bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Auslösung von Fenton‐Reaktionen durch cytotoxische Methylhydrazin‐Verbindungen
Authors: Berneis K. , Kofler M. , Bollag W.
Published: December 2004

Ultracentrifugal studies demonstrate that cytotoxic methylhydrazine derivatives such as 1‐methyl‐2‐benzyl‐hydrazine break down nucleic acids much more than added hydrogen peroxide in solution of low content of iron ions. It is further shown that the methylhydrazine derivatives mentioned increase the reactivity of hydrogen peroxide towards deoxyribose. The conclusion is that the cytotoxic methylhydrazine derivatives not only produce hydrogen peroxide but that they also promote reactions between hydrogen peroxide and organic compounds. The latter effect is ascribed to the initiation of FENTON chain reactions by the methylhydrazine derivatives or by the free radicals formed in the course of their autoxidation. The relevance of these results to the biological activity of the methylhydrazine derivatives has not yet been established.
Die Synthese des Ergosins und des Valin‐Analogen der Ergotamin‐Gruppe. 61. Mitteilung über Mutterkornalkaloide
Authors: Stadler P. A. , Frey A. J. , Ott H. , Hofamann A.
Published: December 2004

The total synthesis of ergosine, a naturally occurring ergot alkaloid, and of ergovaline, which contains valine as the variable amino acid of the peptide part and has not been found in nature yet, is described in accordance with the process developed for the synthesis of ergotamine.
Die Cardenolide der Samen von Antiaris toxicaria Lesch. 1. Mitteilung: Isolierungen und Identifizierungen Glykoside und Aglykone, 258. Mitteilung
Authors: Mühlradt P. , Weiss Ek. , Reichstein T.
Published: December 2004

In den Samen von Antiaris toxicaria LESCH. liessen sich nach fermentativem Abbau mit den sameneigenen Fermenten 34 Cardenolide nachweisen. 16 konnten nach chromatographischen Trennungeii in Kristallen isoliert werden. Von diesen liessen sich 10 mit bekannten Cardenoliden identifizieren, 6 waren neu. Ihre Struktur liess sich teilweise aufklären. ‐ Der Vergleich ergibt, dass die Samen wesentlich andere Glykoside produzieren, als sie früher im Latex derselben Pflanze gefunden wurden. Erheblich verschieden sind vor allem die Zucker. In den Samen wurden Derivate der 6‐Desoxy‐D‐allose sowie eines neuen Zuckers, der Javose gefunden.
Cycloenantiomerie und Cyclodiastereomerie. 1. Mitteilung
Authors: Perlog V. , Gerlach H.
Published: December 2004

Two novel concepts, cycloenantiomerism and cyclodiastereomerism, are introduced and exemplified by cyclic compounds containing equal numbers of enantiomeric chirality centers.
Synthetische Analoge des Hypertensins. V. α‐L‐,β‐L‐, α‐D‐ und β‐D‐Asp1‐Val5‐Hypertensin II; Desamino‐Val5‐Hypertensin II
Authors: Riniker B. , Schwyzer R.
Published: December 2004

The preparation of the 4 isomeric octapeptides α‐L‐,β‐L‐, α‐D‐, and β‐D‐Asp1‐Va15‐hypertensin II, and of their parent compound, desamino‐Val5‐hypertensin II, is described.
Die Komplexchemie des Methylquecksilber‐Kations
Authors: Schwarzenbach G. , Schellenberg M.
Published: December 2004

The stability constants of the methylmercury complexes CH3HgL1−λ with a considerable number of ligands Lλ− have been determined (Table 1). Like H+, the cation CH3Hg+ reveals the coordination number 1 almost exclusively. Some ligands form also binuclear adducts (CH3Hg)2L2−λ and sulfide even forms (CH3Hg)3S+. The coordination behaviours of CH3Hg+ and H+ however are very different concerning the selection of ligands, the former being a soft and the latter a hard acid in the sense of PEARSON. The entropy ΔS of the reaction: H+ + L− → HL is more positive by about 14 c.u. than ΔS of the reaction: CH3HG+ + L− → CH3HgL. The hydrogen ion in aqueous solution has a far greater order producing action on the solvent than CH3Hg+. Two dyes also have investigated, which may serve as indicators for CH3HG+ and for the determination of pCH3Hg (= −log[CH3Hg+]).
Über die Struktur von Verrucarin B. Verrucarine und Roridine, 6. Mitteilung
Authors: Gutzwiller J. , Tamm Ch.
Published: December 2004

