 4. Crystals of (2) are triclinic,
P1, a 15.823(5), b 11.021(5), c 8.200(3) Ǻ, α 80.27(3), β 76.78(3), γ 89.64(3)°, Z 2. Both complexes
haw the stoichiometry (FeCl3)1(bpy,phen)1, but are formulated as cis-[Fe(bpy,phen)2Cl2] [FeCl4];
in both compounds, the Fe-N distance is c. 2.20, (trans to Cl), 2.1, Ǻ(cis to Cl), while Fe-Cl,
c. 2.2, Ǻ, is short. The structure determinations of Fe2Cl6(phen,bpy)3 as [Fe(phen)2Cl2]+
[Fe(phen)Cl4]- (3) and [Fe(bpy)2Cl2]+ [Fe(bpy)Cl4]- (4) are also reported. Compound (3) (from
acetonitrile solution) is triclinic, P1, a 16.502(5), b 11.857(3), c 10.653(3) Ǻ, α 84.92(2), β 72.66(2),
γ 74.80(2)°, Z 2, and was refined to a residual of 0.034 for 5540 'observed' reflections. The cation
geometry is similar to that of (2); in the anion, the two Fe-CI bonds trans to each other are
long [2.377(1) and 2.365(1) Ǻ] while those trans to the Fe-N bonds are short [2.287(1) and
2.318(1) Ǻ]. Fe-N distances are 2.216(3) and 2.220(3) A. Compound (4) (as its nitromethane
solvate) is also triclinic, P1, a 14.480(7), b 12.645(5), c 10.678(4) Ǻ, α 95.68(3), β 109.21(3),
γ 9258(3)°, Z 2; a residual of 0.042 was obtained for 4962 'observed' reflections. Cation and
anion metal geometries are similar to those of (3).
Light-induced electron-transfer reactions involving the Tris(2,2'-bipyridine)ruthenium dication and related complexes. II. Effect of the 2-(Thiazol-2'-yl)pyridine ligand
Authors: Fitzpatrick LJ , Goodwin HA , Launikonis A , Mau AWH , Sasse WHF
Published: September 2010

The complexes [Ru(bpy)n(thpy)3-n
]2+ [where bpy = 2,2'-bipyridine, thpy
= 2-(thiazol-2'-yl)pyridine, and n = 2, 1 or 0] sensitize the photo reduction
of water and inhibit the hydrogenation of methylviologen.
Compared with Ru(bpy)32+, the
turnover numbers of methylviologen are increased but
the rates of formation and yields of hydrogen are lowered. Photophysical
and kinetic data have been used to explain the observed effects.
Reactions of methyl radicals. IV. Hydrogen abstraction from tetramethylsilane by methyl radicals produced by the photolysis of both acetone and azomethane
Authors: Arican H , Arthur NL
Published: September 2010

Studies of hydrogen abstraction by CH3 radicals from (CH3),Si with two different radical sources,
acetone and azomethane, have yielded data on the reactions
CH3 + Ch3COCH3 → CH4 + CH3COCH2 (1)
CH3 + CH3NNCH3
→ CH4 + CH3 NNCH2 (2)
Ch3 + (Ch3)4Si → Ch4 + (CH3)3SiCH2
Their rate constants, based on the value of 1013.34 cm3 mol-1 s-1 for the recombination of CH3
radicals, together with the corresponding experimental temperature ranges, are given by (k in
cm3 mol-1 s-1, E in J mol-1):
log k2 = (11.54±0.02) - (40 000±220)/19.145T 398-522 K (2)
log k8 = (10.98±0.02) - (32 550±160)/19.145T 334-463 K (8)
log k8' = (11.03±0.02) - (32 920±180)/19.145T (8')
With acetone as the radical source:
log k5 = (11.85±0.06) - (44 810±160)/19.145T 395-523 K (5)
With azomethane as the radical source:
log ks = (11.88±0.03) - (44 610±260)/19.145T 363-463 K (5)
log k5' = (12.02±0.04) - (45 630±310)/19.145T (5')
where k5' and k5' are the values for ks and k5, respectively, obtained after allowance is made for the
formation of C2H6 by way of the intramolecular decomposition of azomethane. From a consideration
of these and previously reported data on CH3 and CD3 attack on (CH3)4Si, we conclude that the
source of CH3 radicals, and the intramolecular formation of C2H6 in the photolysis of azomethane,
both have a negligible effect on the rate constants for the reaction, and that CH3 and CD3 radicals
are of equal reactivity. We also recommend best values for the Arrhenius parameters for the reaction.
Heterocyclic analogues of phthalhydrazides: Cyclic hydrazides of pyridine 1-oxide and pyrazine 1,4-dioxide dicarboxylic acids
Authors: Paul DB
Published: September 2010

The synthesis of N-oxides of the cyclic hydrazides of
pyridine and pyrazine o-dicarboxylic
acids is described. Pyrido[2,3-d]pyridazine-5,8-dione 1-oxide, pyrido[3,4-d]pyridazine-1,4-dione
6-oxide, and pyrazino[2,3-d]pyridazine-5,8-dione 1,2-dioxide, were obtained by
direct oxidation of the parent hydrazides with peracetic acid. The
pyridopyridazine derivatives were also unambiguously synthesized by treating
the anhydrides or diesters of the relevant carboxylic acid 1-oxides with
hydrazine hydrate.
Heterocyclic amplifiers of phleomycin. I. Some pyrimidinylpurines, pyrimidinylpteridines and phenylpyrimidines
Authors: Brown DJ , Cowden WB , Lan S , Mori K
Published: September 2010

Synthetic routes are
described to 5,6-diamino-2,4'-bipyrimidin-4-ones and thence to
2-(pyrimidin-4'-yl)purines and 2-(pyrimidin-4'-yl)pteridines, some of which bear a sulfur- or nitrogen-linked
basic side chain; also reported are routes to a series of phenyl- and diphenyl-pyrimidines, to each of which is attached a similar
sulfur-, nitrogen-, or oxygen-linked side chain. Members of all the above
systems show activity as amplifiers of phleomycin in
a bacterial screen but the phenylpyrimidines with a
sulfur-linked side chain are especially active.
Preparation of Nα-(t-Butoxycarbonyl)-O-(dibenzylphosphono)-L-serine
Authors: Alewood PF , Perich JW , Johns RB
Published: September 2010

