bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complex Formation of Macrotetrolide Carrier Antibiotics with Cations Studied by Microcalorimetry and Vapour Pressure Osmometry
Authors: Züst Ch. U. , Früh P. U. , Simon W. 
Published: December 2004

AbstractComplex formation parameters of macrotetrolide antibiotics with alkali and alkaline earth metal cations are given. The stability constants for the complexes in methanol and ethanol at 30°, as determined by vapour pressure osmometry, and ΔH0, ΔG0, and ΔS0 for some interactions in methanol and ethanol at 25°, measured by microcalorimetry, are compared and discussed.
Synthese von Haschisch‐Inhaltsstoffen. 6. Mitteilung
Authors: Petrzilka Th. , Demuth M. , Lusuardi W. G. 
Published: December 2004

AbstractThe synthesis of a new (−)‐Δ8‐6a,10a‐trans‐tetrahydrocannabinol analogue, containing a N‐methyl‐3‐propyl‐pyrrolidin‐3‐yl side‐chain, is reported.
Steric Effect in [6+4] Cycloaddition Reactions. Part I
Authors: Pfaendler H. R. , Tanida Hiroshi 
Published: December 2004

AbstractKinetics of cycloaddition of tropone to 6‐methylfulvene and 6,6‐dimethylfulvene were determined. It was concluded that steric effects play a role in [6+4] cycloadditions.
Steric Effect in [6+4] Cycloadditions. Part II
Authors: Pfaendler H. R. , Tanida Hiroshi 
Published: December 2004

Abstract2‐Chlorotropone reacts with 6,6‐dimethylfulvene to form a 1:1 adduct only. From kinetic data as well as from structural evidence the conclusion was drawn that the [6+4] cycloidditions between tropones and cyclopentadiene or fulvenes are highly disfavoured by substituents at the reaction center.
Die Phloroglucide von Dryopteris caucasica (A. Br.) Fraser‐Jenkins et Corley
Authors: Widén C.‐J. , Fraser‐Jenkins C. R. , Lounasmaa M. , v. Euw J. , Reichstein T. 
Published: December 2004

AbstractRhizomes of the recently rediscovered diploid fern Dryopteris caucasica were shown to contain the following phloroglucides: much filixic acid and para‐aspidin, appreciable amounts of desaspidin and traces of flavaspidic acid, trisdesaspidin and aspidinol (artefact), i.e. exactly the same compounds as recently found in D. villarii ssp. villarii. These results are compatible with the hypothesis that either D. caucasica or a member of the D. villarii complex is the second, still unknown, ancestor of the allotetraploid D. filix‐mas (L.) Schott. They also demonstrate the limitations of the chemical method which is quicker but less informative than the classical hybridisation procedures.
Über eine neue Methode zur quantitativen Bestimmung, Reinheitsprüfung und Stabilitätsmessung von Calcium‐Leucovorin
Authors: Suter Hans , Conti Josef , Litmanowitsch Menasche , Grossmann Albert , Hedinger Alfred 
Published: December 2004

AbstractDie Kombination der dünnschichtchromatographischen Auftrennung mit einer spektrophotometrischen Auswertung ergibt eine spezifische quantitative Methode zur Bestimmung von Ca‐Leucovorin. Diese Methode ergibt präzise Resultate auch bei Anwesenheit von weiteren Folinaten. Ein speziell gereinigtes Ca‐Leucovorin wird als neuer hochaktiver Standard vorgeschlagen.
Die Addition von Nucleophilen an Alkinderivate mit Push‐pull‐Gruppen
Authors: Niederhauser Andreas , Frey Alfred , Neuenschwander Markus 
Published: December 2004

AbstractThe preparative aspects of the addition of nucleophiles to alkyne‐derivatives having both push‐ and pull‐groups (1) are discussed: The addition of primary and secondary amines as well of aliphatic alcohols to the alkyne‐derivatives 1 in most cases predominantly yields the Michael‐adducts 2–10. The importance of a side‐reaction consisting in an addition of amines to C(2) of the alkyne‐derivatives 1 increases in the series 1c ≪ 1b < 1a and is controlled by stereoelectronic effects. The spectroscopic properties of the compounds 2–10 are given.
Desoxaphomin, das erste [13]Cytochalasan, ein möglicher biogenetischer Vorläufer der 24‐Oxa‐[14]cytochalasane
Authors: Binder Michael , Tamm Christoph 
Published: December 2004