For verrucarine B (C27H32O9), a companion of the antibiotic verrucarine A, structure 1 is proposed. In verrucarine B an epoxy group replaces the hydroxyl group of verrucarine A.
Röntgenkontrastmittel. 6. Mitteilung. Jodierte Derivate der 3‐Aminomethyl‐benzoesäure
Authors: Felder E. , Pitré D. , Fumagalli L.
Published: December 2004

A number of mono‐ and of diacylated 3‐aminomethyl‐5‐amino‐2,4,6‐triiodobenzoic acids have been synthesized for evaluation as X‐ray contrast agents. 3‐Acetamidomethyl‐5‐acetamido‐2,4,6‐triiodobenzoic acid seems to be a promising urographic agent [1].
Die Struktur des Alkaloids C‐Calebassin
Authors: Fehlmann M. , Koyama H. , Niggli A.
Published: December 2004

The crystal structure determination of C‐calebassine iodide C40H48O2N4I2,nH2O has shown that the structure of the alkaloid ion is in agreement with formula Ia, proposed by P. KARRER et al. [3] (cf. structure formula). As the refinement is still going on, further details will be published in Z. Krist.
Neue Synthese von Lactamen der Dibenz[b,f]‐1,4‐thiazepin‐, ‐oxazepin und Dibenz[b, e]‐azepin‐Reihe. 4. Mitteilung über siebengliedrige Heterocyclen
Authors: Schmutz J. , Künzle F. , Hunziker F. , Bürki A.
Published: December 2004

By intramolecular application of LEUCKART's amide synthesis using isocyanato‐diphenylsulphides, ‐diphenyloxides and ‐diphenylmethanes with AlCl3 in o‐dichlorobenzene a method has been found which gives in very good yields 10,11‐dihydro‐11‐oxo‐dibenz[b,f]‐1,4‐thiazepines (VII), ‐oxazepines (VIII), and 5,6‐Dihydro‐6‐oxo‐dibenz[b,e]‐azepines (XI), respectively.
Notiz über ringbildende Kondensationen von Homophtalsäure‐dimethylester mit α,β‐ungesättigten Carbonylverbindungen
Authors: Eisenhuth W. , Renfroe H. B. , Schmid H.
Published: December 2004

Es werden basenkatalysierte Kondensationen von Homophtalsäure‐dimethylester mit einigen α,β‐ungesättigten Carbonylverbindungen beschrieben, die zu neuen hydroaromatischen Ringverbindungen führen. Das mit Cumarin entstehende Kondensationsprodukt hat man dehydriert und einigen weiteren Reaktionen unterworfen.
Struktur von Coleon A
Authors: Karanatsios D. , Eugster C. H.
Published: December 2004

Für Coleon A, das Hauptpigment aus den Blättern von Coleus igniarius SCHWEINF. (Labiatae), wird die Struktur I bewiesen. Es wird die Vermutung ausgesprochen, dass es biogenetisch ein hoch oxydiertes Derivat eines 1,10‐seco‐Diterpens der Abietanreihe vorstellt. Zur Festlegung der relativen Substituentenanordnung im Chinonteil hat sich die Methode der Überführung in Indenoncarbonsäuren als geeignet erwiesen. Neben Coleon A und B sind die optisch aktiven Coleus‐Substanzen C und D, beide C30H50O, isoliert worden. Es wird auf die Tatsache hingewiesen, dass oxydierte und modifizierte Diterpene bisher vor allem in Vertretern der Labiaten aufgefunden worden sind.
Restlose Überführung organischer Verbindungen in gasförmige Produkte zur gleichzeitigen Bestimmung von 3H und 14C in Proportionalzählrohren
Authors: Jordan P. , Lykourézos Ph. A. P.
Published: December 2004

Zur gleichzeitigen Bestimmung von 3H und 14C in organischen Substanzen durch Gas‐Proportionalzählung wird ein pyrolytisches Verfahren beschrieben, welches erlaubt, den Wasserstoff und den Kohlenstoff dieser Substanzen in einer einzigen Operation restlos in gasförmige Reaktionsprodukte überzuführen.
Bullosid (Teilstruktur). Glykoside und Aglykone, 266. Mitteilung
Authors: Duncan G. R. , Weiss Ek. , Reichstein T.
Published: December 2004

Bulloside was found to be the glycoside of digitoxigenin with a disaccharide. The latter ist most probably either thevetosido‐digitoxose, not yet known in pure state, or a stereoisomer of this biose.
Stoffwechselprodukte von Mikroorganismen 49. Mitteilung. Die Ferrioxamine A1, A2 und D2
Authors: Keller‐Schierlein W. , Mertens P. , Prelog V. , Walser A.
Published: December 2004