The protected phosphoserine synthon Nα-(t-butoxycarbonyl)-O-(dibenzylphosphono)-L-serine
was prepared in three steps. Stability studies on the phosphorylating
agent dibenzyl phosphorochloridate
were performed by 31P n.m.r. spectroscopy.
The photochemistry of alkyl 2-(Naphthalenyl)ethenylbenzoates: Photodehydrocyclization and photodimerization products and their structural elucidation by 1H and 13C N.M.R.
Authors: Jones AJ , Teitei T
Published: September 2010

Irradiation of alkyl
2-[2-(naphthalen-1-yl)ethenyl]benzoates in benzene
gave the photodehydro-cyclization product, the chrysenecarboxylates (3) as well as two of the photodimerization products, the cyclobutanes
(6) and (7). Similarly, irradiation of alkyl 2-[2-(naphthalen-2-yl)ethenyl]benzoates furnished the benzo[c]phenanthrenecarboxylates (4) and the cyclobutanes
(8) and (9). Photodehydro-cyclization appears to be
favoured over the photodimerization in more polar
media. Complete analyses of 1H and 13C n.m.r. spectra of
some of these compounds are presented along with the spectra of the parent
chrysene for comparison. The structures and the stereochemistries
of all the products obtained were determined principally from these n.m.r.
analyses.
Synthetic approaches to phthalazines: C-N bond cleavage in 2'-benzylbenzohydrazides during reaction with polyphosphoric acid
Authors: Paul DB
Published: September 2010

Reaction of
2'-benzylbenzohydrazides with concentrated polyphosphoric
acid gave 2,5-diaryl-1,3,4- oxadiazoles and a polybenzyl. Cyclodehydration to phthalazines was not observed. It is inferred from product
substitution patterns that CH2-N bond cleavage occurs with polybenzyls forming from the benzyl moiety and oxadiazoles from the benzohydrazide
fragment. Other reported reactions which generate benzyl fragments lead to bibenzyl and are considered to involve trapping of the
cleavage products within a solvent cage. The observed production of polybenzyls is therefore interpreted in terms of the
formation of free benzyl fragments. A tetrahydrophthalazine
derivative was produced from the addition of diethyl azodicarboxylate
to the photodiene of o-methylbenzophenone, but this could not
be converted into a phthalazine.
Meisenheimer complex formation between 4,6-dinitrobenzofurazan 1-oxide and primary, secondary and tertiary aromatic amines
Authors: Read RW , Spear RJ , Norris WP
Published: September 2010

The uncatalysed formation
of stable 1 : 1 Meisenheimer complexes between primary, secondary and tertiary
aromatic amines and 4,6-dinitrobenzofurazan 1-oxide has been investigated. The
thermodynamic product is derived from reaction through the aromatic carbon para
or, if this position is substituted, ortho to the amino group of the aromatic
amine. The complexes are stable to acid but react in aqueous potassium hydrogen
carbonate solution or with aliphatic or aromatic amines to give crystalline
salts of the complexes. In the presence of 1,4-diazabicyclo[2.2.2]octane,
aniline reacts with 4,6-dinitrobenzofurazan 1-oxide to give an unstable
nitrogen-bonded complex which is slowly converted into the carbon-bonded
complex. The scope of the complexation reaction has been investigated and some
of the mechanistic implications of the results are discussed.
The constituents of marine sponges. I. The isolation from Aplysilla sulphurea (Dendroceratida) of (1R*, 1'S*, 1'R*,3R*)-1-Acetoxy-4-ethyl-5-(1,3,3-trimethylcyclohexyl)-1,3-dihydroisobenzofuran-1'(4),3-carbolactone and the determination of its crystal structure
Authors: Karuso P , Skelton BW , Taylor WC , White AH
Published: September 2010

Extraction of the sponge Aplysilla sulphurea
(Order, Dendroceratida) yielded two crystalline substances,
aplysulphurin, C22H28O5,
and aplysulphuride, C22H32O5
Chemical and spectroscopic evidence suggested that aplysulphurin,
the title compound, had the structure (2). This was confirmed by a
single-crystal X-ray determination.
The isomeric 1,3,3-Trimethyl-2-oxabicyclo[2.2.2]octan-6-ol (2-Hydroxy-1,8-cineoles)
Authors: Carman RM , Fletcher MT
Published: September 2010

The stereochemistry of the
title compounds, and of the two 1,2-epoxy-p-menthan-8-ols, is discussed.
The photochemistry of aliphatic and alicyclic α,β-unsaturated nitro compounds. A study of double bond cleavage following intramolecular cyclization and nitro-nitrite rearrangement
Authors: Grant RD , Pinhey JT
Published: September 2010

The light-induced
intramolecular cyclization of α, β-unsaturated nitro compounds
leading to double bond cleavage, which had previously been detected in a small
number of β-nitrostyrenes and α-nitro-stilbenes, has been shown to occur in a range of aliphatic
and alicyclic α, β -unsaturated nitro compounds. At room temperature
the reaction competes to a significant extent with the well known nitro-nitrite
rearrangement in the irradiation of 1-nitro-2-phenylcyclohexene (2),
1-methyl-2-nitro-cyclohexene (6), 1-methyl-2-nitrocycloheptene
(11), 2-methyl-3-nitrobut-2-ene (23) and 2-nitro-3-phenylbut-2-ene (24), while
it was the only reaction detected in the case of 1-methyl-2-nitrocyclo- octene (12) and 1-nitrocyclooctene (19). No evidence for
the cleavage reaction was found with 1-methyl-2-nitrocyclopentene (10),
1-nitrocyclohexene (17), 1-nitrocycloheptene (18) and 3-nitropent-2-ene (25).
The nitrile oxides produced in the double bond
cleavage reaction were trapped in a cycloaddition with methyl acrylate, yielding
3-substituted methyl 4,5-dihydroisoxazole-5-carboxylates. Irradiations of
1-methyl-2-nitrocyclohexene (6) and 1-methyl-2-nitrocycloheptene (11) in
refluxing benzene afforded only the bridged ring isoxazolines
(30) and (31) respectively. Syntheses of a number of nitro-olefins are also
reported.
Stannylation and germylation of some 4-, 5- and 6-Alkylcyclohex-2-enyl chlorides
Authors: Young D , Kitching W , Wickham G
Published: September 2010