AbstractFrom cultures of a Phoma species (strain S 298) the hitherto unknown metabolite deoxaphomine has been isolated. On the basis of the spectral data, structure 1 of the (7S, 16R, 20R)‐7,20‐dihydroxy‐16‐methyl‐10‐phenyl‐[13]cytochalasa‐6(12),13t,21t‐triene‐1,23‐dione is assigned to deoxaphomine. This structure is confirmed by the chemical degradation of 1, yielding the products 4 and 6 which are identical with derivatives of phomine (2)((7S,16R,20R)‐7,20‐dihydroxy‐16‐methyl‐10‐phenyl‐24‐oxa‐[14]cytochalasa‐6(12), 13t,21t‐triene‐1,23‐dione) and cytohalasin D (8) ((7S,16S,18R,21R)‐21‐acetoxy‐7,18‐dihydroxy‐16,18‐dimethyl‐10‐phenyl‐[11]sytochalasa‐6(12),13t,19t‐triene‐1,17‐dione). Deoxaphomine (1) is a potential biogenetic precursor of the 24‐oxa‐[14]cytochalasans. Preliminary results of the biological activity of deoxaphomine are reported.
Die Cyclopropylcarbinyl‐Cyclobutyl‐Homoallyl‐Umlagerung II. Teil. Produkte und Geschwindigkeit der Umlagerung von Tricyclo[3.2.1.02,7]octan‐3‐ol‐, endo‐ und exo‐Tricyclo‐[3.2.1.03,6]octan‐4‐ol und exo‐Bicyclo[3.2.1.]oct‐2‐en‐7‐ol‐Derivaten
Authors: Geisel Manfred , Grob Cyril A. , Santi Werner , Tschudi Werner 
Published: December 2004

AbstractSolvolyses of the 2,4‐dinitrobenzoates of the cyclopropylcarbinol 1a, the cyclo‐butanol 2a and the homoallylic alcohol 3a in buffered 70% aqueous dioxane lead to the same product mixture consisting of 78% cyclopropylcarbinol 1a and 22% homoallylic alcohol 3a. Approximately the same product mixture is optained when the homoallylic chloride 3b and the cyclopropylcarbinyl p‐nitrobenzoate 1c are solvolyzed. A common cationic intermediate is indicated in these kinetically controlled rearrangement reactions. Under conditions of thermodynamic control only homoallylic products are formed.The 2,4‐dinitrobenzoates 1d and 2d react 7.2 × 103 and 7.7 times, respectively, as fast as the homoallylic isomer 3d. Since the homoallylic chloride 3b reacts ca. 105 times as fast as its saturated analogue, 7‐exo‐bicyclo[3.2.1]octyl chloride 4, all three esters react with the enhanced rates which are characteristic of these structural types.The endo‐cyclobutyl dinitrobenzoate 2d reacts more than 60 times as fast as its exo‐isomer 6d. The rate difference is ascribed to a stereoelectronically more favorable orientation of the participating σ bonds in the puckered cyclobutane ring in the endo isomer 2d.
Selektive Reduktion von β‐Jonon und Dehydro‐β‐jonon mit Triphenylzinnhydrid
Authors: Wolf Hans Richard , Zink Markus Peter 
Published: December 2004

AbstractThe application of triphenyltinhydride and of triphenyltindeuteride in specific reduction of β‐jonone and dehydro‐β‐jonone has been investigated and the preparation of pure dihydro‐β‐jonone,dihydro‐β‐jonone‐d1, dihydro‐β‐jonone‐d2, and dihydro‐dehydro‐β‐jonone described.
Über Tris(siloxymethyl)‐, Tris(silylmercaptomethyl)‐ und Tris(silylmethyl)amine
Authors: Fink Walter 
Published: December 2004

AbstractBy the reaction of alkali salts of triorgano‐silanols, ‐silanethiols and trimethylsilylmethanol as well as of triorganosilyllithium compounds with tris(chloromethyl)amine, silyl derivatives of tris(hydroxymethyl)‐, tris(mercaptomethyl)‐ and tris(methyl)amine were prepared.
Absolute Konfiguration von α‐Zeacarotin, α‐Apo‐8‐carotinal und α‐Apo‐8‐carotinol
Authors: Buchecker Richard , Eugster Conrad Hans 
Published: December 2004