The structures of the ferrioxamines A1, A2, and D2, minor components of the sideramine mixtures from cultures of Streptomyces, have been determined by degradation and, in part, by synthesis. Whereas the previously investigated ferrioxamines B, D1, E, and G contain but a single basic component, 1‐amino‐5‐hydroxylaminopentane, the ferrioxamines A1, A2, and D2 contain in addition to this base its lower homologue, 1‐amino‐4‐hydroxylamino‐butane.
Über die Isolierung von Verrucarin H, Verrucarin J, Roridin D und Roridin E aus Myrothecium‐Arten. Verrucarine und Roridine, 8. Mitteilung
Authors: Böhner B. , Fetz E. , Härri E. , Sigg H. P. , Stoll Ch. , Tamm Ch.
Published: December 2004

From cultures of Myrothecium verrucaria (ALBERTINI et SCHWEINITZ) DITMAR ex FRIES and Myrothecium roridum TODE ex FRIES four additional metabolites have been isolated: verrucarin H (C29H36O8), verrucarin J (C27H32O8), roridin D (C29H38O9) and roridin E (C29H38O8). They are closely related to verrucarin A and B, since they contain the sesquiterpenoid alcohol verrucarol as structural element.
Beiträge zur Chemie der Carotinoide. 3. Mitteilung Darstellung von 5‐Hydroxy‐5,6‐dihydro‐β‐carotin
Authors: Grob E. C. , Siekmann W.
Published: December 2004

By reduction of β‐Carotene‐monoepoxide with LiAlH4 we have obtained a product with the probable structure of 5‐Hydroxy‐5,6‐dihydro‐β‐carotene, as deduced from visible, IR. and NMR. spectra, as well as from thinlayer‐chromatography data.
Synthesen in der Polymyxinreihe. 10. Mitteilung. Die Synthese von Colistin A (Polymyxin E1)
Authors: Studer R. O. , Lergier W. , Lanz P. , Böhni Erika , Vogler K.
Published: December 2004

Colistin A (Polymyxin E1), an antibiotic isolated in 1950 from cultures of B. colistinus, is shown by synthesis to have the cyclo‐heptapeptide structure VI (Figure 1) already proposed by other workers on the evidence of degradation studies.
Synthese von All‐D‐Val5‐Angiotensin II‐Asp1‐β‐Amid
Authors: Vogler K. , Studer R. O. , Lergier W. , Lanz P.
Published: December 2004

The synthesis of all‐D‐Val5‐Angiotensin II‐Asp1‐β‐Amide (Scheme 2), the antipode of the active principle of Hypertensin CIBA®, is carried out according to known schemes in the L‐series. It showed neither inhibitory nor angiotensin‐like effects up to concentrations of 10−3.
Zum Stoffwechsel von Noveril®: 14C‐Markierung und Synthese von Metaboliten 6. Mitteilung über siebengliedrige Heterocyclen
Authors: Hunziker F. , Schindler O.
Published: December 2004

5‐Methyl‐10‐β‐dimethylamino‐ethyl‐10, 11‐oxo‐5H‐dibenzo[b, e]‐1,4‐diazepin (I; base of Noveril®) has been labelled with 14C in the basic side chain for the purpose of metabolism studies. The synthesis of several postulated metabolites has also been described.
Photochemische Reaktionen. 31. Mitteilung. [1]. Die photochemische Isomerisierung von C(‐10)‐diastereomeren 3‐Oxo‐Δ1;5‐Steroiden
Authors: Nann B. , Wehrli H. , Schaffner K. , Jeger O.
Published: December 2004

The photochemical transformation of 3‐oxo‐17β‐acetoxy‐Δ1;5‐androstadiene (2) and its 10α‐diastereoisomer 7 has been investigated. With low conversion of 2, an isomer was produced for which structure 8 (6β‐H) is proposed. After longer photolysis times, both compounds, 2 and 8, were consumed, and the four stereoisomeric photoproducts 9–12 were obtained. Products 9 and 10 on one hand, and 11 and 12 on the other, are photochemically interconvertible. Dienone 7 yielded a very similar product mixture from which ketones 10 and 12 could be isolated. Further, the presence of a dienone isomer was demonstrated to which structure 8 (6α‐H) is assigned.
Sur la composition de l'arôme de café [1]
Authors: Viani R. , Müggler‐Chavan F. , Reymond D. , Egli R. H.
Published: December 2004

A gas‐chromatographic investigation of coffee aroma has revealed, besides 34 known components, the presence of 4 new substances: 2,3‐dimethylpyrazine, γ‐buty‐rolactone, O‐acetylacetol and hexane‐2,3‐dione. The fragmentation pattern of 2‐Methyl‐tetrahydrofuran‐3‐one, a known component of coffee aroma, has been determined by means of high resolution mass spectrography.
Herstellung hydrierter Produkte aus 1‐Acetyl‐2, 6‐dioxo‐2, 3, 4, 6‐tetrahydro‐pyrido [2, 1‐a] isoindol. 2. Mitteilung [1]
Authors: Viscontini M. , Kaiser W.
Published: December 2004