The allylic alcohols, trans-5-t-butylcyclohex-2-enol, trans-4-t-butylcyclohex-2-enol and trans-4- methylcyclohex-2-enol, have
been converted into cyclohex-2-enyl chlorides by reaction with thionyl chloride
and N-chlorosuccinimide-dimethyl sulfide. The stereochemistry of the allylic
chlorides has been determined by 1H and 13C nuclear
magnetic resonance spectroscopy. Stannylation of these chlorides with
trimethyltinlithium, and triphenyltinlithium, has been examined and the
resulting stannanes fully characterized by 1H, 13C and 119Sn
n.m.r, spectroscopy, and electrophilic cleavage (acidolysis with deuterated
trifluoroacetic acid) to the corresponding deuterocyclohexenes. A less
extensive study of germylation (trimethylgermyllithium in
hexamethylphosphoramide) was conducted also, and the allylic germanes fully
characterized. Triphenyltinlithium and trimethylgermyllithium exhibit higher
levels of stereo- and regio-specificity in chloride displacement than
trimethyltinlithium.
Oxygen-functionalization of 9-hydroxyphenalenone
Authors: Haddon RC
Published: September 2010

The present paper reports
the synthesis of the acetate of 9-hydroxyphenalenone and related compounds and
some of their properties. The crystal structure of 9-butoxyphenalenone has been
determined and its geometry is compared with that of 9-hydroxyphenalenone.
A synthesis of 2,4-dihydroxyisoflavans and 2-Hydroxyisoflav-3-enes: Versatile precursors to isoflavanoids
Authors: Liepa AJ
Published: September 2010

A new synthesis of isoflavanoids has been developed by treatment of a
salicylaldehyde with an arylglycidate salt. Reaction
conditions have been found so that this condensation yields either a
2,4-dihydroxyisoflavan or a 2-hydroxyisoflav-3-ene. A 2-hydroxyisoflav-3-ene
such as (8a) can then be converted into the isoflavylium
salt (9b), isoflavan (11b),
2-hydroxyisoflavan (11a), isoflav-2-ene (13) or isoflav-3-ene (10d). Similarly,
the 2-aminoisoflav-3-ene derivative (10f) can be obtained from (8d). The reaction
of isoflavylium salts or (8a) with
3-mercaptopropionic acid gives isoflav-3-ene derivatives (15) potentially
useful as haptens for conjugation with suitable
macromolecules for the generation of antibodies.
The Addition of t-Butoxy Radicals to Halo-olefins
Authors: Cuthbertson MJ , Rizzardo SDH
Published: September 2010

A radical trapping technique employing 1,1,3,3-tetramethylisoindolin-2- yloxyl (1) as scavenger has been used to examine the regioselectivity for tail or head addition (kT/kH) by t-butoxy radicals to chloroethylene (5), fluoroethylene (6), 1,1-difluoroethylene (7) and 1,1,2- trifluoroethylene (8) at 30-75°C. Addition rates relative to
that for ethylene (4) have also been evaluated. An atypical preference for head addition was observed for olefins (7) and (8). In the case of (7) the regioselectivity was shown to vary with temperature according to ���������������������� In(kT/kH) = (1.06�0.01)-(800�40)/TA comparison of the selectivity with that of other radicals indicates that t-butoxyl exhibits nucleophilic character in its addition to halo-olefins.
Heterocyclic Tautomerism. II. 4-Acylpyrazolones. X-Ray Crystal Structures of 4-Benzoyl-5-methyl-2-phenylpyrazol-3(2H)-one and 4-Acetoacetyl-3-methyl-1-phenylpyrazol-5-ol
Authors: O'Connell MJ , Ramsay CG , Steel PJ
Published: September 2010

The colourless crystalline form of the benzoylpyrazolone (2) has molecules with the NH structure (2c) stabilized by intermolecular hydrogen bonds. At room temperature crystals are monoclinic: P21/c, a 13.508(5),
b 9.124(4), c 11.451(3)Ǻ, β 90.80(3)°, Z4; the structure was refined to R 0.059, Rw 0.048. The acetoacetylpyrazolone (3) has the OH structure (3c) with two intramolecular hydrogen bonds. At 193 K crystals are triclinic: Pī , a 7.142(2), b 13.704(8), c 14.699(7)Ǻ, α 117.36(3), β 96.87(3),
γ 93.73(3)°, Z 4; the structure was refined to R 0.049, Rw 0.054.
Some Rearrangements of 2,4,6-Tri-t-butyl-4-nitrocyclohexa-2,5-dienone
Authors: Hartshorn MP , Kennedy JA , Simpson RW , Vaughan J , Wright GJ
Published: September 2010

Rearrangement of 2,4,6-tri-t-butyl-4-nitrocyclohexa-2,5-den (20) in benzene gives the 4-hydroxy dienone (21) and the mono-de-t- butylated 1,2-benzoquinone (22). The rearrangement is not affected by the addition of mesitylene , but the phenol-coupling product (26) is formed in the presence of p-cresol, and the nitromethyl phenol (31) is formed when the nitro dienone (20) rearranges in the presence of 2,4,6- trimethylphenol (29). The rearrangements of the nitro dienone (20) in methanol are described.
Micellar Catalysis of Organic Reactions. XVII. Hydrolysis of Nitrazepam and Some N-Alkylated Derivatives
Authors: Broxton TJ , Morrison SR
Published: September 2010

Product studies for the acid catalysed hydrolysis of nitrazepam and some N-alkyl derivatives in the presence of micelles of sodium dodecyl sulfate ( sds ) have been carried out by a U.V. spectrophotometric technique. Attack of water at C2 leading to initial amide cleavage is favoured by high acid concentrations, by micelles of sds and by small R groups attached to the amide nitrogen atom. For nitrazepam, a change of mechanism from water attack at C5 (leading to initial azomethine cleavage) to water attack at C2 (leading to initial amide cleavage) was observed on transfer from water to micelles of sds . For N-benzyl nitrazepam (1d), however, no change of mechanism was detected. Initial attack of water occurred at C5 (leading to initial azomethine cleavage), both in aqueous solution and in micelles of sds.
Photosolvolysis of Bridgehead Quaternary Ammonium Salts. III. Synthesis of Some 3-Benzazecine, 1H-2,6-Benzoxazecine and 2H-3,6-Benzoxazecine Derivatives and a 2H-1,4-Oxazocine Derivative
Authors: Bremner JB , Winzenberg KN
Published: September 2010