Abstractα‐Zeacarotene, isolated from corn gluten, has been shown to have the same absolute configuration at C(6) as natural (+)‐α‐carotene. Chiroptical comparison was made with the derived α‐apo‐8‐carotenole. The same chirality has been found with δ‐, ε‐carotene, lutein, semi‐α‐carotenone, zeinoxanthin, crocoxanthin and β,ε‐carotene‐2‐ol. Therefore, biological cyclisation of the acyclic precursor to the α‐ionone ring seems to be stereospecific and is probably different (enantiomeric) to that leading to β‐ionone derivatives.Cotton effects of carotenoids have for the first time been measured in the visible region. All carotenoids examined with C(6)‐R‐chirality show a positive effect at their longest absorption band.
Massenspektren neuer Phloroglucide, insbesondere solcher mit Valerylseitenketten
Authors: Lounasmaa M. , Widén C.‐J. , Reichstein T. 
Published: December 2004

AbstractMass spectra of phloroglucinol derivatives recently isolated from African Dryopteris species are presented. Phloroglucides with n‐valeryl side chain were found in these ferns for the first time. In the mass spectra they show strong peaks corresponding to loss of propene (C3H6) produced by McLafferty rearrangement, as shown in model compounds. Aside of the rottleron change (discussed formerly) this must be considered in order to avoid wrong interpretation, particularly when mass spectra are used to analyse mixtures of homologues, as usually present in the plants. If valeryl side chains are present other methods must be used therefore to measure the amount or show the absence of lower homologues with acetyl side chains.
L'indice de rétention des alcanes isomères en chromatographie en phase gazeuse
Authors: Rappoport Serge , Gäumann Tino 
Published: December 2004

AbstractA method, using the radiolysis of an alkane, for the obtention of a great number of branched hydrocarbons is given. The retention index at 100° as well as its variation with temperature is determined on Apiezon L for 200 alcanes containing between seven and twenty four carbons. It is shown that for branched hydrocarbons the decrease of the retention index is mainly due to the length of the substituent group but also to its position on the chain. Some rules between retention index and molecular structure are deduced that allow the determination of the index of higher branched hydrocarbons. It is also shown that the variation of the retention index with temperature is only a function of the length of the substituent group.
Substoichiometric Extraction of Mercury by Diethyldithiocarbamic Acid
Authors: Wyttenbach A. , Bajo S. 
Published: December 2004

AbstractThe substoichiometric extraction of Hg2+ using diethyldithiocarbamic acid and 203Hg tracer was studied. Chloroform was employed to remove the complexes from the aqueous media which were 0.5M H2SO4 or 1 M HClO4 and 0 to 5 M NaCL. ‐ Systems containing Cl− allowed extraction of Hg2+ for all DDC/Hg molar ratios, the extracted complexes being HgCl(DDC) and Hg(DDC)2. Their exchange constant was determined. ‐ In the absence of Cl−, no extraction could be effected in either system if the DDC/Hg molar ratio was < 1; the H2SO4 system remained clear, whereas a precipitate of HgClO4(DDC) formed in the HClO4 system. For molar ratios > 1, the extraction of Hg2+ increased linearly with the addition of DDC, the extracted complex being Hg(DDC)2.
Aspects of Formation of the D‐Penicillamine‐Antigenic Determinant from Penicilloyl Compounds
Authors: Schneider Conrad H. , Pfeuti Christiane , de Weck Alain L. 
Published: December 2004

AbstractThe formation of D‐penicillamine‐L‐cysteine mixed disulfide from benzylpenicilloic acid, benzylpenilloic acid and benzylpenicilloyl amide derivatives in L‐cysteine suspensions at pH 7,6 and 37° was studied. The reaction is faster than direct penicilloylation of proteins known to be a route to penicilloyl antigenic determinants. The production of S‐bound penicillamine on protein from penicilloyl compounds must therefore definitely be considered as a potential antigenforming step. The reaction may be partly if not fully blocked by acylation of the thiazolidine nitrogen of penicilloyl compounds. When formylation is applied a considerable reduction of the capacity of penicilloyl antigenic determinants to interact with anti‐penicilloyl antibody is noted. A D‐penicillamine‐specific test antigen was prepared by binding D‐penicillamine via thioether links to a partly succinylated poly‐L‐lysine. Clinical test reactions elicited with this conjugate and with penicilloic acid cannot be well correlated. Penicilloic acid probably detects reactions of undefined specificity in addition to D‐penicillamine‐specific ones.
Die Umlagerung substituierter Aminoacrylderivate. Präparative anwendungsbreite
Authors: Niederhauser Andreas , Neuenschwander Markus 
Published: December 2004