1‐Acetyl‐2,6‐dioxo‐2,3,4,6‐tetrahydro‐pyrido[2,1‐a]isoindol (II) liefert bei der katalytischen bzw. NaBH4‐Reduktion zwei Tetrahydro‐stereoisomere VII und X, deren Konfiguration und Konformation mit Hilfe von IR.‐ und NMR.‐Spektren aufgeklärt wurden.
Note sur la décomposition du nitrate de triphénoxyméthylphosphonium
Authors: Hudson R. F. , Chopard P. A.
Published: December 2004

In the course of the decomposition of triphenylphosphonium nitrate, the adduct of two molecules of phenol with one molecule of benzoquinone was isolated in small yields. The benzoquinone is probably produced by radical oxidation of phenol by nitrogen pentoxide, itself produced by reaction between nitrate ions and the quasiphosphonium nitrate, postulated as an intermediate in the main reaction leading to a mixture of o‐ and p‐nitrophenols.
Réactions du diazométhane II. Transformation de la fonction N‐(phénylthio‐carbonyle) de la N‐(phénylthio‐carbonyl)‐aniline avec production de phénylthio‐acétanilide par insertion
Authors: Baudet P. , Calin M. , Cherbuliez E.
Published: December 2004

The reaction of diazomethane with N‐(phenylthio‐carbonyl)‐aniline gives on the one hand phenylthio‐acetanilide and on the other N‐phenylpropiolactame. This β‐lactame arises by the (known) addition of two molecules of diazomethane to phenyl isocyanate, the latter resulting by an elimination (E2) of the thiophenyl residue in the form of thio‐anisole, originating from the direct action of diazomethane on the N‐(phenylthio‐carbonyl) group. The acetanilide is produced by the insertion of a methylene group (furnished by diazomethane) with fissure of the sulphur‐carbon linkage in the grouping It is probable that the mechanism of the transformation involves, as a first step, a bimolecular nucleophilic substitution on the carbonyl of the carbamate function, yielding a diazonium cation and a thiophyl anion; in a second step the diazonium ion reacts with the anion C6H5S⊖, establishing the linkage SCH2 with elimination of nitrogen.
Étude de la structure, par la diffraction des rayons X et la microscopie électronique, de l'hydroxylapatite calcique et des orthophosphates dits tri‐ et octocalciques
Authors: Vuilleumier Cl. , Lerch P.
Published: December 2004

La structure des orthophosphates de calcium étudiés, obtenus par diverses méthodes à l'état microcristallin, a été examinée à l'aide de la diffraction des rayons X et des électrons, du microscope électronique, de la mesure de la surface spécifique, de la thermogravimétrie et de l'analyse thermique différentielle. Les dimensions et les surfaces spécifiques des microcristaux et de leurs agrégats ont été déterminées; quant à la forme et à l'orientation des axes des microcristaux, il s'agit de longues aiguilles prismatiques à base hexagonale pour l'hydroxylapatite calcique et pour le phosphate tricalcique hydraté; le phosphate dit octocalcique est au contraire formé par des plaques, à cǒté d'un important matériel amorphe. Les résultats obtenus à I'aide de méthodes de diffraction et de la micrographie électronique appliquées à des produits chauffés à diverses températures jusqu' à 1000° confirment ceux de la thermogravimétrie et de l'analyse thermique différentielle.
Synthèse de la désamino1‐Arg8‐vasopressine et de la désamino1‐Phe2‐Arg8‐vasopressine, deux analogues possédant une activité antidiurétique plus élevée et plus sélective que celle des vasopressines naturelles
Authors: Huguenin R. L. , Boissonnas R. A.
Published: December 2004

Deamino1‐Arg8‐vasopressin and deamino1‐Phe‐2Arg8‐vasopressin have been synthesized by condensation of L‐glutaminyl‐L‐asparaginyl‐S‐benzyl‐L‐cysteinyl‐L‐prolyl‐G‐tosyl‐L‐arginyl‐glycinamide with β‐benzylthio‐propionyl‐L‐tyrosyl‐L‐phenyl‐alanylazide and β‐benzylthio‐propionyl‐L‐phenylalanyl‐L‐phenylalanylazide, respectively. After removal of the protecting groups and oxidation with hydrogen peroxide, the deamino‐nonapeptides have been purified by counter‐current distribution. Deamino1‐Arg8‐vasopressin as well as deamino1‐Phe2‐Arg8‐vasopressin exhibit a higher antidiuretic activity (1300 IU/mg and 800 IU/mg, respectively) and a lower pressor activity than arginine‐vasopressin. This confers to both analogues, and especially to the latter, a remarkable selectivity of the antidiuretic action.
Stoffwechselprodukte von Mikroorganismen. 50. Mitteilung. Die Konfiguration der Arcanose
Authors: Roncari G. , Keller‐Schierlein W.
Published: December 2004