Photosolvolysis of a mixture of cis - and trans-9,10-dimethoxy-5-methyl- 1,3,4,6,7,11b-hexahydro-2H-benzo[a] quinolizinium iodide (2) in methanol gave, after workup, a very low yield of 8,10,11-trimethoxy-3-methyl- 1,2,3,4,5,6,7,8-octahydro-3-benzazecine (3a). Similarly 1,10,11 trimethoxy-6-methyl-3,4,5,6,7,8-hexahydro-1H-2,6-benzoxazecine (8a) and 1,10,11-trimethoxy-6-methyl-1,4,5,6,7,8-hexahydro-2H-3,6-benzoxazecine (16a) were obtained in fair and low yields respectively from the N- methyl tetrahydro-2H,6H-[1,3] oxazino [2,3-a] isoquinolinium (7a) and hexahydro [1,4] oxazino [3,4-a] isoquinolinium (15) iodide precursors; a 1- methyl derivative (8b) of (8a) was also prepared. The ring-opened products 3-[N-2-{(4,5-dimethoxy-2-dimethoxymethyl)-phenyl}ethyl-N-methyl]aminopropan-1-ol (9a) and 3-[N-2-{(4,5-dimethoxy-2-1′,1′- dimethoxyethyl )-phenyl}ethyl-N-methyl]aminopropan-1-ol (9b) were also obtained from the [1,3] oxazino [2,3-a]- isoquinolinium salt derivatives. Photolysis of (2) and 9,10-dimethoxy-5-methyl-1,3,4,6,7,11b-hexa-hydro[1,4] oxazino [3,4-a] isoquinolinium iodide (15) in acidified aqueous solution afforded, after workup, the benzazecin-8-ol (3b) and hexahydro-2H-3,6-benzoxazecin-1-ol (16b) products respectively, but again in very low yield. Some mechanistic rationalizations of
these results are given.Photosolvolysis of 7a-(3,4-dimethoxy)phenyl-4-methyl-2,3,5,6,7,7a- hexahydropyrrolo [2,1-b] oxa-zolium iodide (22) in methanol afforded a high yield of 8-methoxy-4-methyl-8-(3,4-dimethoxy)-phenyl-3,4,5,6,7,8- hexahydro-2H-1,4-oxazocine (24) in a new ring-destruction approach to this ring system. From 13C n.m.r . data, the twist-boat-chair conformation was tentatively assigned to (24) in (D)chloroform solution.
Heterocyclic Amplifiers of Phleomycin. IX. Some Derivatives of Fused and Unfused Mono- and Di-aza Heterocycles
Authors: Barlin GB , Ireland SJ
Published: September 2010

Some mono- and bis-dimethylaminoethylthio, dimethylaminopropylthio and carbamoylmethylthio derivatives of pyridine, pyridazine , 1,3,4- thiadiazole , thiazoline , quinoline , quinoxaline , quinazoline , phthalazine , 6-nitrobenzothiazole and benzimidazo [1,2-c] quinazoline have been prepared for testing as amplifiers of phleomycin. These compounds showed relatively low activity; the highest activity was shown by 4-(2′-dimethylaminoethylthio) quinoline at three star, but a number were antibacterial under the test conditions.
Alkylation of 4-Nitroimidazole-5-Thiol With Alpha,Omega-Dihalides to Form Bicyclic Derivatives
Authors: Grimmett MR , Vanhorik ET , Kulkarni SR
Published: September 2010

The ammonium salt of 4-nitroimidazole-5-thiol is alkylated at N and S by 1,2-dichloroethane, 1,3-dibromopropane, and 1,4-dibromobutane to give bicyclic products. These cyclic thioethers can be oxidized to the sulfones , and brominated in the imidazole ring, while the bromine atom is subject to nucleophilic displacement by piperidine.
The Structures of the Free-Radical Scavenger 1,1,3,3-Tetramethylisoindolin-2-Yloxyl, and of the Alkoxy Amine Derivative 5-(1,1,3,3-Tetramethylisoindolin-2-Yloxy)-1-Vinylpyrrolidin-2-One
Authors: Busfield WK , Engelhardt LM , Healy PC , Jenkins ID , Thang SH , White AH
Published: September 2010

The structures of the title nitroxide , C12H16NO (1), and the alkoxy amine derivative, C18H24N2O2 (2), have been determined by single-crystal X-ray structural analyses. Crystals of (1) are monoclinic, space group Cc with a 11.585(6), b 11.697(10), c 16.753(8)Ǻ, β 94.33(6)°, Z 8; R was 0.064 for 1226 independent reflections. The -C(NO)C- group is essentially planar (sum trigonal angles 359.9, 359.9°, as is the five- membered ring. The N-O distances are 1.249(6), 1.252(8)Ǻ. Crystals of (2) are monoclinic, space group P21/c, a 8.295(2), b 13.567(5), c 15.294(3)Ǻ, β 98.82(2)°, Z 4; R was 0.051 for 1445 independent reflections. By contrast to (1) the geometry about the nitrogen atom is pyramidal (sum trigonal angles 328°), and the corresponding five-membered ring has an envelope conformation with a nitrogen displacement of 0.45Ǻ. The N-O distance is 1.439(4)Ǻ. The high-resolution solid state 13C n.m.r . spectrum of (2) is discussed in relation to the X-ray structure.
The Synthesis of (3'-Oxo-3',4'-Dihydro-2'h-1',4'-Benzothiazin-2'-Yl)Acetic Acid and (3'-Oxo-3',4'-Dihydro-2'h-1',4'-Benzoxazin-2'-Yl)Acetic Acid-Derivatives
Authors: Teitei T
Published: September 2010

Reaction of o-aminophenol with various maleic anhydrides gave first 2-hydroxymaleanilic acids (4-(2′-hydroxyphenylamino)-4-oxobut-2-enoic acids) (1), which were then converted into the 3-oxo-1,4-benzoxazines (2d-h) and (3f-1) under mild basic conditions; similarly the reaction of o- aminothiophenol with the maleic anhydrides gave the 3-oxo-1,4-benzothiazines (2a), (3a) and (3d) in one step. The facile cycloaddition and esterification of 2-hydroxymaleanilic acids to form the benzoxazines observed in this work is discussed in terms of the formation of the isomaleimide type intermediate (7).
1-Benzazepines. The Synthesis and Reactivity of 2-Chloro-1,5-Dimethyl-1h-1-Benzazepines
Authors: Bowie JH , Hayes RN , Mitkas S , Prager RH , Raftery MJ , Skelton BW , Stringer MB , White AH
Published: September 2010

Treatment of laevulinic acid with N- methylaniline yields 1,5-dimethyl- 1H-1-benzazepin-2(3H)-one and 5-methyl-5-[4-( methylamino )phenyl]-1- phenylpyrrolidin-2-one. The
structure of the latter is confirmed by a single-crystal X-ray study. The yield of benzazepinone is increased if either m- methoxy-N-methylaniline or m-methyl-N- methylaniline is allowed to react with laevulinic acid. Treatment of the benzazepinones with phosphoryl chloride in pyridine produces 2-chloro-1,5-dimethyl-1H-1- benzazepines in quantitative yields, but these compounds are highly reactive under acidic conditions, undergoing nucleophilic displacement at C2. In contrast, treatment of benzazepinones with neat phosphoryl chloride yields yellow dimers , assigned as 2′-chloro-1,1′,5,5′- tetramethyl-2,3′-bi-1H-1-benzazepines, and with stabilities only marginally greater than those of the 2-chloro-1,5-dimethyl-1H-1- benzazepines.
The Crystal-Structure of Bis(O-Ethylxanthato)-Triphenylphosphinenickel(II) - Ni(S2COC2H5)2P(C6H5)3
Authors: Tiekink ERT , Winter G
Published: September 2010