AbstractThe addition of carboxylic acids to dimethylamino‐propinal (1a) and 4‐dimethyl‐amino‐but‐3‐in‐2‐on (1b) gives, after rearrangement of the very instable primary adducts (2), Z‐3‐acetoxy‐N,N‐dimethylacrylamides and ‐crotonamides 3 to 8 in excellent yields and in a stereospecific manner. Similarly, the adducts of HCl and HBr to the alkynes 1a and 1b may be rearranged at low temperature by traces of acid to cis/trans equilibria of 3‐halo‐acrylamides and ‐crotonamides 9 and 10. ‐ On the other hand, treatment of 3‐alkoxy‐3‐dimethylaminoacrolein with traces of acid yields alkylesters of E‐3‐dimethylaminoacrylic acid (12, X = OR). ‐ The preparative aspects of the rearrangement are discussed, and a brief outline of the spectroscopic properties of the compounds 3 to 8 is given.
Die Chlorierung des Hexamethyl‐Dewar‐Benzols
Authors: Burger Ulrich , Delay Arlette 
Published: December 2004

AbstractIt has been shown that addition of chlorine to hexamethyl‐Dewar‐benzene is a stereospecific process and yields exclusively 5‐endo‐chloro‐hexamethyl‐bicyclo[2.1.1]hexenyl chloride. This supports the suitability of SbCl5 as a model reagent for olefin chlorination.
Crystal Structure Analysis of a trans, trans‐Cyclodeca‐1, 6‐diene Derivative
Authors: White David N. J. 
Published: December 2004

AbstractAn X‐ray crystal structure analysis of the higher melting diastereoisomer of 2,7‐dibromo‐3,8‐dimethoxy‐trans,trans‐cyclodeca‐1,6‐diene (Monoclinic; a = 5.76, b = 10.43, c = 11.32 Å, β = 94.04°; space group P21/n; Z = 2) has confirmed the NMR. assignment of the molecular conformation and the trans configuration of the methoxy groups. The trans,trans‐cyclodeca‐1,6‐diene ring adopts a centrosymmetric crown conformation with a CCCC torsion angle of 162°.
Thermische Reaktionen mit 3‐Phenyl‐2H‐azirinen; 1, 3‐dipolare Cycloadditionen und En‐Reaktionen
Authors: Narasimhan Nurani S. , Heimgartner Heinz , Hansen Hans‐Jürgen , Schmid Hans 
Published: December 2004

AbstractBenzonitrile p‐nitrobenzylide (5) undergoes 1,3‐dipolar cyclo‐additions in the presence of 3‐phenyl‐2H‐azirines (1), yielding in benzene at 0° 2‐(p‐nitrophenyl)‐4,5‐diphenyl‐1,3‐diazabicyclo[3.1.0]hex‐3‐enes (7, scheme 2). Under the basic conditions of the reaction mixture, 7 a and 7 b are partially converted to 2‐(p‐nitrophenyl)‐4,5‐diphenyl‐1,6‐dihydropyrimidines (8a, b) which are dehydrogenated by oxygen to the corresponding pyrimidines 9a and 9b, respectively.3‐Phenyl‐2H‐azirines (1) form, on heating at 145° in xylene in the presence of the azalactone 32 (2,4‐diphenyl‐Δ2‐oxazolin‐5‐one), 4‐(aziridin‐2′‐yl)‐2,4‐diphenyl‐Δ2‐oxazolin‐5‐ones (33, scheme 11). 33 arises from an ene reaction of the enol form of 32 with 1. Similar ene reactions are observed with the azirines 1 and dimedone (37, scheme 12). Under the ene reaction conditions (xylene, 145°), the non‐isolated intermediate primary adducts (38a and 38b) undergo rearrangements of the vinylcyclopane‐cyclopentene type to give 6,6‐dimethyl‐4‐oxo‐1,3‐diphenyl‐4, 5, 6, 7‐tetrahydroisoindole (40) and 6, 6‐dimethyl‐4‐oxo‐3‐phenyl‐4, 5, 6, 7‐tetrahedroindole (42), respectively.
Nitrierung von 1‐ und 2‐Methoxymethyl‐naphthalin
Authors: Markees Diether G. 
Published: December 2004