The L‐xylo configuration of arcanose, a sugar from the antibiotic lankamycin, has been proven by its transformation into cladinose. The determination of the absolute configuration at C‐3 of arcanose and cladinose has been accomplished utilizing a new procedure.
Hydrolyse und Alkoholyse von Reaktivfarbstoffen: I. Hydrolyse von Dichlortriazin‐Farbstoffen. 1. Mitteilung über reaktionsmechanistische Untersuchungen an Reaktivfarbstoffen
Authors: Rys P. , Zollinger Hch.
Published: December 2004

The kinetics of the hydrolysis of a dichlorotriazine reactive dye have been determined in aqueous buffer solutions at pH values between 8.50 and 13.47, at 24.0° and ionic strength I = 0.625.

The reaction order with respect to the concentration of the dye and the hydroxyl ions is a complex function of the reaction conditions.

Only in very dilute solutions the kinetics follow the mechanism postulated by Ackermann and Dussy [4].

Several types of base catalysis can be detected, depending on conditions (pH, concentrations).
Synthesen von Chinoxalin‐Derivaten
Authors: Zellner H. , Zellner G.
Published: December 2004

Es werden in 1‐Stellung benzylierte und phenyläthylierte 3‐Benzyl‐1,2‐dihydrochinoxalin‐2‐one, 1,6,7‐trisubstituierte 1,2‐Dihydrochinoxalin‐2‐one und ‐3‐Methyldihydrochinoxalin‐2‐one, verätherte 2‐Hydroxy‐chinoxaline, sowie 1,2,3,4‐Tetrahydrochinoxaline und deren Quartärisate beschrieben, die zwecks pharmakologischer Prüfung synthetisiert wurden.
Zum Zusammenhang zwischen Ligand‐Acidität und Metallkomplex‐Stabilität: Abnehmende Stabilität bei zunehmender Basizität
Authors: Sigel H. , Kaden Th.
Published: December 2004

The increase of the stability of metal ion complexes with decreasing basicity of the ligands within different series is discussed with the help of the equation of IRVING & ROSSOTTI [4] [12] and explained in terms of the free energy G of the complexes.
Sur la composition de l'arôme de thé
Authors: Müggler‐Chavan F. , Viani R. , Bricout J. , Reymond D. , Egli R. H.
Published: December 2004

A gas‐chromatographic investigation of black tea aroma has revealed, besides 19 known components, the presence of 4 new substances: 1‐penten‐3‐ol, trans‐2‐hexen‐1‐ol, α‐terpineol and β‐ionone. The fragmentation pattern of 1‐penten‐3‐ol has been determined by means of high resolution mass spectrography.
Einsatz gas‐chromatographischer Kolonnen hoher Trennleistung in direkter Kombination mit Massenspektrometer
Authors: Völlmin J. A. , Omura I. , Seibl J. , Grob K. , Simon W.
Published: December 2004

A routine instrument for the combination of a single focusing mass spectrometer with high efficiency tubular as well as packed GC columns using a molecule separator is described. The application of the unit in the analysis of cigarette smoke is given.
Zerfall der Dimeren des Acenaphtylens als Folge der Alkalimetall‐Reduktion
Authors: Gerson F. , Weidmann B.
Published: December 2004

Trans‐ and cis‐dinaphthylene‐cyclobutane formed by photodimerisation of acenaphthylene are shown to produce the radical anions of the monomer on sodium reduction. This is explained in terms of the large energy difference between the lowest antibonding MOs of the dimers and of the monomer.
Synthese und Abbau von 1‐(5‐Nitro‐2‐thiazolyl)‐2‐imidazolidinon und Derivaten
Authors: Wilhelm M. , Marquardt F.‐H. , Meier Kd. , Schmidt P.
Published: December 2004

1‐(5‐Nitro‐2‐thiazolyl)‐2‐imidazolidinone is synthesized from 2‐amino‐5‐nitro‐thiazole and 2‐chloroethyl‐isocyanate. The structure of this new potent schistosomicide is established by acid and alkaline degradation as well as by synthesis starting from 2‐imidazolidinone. A number of derivatives of 1‐(5‐nitro‐2‐thiazolyl)‐2‐imidazolidinone are reported.
Organische Phosphorverbindungen. XXVII Die direkte Synthese von Tetramethylphosphoniumhalogeniden
Authors: Maier Ludwig
Published: December 2004