The crystal and molecular structure of the 1:1 adduct formed between bis (O- ethylxanthato )nickel(II) and triphenylphosphine is reported. The nickel atom is five-coordinate in a distorted square-pyramidal geometry with a sulfur atom, from an asymmetrically coordinating xanthate ligand , in the apical position. Crystals are triclinic, space group Pī, a 10.265(4), b 14.718(5), c 8.818(4) Ǻ, α 100.77(3), β 92.16(4),
γ 89.56(3)° with Z 2. The structure was refined by a least-squares method; R 0.068 for 3301 reflections with I ≥ 3.0σ(I).
A Ring Destruction Approach to Some Benzo-Fused Medium-Sized Heterocycles by Means of Cyanogen-Bromide Under Solvolytic Conditions - X-Ray Structure of a '1h-2,6-Benzoxazecine-6-Carbonitrile and a '2h-3,6-Benzoxazecine-6-Carbonitrile Derivative
Authors: Bremner JB , Raston CL , Rowbottom GL , White AH , Winzenberg KN
Published: September 2010

Reaction of the reduced pyrrolo [2,1-a] isoquinoline amine (1a) with cyanogen bromide in the presence of
methanol gave the medium-ring cyanamide derivative 7,9,10-trimethoxy-2,3,4,5,6,7-hexahydro-1H-3- benzazonine-3-carbonitrile (2a). Analogous products were also obtained from reaction of the reduced
5H-oxazolo[2,3-a] isoquinoline , 2H- benzo [a] quinolizine , 2H,6H-[1,3] oxazino [2,3-a] isoquinoline and [1,4] oxazino [3,4-a] isoquinoline derivatives (1b-e), whereas the reduced 3H-oxazolo[4,3-a] isoquinoline and 5H-oxazolo[2,3-a] isoquinoline derivatives (1f) and (8) gave 1-(2,4-dioxapentyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-2-carbonitrile (5a) and N-[2-(2-benzoyl-4,5-dimethoxyphenyl)ethyl]-N- methylcyanamide (9) respectively, the latter in low yield. The medium-sized heterocyclic derivatives (2f-h) were also obtained from cyanogen -bromide-mediated water solvolysis reactions of (1a), (1c) and (1e). The cyanamides (2a-h), (5a) and (9) have been converted into the respective tertiary amine derivatives (3a- h), (5c) and (11), with concomitant reduction of the carbonyl group in the last case. The crystal and molecular structure of 1,10,11- trimethoxy-3,4,5,6,7,8-hexahydro-1H-2,6-benzoxazecine-6-carbonitrile (2d) and 1-hydroxy-10,11-dimethoxy-1,4,5,6,7,8-hexahydro-2H-3,6- benzoxazecine-6-carbonitrile (2h) have been determined by single- crystal X-ray methods.
Relative Reactivities of Various Sulfides, Selenides and Halides Towards SH2 Attack by Tributylgermyl Radicals
Authors: Beckwith ALJ , Pigou PE
Published: September 2010

The order of reactivity towards SH2 attack by tributylgermyl radicals on various groups X in four different molecular environments (RCO2CH2X, RCH2OCH2X, XCH2CO2Et and RCH2X) has been found by competition experiments to be Br > PhSe > Cl > p-NCC6H4S > PhS . The relative rates of addition of Bu3Ge? To three classes of olefins have also been determined.
The Photolysis of Aqueous-Solutions of Potassium Hexacyanoferrate(III)
Authors: Fuller MW , Lebrocq KMF , Leslie E , Wilson IR
Published: September 2010

The photolysis of aqueous solutions of potassium hexacyanoferrate(III) at 254 and 366 nm forms aqua- or hydroxo-pentacyanoferrate(III) in both acidic and alkaline solutions, with quantum yields between 0.02 and 0.06. Subsequent thermal reactions form the decacyanodiferrate(III) and/or decacyanodiferrate(III,II) species, especially in weakly acidic solutions, and, in alkaline solutions, may precipitate hydrated iron(III) oxides.
A Polymeric Silver Lutidine Tetrafluoroborate Compound, [Ag( lut )2(µ4-BF4)]N, With Weak μ4-Tetrafluoroborate Coordination to Silver
Authors: Horn E , Snow MR , Tiekink ERT
Published: September 2010

Silver tetrafluoroborate reacts with 2,6-lutidine ( lut ), in dichloromethane solution, to form the polymeric compound [Ag( lut )2(�4-BF4)]n. The polymeric structure is comprised of [Ag( lut )2]+ units each of which is connected by two bidentate links to two [�4-BF4]-anions. The compound crystallizes in the tetragonal space group I41/acd with a 15 .O69(4) and c l4.391(3) �. A full-matrix least-squares refinement on 271 reflections, with I ≥ 2.5σ(I), converged with final R 0.027 and Rw 0.025. The complex exhibits an unusual splitting of the BF4 v3 mode into six peaks which has been interpreted as three doublets arising from coupling between the BF4- anions attached to the same silver atom.
The Preparation of 9-Oxo-10-Oxaprostanoids by the Conjugate Addition of (E)-1-(Phenylthio)Oct-2-Enyllithium to γ-Crotonolactone and the Direct Alkylation of the Derived Enolate With Methyl 7-Bromohept-5-ynoate and Related Electrophiles
Authors: Haynes RK , Schober PA
Published: September 2010