Abstract2‐Methoxymethyl naphthalene (1) was synthesized and its properties were found to be different from those reported in the literature. The reaction of this compound with cold conc. nitric acid gave 8‐nitro‐2‐naphthaldehyde (2). When 1‐methoxymethyl naphthalene (4) was treated similarly 4‐nitro‐1‐methoxymethyl naphthalene (5) and 8‐nitro‐1‐naphthaldehyde (6) were obtained.
Synthesis of Potential Ambra Odorants: 5,5,9‐trimethyldecalyl derivatives
Authors: Ohloff Günther , Näf Ferdinand , Decorzant René , Thommen Walter , Sundt Erling 
Published: December 2004

AbstractThe synthesis of racemic stereoisomeric compounds with the 5,5,9‐trimethyldecalin skeleton and an oxygen function at C(1), C(2), or C(3) is describedAlthough racemic decalins are described, only the enantiomer related to steroids is drawn. The projection of the decalins was chosen so as to place the angular methyl group above the plane of the molecule and the oxygen function at C(1), C(2) or C(3) on the left side, as represented by formula 1–6. The relative configuration of the substituents in decalins is designated by using the convention of the steroid series: β, meaning on the same side as the angular methyl group at C(9) and α, meaning on the side opposite from the angular methyl group. The prefix cis or trans refers to the fusion of the decalin ring system, not to the position of the substituents.
. A novel general one‐step synthesis of 2‐decalones by means of acid catalyzed cyclization of acyclic or monocyclic precursors has been developed.
Thermische Umlagerungen von halogensubstituierten Aryl‐propargyläthern
Authors: Šarčevic̀ Nada , Zsindely Janos , Schmid Hans 
Published: December 2004

Abstract7‐Chloro‐2‐chloromethyl‐benzofuran (13) and 3, 8‐dichloro‐2 H‐1‐benzopyran (12) are the main products from the thermal rearrangement (230–260°) of 2, 6‐dichlorophenyl propargyl ether (7). Compounds 17, 18 and 19 are also formed, but in much smaller amounts (scheme 2 and table 1). However, in the case of the bromo‐compounds 8 and 9 the rearrangement products are the benzofuran derivatives 21 and 22, containing one bromine atom less per molecule (scheme 4).The corresponding naphthyl propargyl ethers 10 and 11 can be rearranged much more easily (180°) to the halogeno‐naphthofurans 24 and 26 respectively. In the case of the bromo‐ether 11, 2‐methyl‐naphtho[2, 1‐b]furan (25) is also formed (scheme 5).If the propargylic hydrogen atoms in 7 and 11 are replaced by deuterium atoms, then after rearrangement the deuterium atoms in the products d‐13 and d‐26 are found in the β‐positions to the oxygen atom of the furan ring (schemes 3 and 5).It is suggested that initially a [3s, 3s]‐sigmatropic rearrangement of the aryl propargyl ethers to the 6‐allenyl‐6‐halogeno‐cyclohexa‐2, 4‐dien‐1‐ones (e.g. a) occurs and that from these the isolated products are formed via radical pathways (scheme 6).Under neutral conditions aryl propargyl ethers containing a free ortho‐position give on heating benzopyran derivatives [2]. When this thermal reaction is carried out in sulfolane in the presence of powdered potassium carbonate, 2‐methyl‐benzofuran derivatives are formed (table 2). This leads to the possibility of preparing, depending on the conditions, either benzopyran or benzofuran derivatives by the Claisen rearrangement of aryl propargyl ethers. The mechanism for the formation of the benzofurans is given in scheme 9.
The Synthesis of Damascenone and β‐Damascone and the possible mechanism of their formation from carotenoids
Authors: Isoe Sachihiko , Katsumura Shigeo , Sakan Takeo 
Published: December 2004

AbstractA brief synthesis of damascenone (5) from the acetylenic diol 2 and also that of β‐damascone (8) from β‐ionol, resembling the biogenetic synthesis, are described. A possible mechanism for the formation of damascenone from neoxanthin is proposed.
The Interaction of Walsh‐Orbitols in Diademane and Related Hydrocarbons
Authors: Heilbronner Edgar , Gleiter Rolf , Hoshi Toshihiko , de Meijere Armin 
Published: December 2004