The reaction of methyl chloride and methyl bromide with white phosphorus is studied under a variety of conditions, and the conditions giving a high yield of tetramethylphosphonium chloride and bromide are established. Thermal decomposition of [(CH3)4P]+Cl− gives (CH3)3P and CH3Cl, and alkaline decomposition of [(C4H9)3(C12H25)P]+Cl− gives C4H10 and (C4H9)2(C12H25)PO.
Die Cardenolide von Antiaris toxicaria LESCH Identifizierung von «Bogorosid» mit Convallosid sowie Isolierung und Partialsynthese von Gluco‐periplorhamnosid. Glykoside und Aglykone, 283. Mitteilung
Authors: Brandt R. , Kaufmann H. , Reichstein T.
Published: December 2004

Bogoroside, a hitherto unidentified glycoside from Antiaris toxicaria LESCH, is shown to be identical with convalloside. Reduction of the aldehyde group in convalloside to the methyl group yielded gluco‐periplorhamnoside, which could also be isolated from the sap of Antiaris toxicaria.
Notiz über thermische Ummethylierungsreaktionen. 5. Mitteilung über das massenspektrometrische Verhalten quartärer Stickstoffverbindungen
Authors: Hesse M.
Published: December 2004

Die beiden Methylgruppen von Yohimbin‐methochlorid (1) sind thermisch austauschbar, was an Hand der trideuterierten Verbindung 2 massenspektrometrisch gezeigt wird. Die N(b)‐Trideuteromethylgruppe von 2 ist auch auf das «dimere» Indolalkaloid Voacamin (3) thermisch übertragbar.
Die Röntgenstrukturanalyse von 17β‐Bromacetoxy‐ 9β, 10α‐androst‐4‐en‐3‐on
Authors: Oberhänsli W. E. , Robertson J. Monteath
Published: December 2004

The structure of 17β‐bromacetoxy‐9β, 10α‐androst‐4‐en‐3‐one has been determined by three‐dimensional X‐ray crystallographic methods. The crystals of the restrosteroid belong to the orthorhombic space group P212121 with four molecules per unit cell. The cell constants are a = 11.32 Å, b = 13.71 Å and c = 12.52 Å. The absolute configuration of the molecule has been determined by the anomalous dispersion method. Bond length, bond angles and distances of atoms from ‘best planes’ are given. Ring A represents a distorted half‐chair, ring B and C a chair and ring D an envelope conformation. The molecule shows, contrary to normal 9α, 10β‐steroids, a bent shape.
Protonenresonanzspektroskopische Untersuchungen an Bicyclo [2.2.1]heptan‐ und Bicyclo[2.2.2]octan‐Derivaten: Einfluss von Substituenten auf die chemische Verschiebung
Authors: Pretsch E. , Immer H. , Pascual C. , Schaffner K. , Simon W.
Published: December 2004

The influence of substituents on the chemical shifts of protons in bicyclo[2.2.1]‐heptanes and bicyclo[2.2.2]octanes is discussed. A linear correlation between the change in chemical shift of a proton, due to a neighbouring methyl group, and the distance between this proton and the methyl group is obtained.
Über in 11‐Stellung amino‐substituierte Dibenzo[b,f]‐1, 4‐thiazepine und ‐oxazepine. 9. Mitteilung über siebengliedrige Heterocyclen
Authors: Schmutz J. , Künzle F. , Hunziker F. , Gauch R.
Published: December 2004

Neuroleptics are found in the 11‐amino substituted dibenzo[b,f]‐1, 4‐thiazepine and dibenzo[b,f]‐1, 4‐oxazepine series III. They may be synthesized by aminolysis of the iminochlorides VI and/or by Bischler‐Napieralski ring closure of the urea II with POCl3.
Über die photochemische Cyclisierung von 2‐Allylphenolen
Authors: Fráter Gy. , Schmid H.
Published: December 2004

A series of 2‐allyl‐phenols and 2‐but‐3′‐enyl‐phenol were photochemically rearranged to the corresponding cyclic ethers. The isomer distribution was shown to be similar to that observed for the acid catalysed cyclisation.
Recherches sur la formation et la transformation des esters LXXII. Aryl(ou aralcoyl ou alcoyl)amino‐2‐tétrahydro‐m‐thiazines ou aryl(ou aralcoyl ou alcoyl)amino‐2‐dihydro‐Δ2‐m‐thiazines et dérivés
Authors: Cherbuliez Emil , Baehler Br. , Espejo O. , Jindra H. , Willhalm B. , Rabinowitz J.
Published: December 2004