The conjugate addition of (E)-1-(pheny1thio)oct-2-enyllithium in tetrahydrofuran containing hexamethylphosphoric triamide to γ-crotonolactone (but-2-en-4-olide) followed by treatment of the resulting lactone enolate with either methyl 7-bromohept-5-ynoate or 7-bromohept-5-ynenitrile gave the corresponding enolate trapped products in yields of 50-55% from the octenyllithium reagent. Use of 7-iodohept-5-ynoate gave a slightly higher yield than the first electrophile. Treatment of the enolate with triphenyltin chloride prior to addition of the electrophiles resulted in approximately 5-10% enhancement of the yields of the products. The products obtained from the methyl 7-halohept-5-ynoates were converted into the 9-oxo-l0-oxaprostanoids through the corresponding sulfoxides and the allylically transposed alcohols by a standard sequence of reactions. In an attempt to convert the lactone ring of the enolate-trapped products into the fully carbocyclic nucleus of primary prostaglandins, the nucleophilic ring opening of the lactone nucleus with the lithiated carbanion derived from t-butyl methyl sulfone in the presence of N, N, N', N'- tetramethylethylenediamine was carried out. However, attempts to oxidize the resulting hemiacetals to the requisite diketone precursors of the carbocyclic prostaglandins were unsuccessful.
Synthesis of 4-(4'-Chlorophenyl)-5-Phenyl-1,2-Dihydronaphthalene
Authors: Cosmo R , Sternhell S
Published: September 2010

BF3-catalysed cyclization reactions of 1-(biphenyl-2'-y1)- 1-(4″-chlorophenyl)but-3-en-1-ol yielded none of the desired title compound but only 9-(4'-chloropheny1)-10-ethylphenanthrene and 9-allyl-9-(4'-chlorophenyl) fluorene by alternative cyclization pathways. Corresponding cyclization of the related diene 1-(biphenyl-2'-yl)-1-(4″-chlorophenyl)buta-1,3-diene also failed to yield the desired title compound but gave instead the unexpected product 9-(4'-chlorophenyl) phenanthrene through a novel mechanism. Flash pyrolysis of l-(biphenyl-2'-yl)-l-(4″-chlorophenyl)buta-1,3-diene gave the desired compound as a minor constituent of the reaction mixture, the major constituent being 4-(biphenyl-2'-yl)-7-chloro- 1,2-dihydronaphthalene.
Preparation of Some 2-(Methoxyphenyl)-2H-benzotriazoles and the Corresponding Hydroxyphenyl Compounds
Authors: Rosevear J , Wilshire JFK
Published: September 2010

The reaction of several substituted o- nitronitrosobenzenes with O- and p- anisidine , and 2,4- dimethoxyaniline in acetic acid gives in good yield the corresponding enitroazobenzenes which are readily reduced with thiourea dioxide ( formamidinesulfinic acid) to the corresponding 2-(methoxypheny1)-2H-benzotriazoles, demethylation of which furnished the corresponding 2- (hydroxypheny1)-2H-benzotriazoles. Demethylation of the dimethoxy derivatives was best accomplished with boron tribromide in methylene chloride, the methoxy group located ortho to the benzotriazole ring being demethylated more readily than is the para-methoxy group. The reaction of enitroazobenzenes containing a methoxy group with hydrobromic acid in acetic acid results in cleavage of the azo bond and also partial bromination to give o- nitroaniline and some of its brominated derivatives.
The Chemistry of Ethyl 2-Ethoxycarbonyl-5,5-Diphenylpenta-2,3,4-Trienoate, a Potential Precursor of Ph2c=C=C=C=C=O
Authors: Browne NR , Brown RFC , Eastwood FW , Fallon GD
Published: September 2010

The title diester , Ph2C=C=C=C( COOEt )2 (2), has been prepared by a Wittig reaction between (2-bromo-3,3-diphenylprop-2-en-1-yl) triphenylphosphonium bromide and diethyl 2-oxopropane-1,3-dioate ( mesoxalic ester). The diester (2) undergoes cyclization reactions in concentrated sulfuric acid to give diethyl 2-(3'-phenyl-1H-inden-1'-y1idene)propane-l,3-dioate (4) and triethyl 3-oxo-3',9-diphenyl-2,3-dihydrospiro[lH-fluorene-1,l'-[1H]indene]-2,2,4-tricarboxylate (6), the structure of which was determined by X-ray crystallography. The title diester (2)adds cyclopentadiene across the 2,3-C=C bond to give diethyl 3-(2',2'-diphenylethenylidene)bicyclo[2.2.l]hept-5-ene-2,2-dicarboxylate (10). Alkaline hydrolysis of diester (10) gives an unstable colourless acid and a stable yellow crypto acid shown by X-ray crystallography to be 3-(2',2'-diphenylethenyl)bicyclo[2.2.l]hepta-2,5-diene-2-carboxylic acid (12). Attempts to convert diesters (2) and acid (12) into derivatives suitable for pyrolytic generation of Ph2C=C=C=C=C=O failed; The mono-acid chloride (14) yielded a small phenylazulene fraction on pyrolysis at 780-800°/0.02 mm.
Collision-Induced Dissociations of Negative-Ions Formed by Reaction of HO- With Alkyl and Aryl Silanes. The Formation of Multiple Bonds to Silicon
Authors: Ohair RA , Bowie JH , Currie GJ
Published: September 2010

Collisional activation of alkyl and aryl siloxide ions produces a variety of ions and neutrals containing double bonds to silicon. Sila enolate ions and sila acyl ions RSi =O are common features of the spectra of alkylsiloxide ions; ab initio calculations suggest these ions to have considerable multiple bond character. It is proposed that most reactions proceed through ion complex intermediates. Specific proton transfer reactions often occur for ions Me3SiCHR (R = C3H5, C3H3 or Ph), i.e. Me3SiCHR → -CH2(Me)2SiCH2R. In the particular case of the formation of PhCH2- from Me3SiCHPh, i.e. Me3SiCHPh → -CH2(Me)2SiCH2Ph → PhCH2- +Me2Si=CH2, the proton transfer competes with scrambling of all hydrogens in the decomposing ion.
Synthesis of Some Thieno Analogs of the Protoberberine and Protopine Skeletons. X-Ray Crystal Structure of 9,10-Dimethoxy-5-methyl-4,5,6,7,12,13-hexahydrothieno[3,2-e][3]benzazeci n-12-one
Authors: Bremner JB , Browne EJ , Engelhardt LM , James GS , White AH
Published: September 2010