AbstractTo obtain further information concerning the interaction between Walsh‐orbitols of ‘conjugated’ cyclopropane rings, the photoelectron spectra of the following compounds have been recorded: bicyclo[4.1.0]heptane 1, cis‐ and trans‐tricyclo[5.1.03, 5]octane 2, 3, diademane 4, trans‐pentacyclo[3.3.2.02, 9.04, 10, 06, 8]decan 5 and bicyclo[4.1.0]heptene‐2 6. The first bands in the PE.‐spectra of these compounds have been assigned on the basis of a ZDO HMO‐approximation. For 2 and 4 the value for resonance integral between linked 2p atomic orbitals of two adjacent eclipsed cyclopropane rings is found to be −1.73 eV.
A Novel Synthesis of 1‐Aryl‐9‐alkyl‐2, 3, 3a, 4, 9, 9a‐hexahydro‐1H‐pyrrolo[2, 3‐b] quinoxalines by lithium aluminium hydride reduction of N‐phenyl‐1‐benzimidazolyl‐succinimides
Authors: Ahmed Quazi , Wagner‐Jauregg Theodor , Pretsch Ernst , Seibl Josef 
Published: December 2004

AbstractThe N‐substituted 1‐benzimidazolyl‐succinimides 6a–v (Scheme 1, Table 1 and 2) have been prepared by the reaction of benzimidazole and its derivatives with maleimides. Reduction of the N‐cyclohexyl and N‐cyclo‐octyl substituted 1‐benzimidazolyl‐succinimides 6i–k with lithium aluminium hydride gives the normally expected substituted (N‐alkyl‐3‐pyrrolidinyl)benzimidazoles 14i–k. However by LiAlH4‐reduction of the N‐phenyl substituted 1‐benzimidazolylsuccinimides 6a–h mainly the 1‐aryl‐9‐alkyl‐2, 3, 3a, 4, 9, 9a‐hexahydro‐1H‐pyrrolo[2, 3‐b]quinoxalines 7a–h are obtained. The mechanism of this unusual reduction has been elucidated.
N‐Carbobenzoxy‐L‐pyroglutamyl‐L‐histidyl Peptides
Authors: Kurath P. , Thomas A. M. 
Published: December 2004

AbstractN‐Benzyloxycarbonyl‐L‐pyroglutamyl‐L‐histidyl‐peptide reagieren mit Methanol unter Bildung von N‐Benzyloxycarbonyl‐L‐(05‐methyl)glutamyl‐L‐histidyl‐peptiden (Hauptprodukte) und L‐Pyroglutamyl‐L‐histidyl‐peptiden (Nebenprodukte), wenn die basische Histidin‐Seitenkette nicht protoniert ist. Solche basenkatalysierte Methanolysen. wurden an einem Di‐ und an einem Tripeptid‐Amid beobachtet. Die entsprechende Äthanolyse verlauft wesentlich langsamer.
Komplexone XLVI. EDTA‐Komplexe des Pt(II)‐Ions mit und ohne einzähnige Fremdliganden
Authors: Stünzi Hans , Anderegg Giorgio 
Published: December 2004

AbstractThe formation of complexes between Pt(II)EDTA2− and H+, OH−, Cl−, Br−, SCN−, CN− and NH3 was investigated using pH and UV.‐spectrophotometric measurements at ionic strength 1.0 and 25°. The existence of the following species could be proved (charges are omitted): HpPt(EDTA) (0 ≤ p ≤ 3), Pt(EDTA)X (X = OH, NH3, Cl, Br, I, SCN), HpPt(EDTA)X (1 ≤ p ≤ 3; X = Cl, Br) and H4Pt(EDTA)Cl2. They have been characterised by spectral data as well as with equilibrium constants. The different modes of attachment of EDTA are discussed.
Nuclear Quadrupole Resonance and Stereochemistry III. Trichloromethyl derivatives
Authors: Ardalan Ziba , Lucken Edwin A. C. 
Published: December 2004

Abstract35Cl nuclear quadrupole resonance frequencies are reported of the chlorine atoms in the trichloromethyl group of benzotrichlorides and trichloromethyl derivatives of heterocyclic molecules. They are compared with previously reported results for the same group attached to other planar conjugated radicals. In such compounds the three chlorine atoms cannot be equivalent and all the results are discussed from the point of view of possible orientation‐dependant hyperconjugation between the CCl bonds and the conjugated moiety, particularly with reference to the marked effects observed in trichloromethyl ethers reported in part I of this series. In the benzo‐trichloride and indeed most of the compounds discussed such effects are small.