3‐Aminopropanol reacts with aryl(or aralkyl or alkyl)isothiocyanates RNCS to yield the corresponding thio‐ureas RNHCSNH(CH2)3OH which, refluxed with hydrochloric acid, are cyclized by elimination of water. The cyclization products are identical with the hydrothiazines resulting by elimination of sulfate or phosphate from the sulfuric or phosphoric monoesters of these thio‐ureas. The resulting hydrothiazines are either 2‐(R‐imino)‐tetrahydro‐m‐thiazines (I) or 2‐(R‐amino)‐dihydro‐Δ2‐m‐thiazines (II). Their structure has been established by comparison of their spectra with those of model compounds in one of which the CN double bond is certainly endocyclic (2‐methyl‐dihydro‐Δ2‐m‐thiazine), the other presenting an exocyclic CN double bond (3‐methyl‐2‐phenylimino‐tetrahydro‐m‐thiazine). When R is an aryl group, the CN double bond is exocyclic (structure I with >CNAr), and one may presume that this structure is stabilized by resonance. When R is an aralkyl or an alkyl group, the CN double bond is endocyclic (structure II). The nmr spectra were taken with three types of solvent: CDCl3 or CCl4; (CD3)2SO; CF3COOH. In CF3COOH solution the benzylic protons of the hydrothiazine with R = pFC6H4CH2 couple with NH (J=5,5cps) which confirms the endocyclic position of the CN double bond in this case.
Les spectres de masse dans l'analyse 9e communication [1] Le réarrangement de doubles liaisons sous bombardement d'électrons
Authors: Willhalm B. , Thomas Alan F.
Published: December 2004

Using suitably deuteriated olefins, it is shown that electron bombardment of compounds having double bonds exocyclic to six‐membered rings apparently causes migration of the double bond into the ring. Isopropenylcyclohexanes, on the other hand, appear to behave as if the radical were fixed on the terminal carbon, while the charge migrates by 1,2 hydrogen transfers.
Die Bestimmung der Energiebarriere für die gehinderte interne Rotation in N, N‐Dimethylformamid durch Protonenresonanz‐Spektroskopie
Authors: Conti F. , von Philipsborn W.
Published: December 2004

A re‐determination of the energy barrier for the internal rotation of N, N‐dimethylformamide has been carried out by proton magnetic resonance under refined experimental conditions. Consistent data have been obtained for ΔE, ΔG≠, and v0 from different experiments utilizing 60 Mc/s and 100 Mc/s spectrometers including homonuclear double resonance and the use of deuterium substitution. The results are compared with the range of values previously reported in the literature.
Interaction entre les phosphites alcoylés et le groupe carbonyle; trransformation des phosphites méthyliques dans l'acide acétique
Authors: Chopard P. A.
Published: December 2004

In acetic acid, trimethyl phosphite dealkylates and simultaneously forms dimethyl (1‐dimethoxyphosphono‐ethyl) phosphate. This is interpreted as evidence of an attack at the carbonyl group of the carboxylic acid.
Studien über Benzthiazole als eventuelle orale Antidiabetica
Authors: Suter Hans , Zutter Hans
Published: December 2004

Es wurden neue Vertreter der Benzthiazolyl‐harnstoffe, Benzthiazolylaminoessigsäureamide, Benzthiazolyl‐thioessigsäureamide, Benzimidazolyl‐thioessigsäureamide und Benzthiazolylsulfonyl‐harnstoffe synthetisiert. Keine der hergestellten Verbindungen war genügend hypoglykämisch, um eine eingehende Prüfung zu rechtfertigen.
Gas‐chromatographische Untersuchungen an Uronsäuren und Uronsäurederivaten
Authors: Raunhardt O. , Schmidt H. W. H. , Neukom H.
Published: December 2004

Das gas‐chromatographische Verhalten der Per‐trimethylsilyl‐Derivate einiger natürlich vorkommender Uronsäuren bzw. Uronolactone, ihrer Salze, ihrer Reduktions‐(Onsäuresalze und‐γ‐lactone) und Oxydationsprodukte (Glycarsäuren bzw. ihre Salze und Lactone) sowie ihrer Reaktionsprodukte mit Methanol wurde auf den Silikongummi‐Kolonnen SE‐52 und SE‐30 untersucht. Die beim Kochen von D‐Mannuron, D‐Glucuron und L‐Guluronsäure mit 2proz. methanolischer Salzsäure entstehenden Glycosidgemische wurden nach der Silylierung gas‐chromatographisch analysiert und die prozentuale Verteilung der auftretenden Pike nach Erreichen des Gleichgewichtes bestimmt. Anhand der gefundenen, auf meso‐Erythrit als internen Standard bezogenen Retentionszeiten wird die Trennbarkeit der Uronsäuren diskutiert.
Synthèses stéréosélectives de deux trioxydes C18H30O3 stéréo‐isomères, d'ambréinolide et de sclaréol‐lactone à partir de dérivés du (+)‐manool
Authors: Demole Edouard , Wuest Hans
Published: December 2004