The preparation of the tetracyclic derivatives, (5) and (11), thienanalogues of the tetrahydroprotoberberine alkaloids, is described. Cyanogen bromide-induced water solvolysis of these isomeric compounds proceeded by different routes. 9,10-Dimethoxy-4,7,12,12a- tetrahydro-5H-benzo[g] thieno [3,2-a] quinolizine (11) under these conditions gave as the major product 4-(2-hydroxymethyl-4,5- dimethoxybenzyl )-4,5,6,7-tetrahydrothieno[3,2-c]pyridine-5- carbonitrile (12); no azecino derivatives were detected. By contrast such cleavage of 2,3-dimethoxy-5,8,12,12a-tetrahydro-6H- benzo [a] thieno [3,2-g] quinolizine (5) gave a major solvolytic ring- expanded product, 12-hydroxy-9,10-dimethoxy-4,5,6,7,12,13- hexahydrothieno [3,2-e][3]benzazecine-5-carbonitrile (15), and a minor elimination product, (E)-9,10-dimethoxy-4,5,6,7-tetrahydrothieno[3,2- e][3]benzazecine-5-carbonitrile (16). These last two compounds are examples of a new tricyclic ring system. From functional group interconversions of (15) was derived the N- methyl ketone (18), the first thieno analogue of the protopine alkaloid system. The crystal and molecular structure of this compound, 9,10-dimethoxy-5-methyl-4,5,6,7,12,13-hexahydrothieno[3,2-e][3] benzazecin - 12-one (18), has been determined by single-crystal X-ray methods.
1H D.N.M.R. and X-Ray Structure of 2,2-Dimethyl-1-(Para-nitrophenyl)propyl Mesityl Sulfone
Authors: Field LD , Hambley TW , Jacobs BD , Wilson K , Norris RK
Published: September 2010

2,2-Dimethyl-1-(p- nitrophenyl ) propyl mesityl sulfone (3), formed by an SRN1 reaction between sodium mesitylenesulfinate and p-(1-chloro-2,2- dimethylpropyl )nitrobenzene displays a number of conformational interconversions in solution. The activation parameters for the rotation of the mesityl ring about the aryl-sulfur bond and the rotation of the p- nitrophenyl ring about the aryl-carbon bond were determined by 1H d.n.m.r .spectroscopy. The conformation of (3) in the solid state, determined by X-ray crystallography, is very similar to the preferred ground-state conformation of the molecule in solution.
Electronegativity Equalization and the Deformation of Atomic Orbitals in Molecular Wavefunctions
Authors: Magnusson E
Published: September 2010

Electronegativity equalization, which must accompany the formation of a chemical bond, occurs when electronic charge is transferred between the bound atoms but also by changes in the radial dependence of the atomic orbitals involved in the bonding. The degree of contraction or expansion of the atomic orbitals may be studied by analysing ab initio MO wavefunctions calculated with flexible basis sets. The effects on the hydrogen orbital are marked, the 1sHmean radius being progressively reduced by 9-23% across the series of first row
hydrides (BH3 to HF) from its value in the hydrogen atom. The mean radius of the carbon 2p function in the wavefunctions of substituted methanes (CH3BH2
to CH3F) is correspondingly reduced by 2-19% from its free-atom value. Orbital contraction (or expansion) is dependent on bond distance, on the electronegativity difference of the bound atoms, and, because it varies from one MO to another, on the nature of the MO'S. The effects are greatest in MO'S which are strongly bonding.
Synthesis of 2-(5',5'-Ethylenedioxy-1'-methylcyclopent-2'-en-1'-yl)ethanol, and Some 2H-Cyclopenta[b]furan Derivatives Formed by Intramolecular Displacement Reactions
Authors: Campbell M , Collins DJ , James AM
Published: September 2010

Exchange dioxolanation of 2-methyl-2-(prop-2′-enyl)cyclopentane-1,3-done (1b) gave 3,3- ethylenedioxy-2-methyl-2-(prop-2′-enyl) cyclopentan-1-one (2) which, upon reduction and esterification , afforded the epimeric 3,3-ethylenedioxy-2-methyl-2-(prop-2′-enyl) cyclopent-1-yl benzoates (6d). Oxidative cleavage of the terminal double bond in (6d),followed by sodium borohydride reduction yielded
3,3-ethylenedioxy-2-(2'-hydroxyethyl)-2-methylcyclopent-1-yl benzoate (4b) which underwent acid- catalysed rearrangement to 6a-(2′-hydroxyethoxy)-3a- methylhexahydrocyclopenta [b]furan-4-yl benzoate (8b). Flash vacuum pyrolysis of the t- butyldimethylsilyl ether (12), derived from the hydroxy acetal (4b), afforded 3-[2′- (t- butyldimethylsilyloxy )ethyl]-4,4-ethy1enedioxy-3-methylcyclopent-1-ene (14) which upon selective cleavage of the silyl ether group gave 2-(5′,5′-ethylenedioxy-1′-methylcyclopent- 2'′en-1′-y1)ethanol (7). Reaction of the mesylate (16) of (7) with lithium bromide or iodide in tetrahydrofuran at 50-55� for several hours yielded some of the corresponding 3-(2′-haloethyl) compounds (17), but gave mainly the rearranged 6a-(2′-haloethoxy)-3a-methyl-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furans (19a) and (19b). Some related chemistry is described.
A One- and Two-Dimensional 13C and 1H N.M.R. Study of Some Triterpenes of the Hopane, Stictane and Flavicene Groups
Authors: Wilkins AL , Bremer J , Ralph J , Holland PT , Ronaldson KJ , Jager PM , Bird PW
Published: September 2010

The phase sensitive two-dimensional (2D) 13C-1H heteronuclear correlated and double quantum filtered cosy n.m.r. spectra of the triterpenes 7β-acetoxyhopan-22-ol and 2 α,3 β,22 α- triacetoxystictane have been recorded at a resolution sufficient for the complete assignment of their proton resonances. Revisions to some of the methylene proton resonances of 7β-acetoxyhopan-22-ol proposed elsewhere are discussed, and assignments for a series of flavicene and stictane triterpenes are presented. 2D, n.m.r. analyses of a new triterpene isolated from the extracts of the lichen Pseudocyphellaria coronata revealed it to be 22 α-hydroxystictano-25,3 β lactone.
Stereospecificity in the Geminate Recombination of 1,3-Diphenylpropyl Radical Pairs
Authors: Serelis AK , Solomon DH , Steel PJ
Published: September 2010

1,3,4,6-Tetraphenylhexanes (3m) and (3r), formed by the geminate recombination of 1,3- diphenylpropyl (1) radical pairs generated at 90� from diastereomerically pure meso - and rac-1,1′,3,3'-tetraphenylazopropane (2m) and (2r), are obtained
with substantial retention (up to 46% d.e .) of precursor stereochemistry. The stable nitroxyls 1,1,3,3-tetramethylisoindolin-2-yloxyl (4) and 2,2,6,6-tetramethylpiperidin-1-yloxyl (5) were used as scavengers to isolate the geminate reaction (30-35% cage effect). A slight selectivity (64% d.e .) in favour of meso-l,3,4,6-tetraphenylhexane (3m) is found in the encounter reaction of (1). The nature of the molecular motions associated with the partial loss of stereochemistry during the reaction (2) → (1) →(3) is discussed. n.m.r. spectroscopy, particularly 13C, was used for correlating product and precursor stereochemistries and for diastereomer identification. The structural assignments were confirmed by single-crystal X-ray diffraction analysis of (3r).
The Chemistry of Phthalide-3-carboxylic Acid. VI. The Stereochemistry of Some 3-Amino(aryl)methylphthalides and the Derived 3-Aryl-4-hydroxy-3,4-dihydroisoquinolin-1(2H)-ones
Authors: Collins PR , Janowski WK , Prager RH
Published: September 2010

The isomeric 3-[hydroxy(phenyl)methyl]isobenzofuran-1(3H)-ones, of known configuration, have been converted into the corresponding amino and dimethylamino compounds with inversion of configuration, and hence the stereochemistry of these compounds has been determined. The amino compounds have been converted into the corresponding 3-aryl-4-hydroxy-3,4-dihydroisoquinolin-l(2H)-ones, confirming their stereochemical assignments. Attempted displacement of the tosyloxy group in the isomeric 3- [phenyl(toluenesulfonyloxy)methyl]isobenzofuran-l(3H)-ones with dimethylamine proceeded by rearrangement to an epoxy amide and a keto amide.
Preparation of Iodotris(dithiocarbamato)tellurium(Iv) Complexes, and Crystal Structure of Iodotris(piperidine-1-carbodithioato)tellurium(IV)
Authors: Chidambaram S , Aravamudan G , Seshasayee M , Snow MR , Tiekink ERT
Published: September 2010

Mixed iodotris ( dithiocarbamato )tellurium(IV) complexes TeL3I (where L- = R1R2NCS2-) have been synthesized with the use of the oxidative replacement reaction via the interaction of TeL4 with iodine. Thus, complexes with R1 = R2 = methyl, ethyl, isopropyl, propyl, and with R1R2N= piperidinyl * have been prepared. A single-crystal structure analysis of one of these, iodotris ( piperidine dithiocarbamato )tellurium, is also reported. In the structure the tellurium atom exists in a distorted pentagonal-bipyramidal environment with the iodine atom and one sulfur atom occupying axial positions. The axial Te-S bond of 2.555(2) � is shorter than the remaining Te-S bonds in the complex [range 2.671(2)-2.722(2) � ]. Crystals are monoclinic, space group P2I/n with unit cell parameters a 9.891(2), b 18.889(2), c 14.762(2) �, β 98.85(2) and Z 4. The structure was refined to final R 0.035 and RW 0.052 for 3283 reflections with 1≥ 1.25 σI).
Ritter Reactions. V. Further Investigation of the 3-Azatricyclo[5.3.1.04,9]undec-2-ene System
Authors: Bong ICC , Ung AT , Craig DC , Scudder ML , Bishop R
Published: September 2010

2,6-Dimethylenebicyclo[3.3.1] nonane (1) and acetonitrile react under Ritter reaction conditions to produce exo-ll-acetamido-2,4,endo-ll-trimethyl-3-azatricyclo[5.3.1.04,9 ]undec-2-ene (2)monohydrate whose crystal structure [C15H24N2O.H2O, P 21, a 8.21 3(3), b lO.84l(l),c 8.234(2) �, β 95. 57(2)�, Z 2] was determined with a final R 0.036. The diene (1) reacts similarly with benzonitrile to produce the phenyl-substituted analogue (3). In contrast, the reaction of (1) and benzyl cyanide yields a different type of product, 2-benzoyl-4,endo11-dimethyl-exo-11-phenylacetamido-3-azatricyco[5.3.1.04,9]undec-2-ene (5a), where one of the two nitrile -derived groups has undergone spontaneous oxidation during the one-flask preparation. p- Bromo - and p- chloro-benzyl cyanides behave in a similar manner yielding the adducts (5b,c) respectively.
A Novel Composite Polymer Latex Technology
Authors: Leary B , Lyons CJ
Published: September 2010

The physical chemistry involved in the invention and development of a novel aqueous composite polymer latex technology at Dulux Australia is described. The polymerization process employed leads to a latex wherein each particle contains a blend of two or more copolymers. These particles are sterically stabilized by a new class of non-ionic reactive surfactant which results in excellent colloidal stability. A paint based on this technology has been commercialized in the coil coating industry. The particle size distribution of the latex used in this paint is studied before, during and after polymerization. The evidence obtained confirms that the desired composite polymer particles are formed by a suspension polymerization mechanism and that
little or no polymer separation due to secondary nucleation (nucleation of polymer particles from the aqueous phase) takes place.
The Underpotential Adsorption/Deposition and Stripping of Mercury on Gold in Dilute Sulfuric Acid
Authors: Vicentebeckett VA
Published: September 2010

The underpotential deposition of mercury on gold was studied by potentiostatic techniques at a rotating gold ring-disc electrode. Underpotential mercury deposition occurred at potentials more positive than 680 mV (against a dynamic hydrogen electrode). Anodic stripping voltammetry at the disc with ring collection showed that a monolayer coverage of underpotential mercury was equivalent to approximately 370pc/cm2. The stripping process yielded several anodic peaks and produced largely HgII, at least 16% of which remained adsorbed on the bare gold electrode. Potential-step experiments at the disc and ring-shielding data indicated that the underpotential shift was about 500 mV and that the deposition process involved both adsorbed (35-47% of the theoretical monolayer coverage) and soluble mercury(II) species. The adsorbed
mercury had a formal positive charge of 0.40-0.46. The most anodic stripping peak (at 1200 mV) of underpotential mercury may be used to determine nanomolar levels of mercury by anodic stripping voltammetry, by using an overvoltage of less than 100 mV for preelectrolysis.
Highly Selective Oxidation of Hydroquinones to Quinones With Dibenzoyl Peroxide
Authors: Mckay PG , Mitchell AS
Published: September 2010

Dibenzoyl peroxide in the presence of bases such as 1,8-diazabicyclo[5.4.0] undec-7-ene or potassium carbonate oxidizes hydroquinones to quinones cleanly without oxidizing alcohol, aldehyde or benzylic groups.
Skeletal Rearrangements of Deprotonated Organosilanes in the Gas Phase. Silicon-Oxygen Bond Formation
Authors: Downard KM , Bowie JH , Hayes RN
Published: September 2010

Trimethylsilyl anions containing additional alkoxy, ketone or carboxylic acid funtionality undergo a variety of rearrangement reactions upon collisional activation. The most common are those which involve production of Si -O bonds, either by formation of Me3SiO- or by elimination of Me3SiOH.