Ambreinolide, sclareol‐lactone and a pair of new trioxides C18H30O3 have been synthesized from suitable derivatives of (+)‐manool through stereoselective reactions.
Synthese von 7α‐Methyl‐3‐oxo‐Δ4,9,11‐19‐norandrostatrienen. Über Steroide, 211. Mitteilung
Authors: Wieland P. , Anner G.
Published: December 2004

The easy conversion of 3‐oxo‐Δ5(10),9(11)‐19‐norsteroids into 3‐oxo‐Δ4,9,11‐19‐norsteroids by subsequent treatment with a peracid, aluminium oxide, and boron trifluoride is described.
De la chimie des ptérines. 20e communication [1]. Obtention et comportement chimique de diphényl‐6,7‐tétrahydro‐5,6,7,8‐ptérines substituées ou non
Authors: Viscontini M. , Okada T.
Published: December 2004

Les diphényl‐6, 7‐, méthyl‐5‐diphényl‐6, 7‐ et méthyl‐8‐diphényl‐6, 7‐tétrahydro‐5,6,7,8‐ptérines ont été obtenues par reduction au NaBH4 des ptérines ou dihydroptérines correspondantes. Alors que la première et la troisième sont facilement réoxydées en dihydro‐7, 8‐ptérines, la méthyl‐5‐diphényl‐6, 7‐tétrahydroptérine, traitée par O2 ou par H2O2, fixe un atome d'oxygène pour donner la N(2′)‐déhydro‐hydroxy‐4a‐méthyl‐5‐diphényl‐6, 7‐tétrahydroptérine, stable. Tous ces corps ont été caractérisés par analyse élémentaire et par leurs spectres UV., de RMN. et de masse.
Organische Phosphorverbindungen XXIX. Eine neue Methode zur Darstellung von dialkylaminomethylsubstituierten Phosphonig‐ und Phosphinsäuren der allgemeinen Formel R2NCH2PH(O)OH und (R2NCH2)2P(O)OH [1]
Authors: Maier Ludwig
Published: December 2004

A new method for the preparation of dialkylaminomethyl‐phosphonous and‐phosphinic acids, R2NCH2P(O)H(OH) and (R2NCH2)2P(O)OH, is described. This involves reaction of hypophosphorous acid with hydroxymethyl‐dialkyl‐amines or a mixture of formaldehyde and a secondary amine.

equation image

and

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The crystalline acids form monohydrates which are stable up to the melting points of the acids. The IR. and 31P‐NMR. spectra are reported.
Zur massenspektrometrischen Eliminierung von Neutralpartikeln aus Molekel‐ und Fragment‐Ionen
Authors: Bruderer H. , Richter W. , Vetter W.
Published: December 2004

The possibility of elimination reactions without participation of the positive charge and/or electron deficient centers, in particular the loss of RCOOH, was investigated for molecular and fragment ions. Such processes, which could be referred to as quasithermal or quasi‐photochemical reactions, were found to be absent or insignificant.
Die Glykoside der Wurzeln von Kanahia laniflora (FORSSK.) R. BR. 1. Mitteilung: Isolierungen. Glykoside und Aglykone, 299. Mitteilung
Authors: Kapur B. M. , Allgeier H. , Reichstein T.
Published: December 2004

The roots of Kanahia laniflora (FORSSK.) R. BR. contain, in addition to small quantities of cardenolides, a large amount of ester glycosides which are difficulty separable from one another. However, two of these ester glycosides were obtained in a nearly pure form. The crude mixture of ester glycosides, after mild acidic hydrolysis, gave a mixture of acyl‐genins and three sugars: D‐oleandrose, D‐digitoxose and D‐canarose, all of which were obtained in crystalline form. Acetic acid, benzoic acid and another unidentified acid were obtained on alkaline hydrolysis of the mixture of acyl‐genins along with 17‐isolineolon, lineolon, deacetylmetaplexigenin and a small amount of sarcostin‐ketone. Besides these known genins, three probably new genins (α, τ, λ) were obtained in small, but crystalline amounts.
Die Cardenolide von Acokanthera oppositifolia (LAM.) CODD. 3. Mitteilung . Isolierung weitere Cardenolide und teilweise Strukturaufklärung. Glykoside und Aglykone, 301. Mitt.
Authors: Hauschild‐rogat P. , Weiss E. K. , Reichstein T.
Published: December 2004

The presence of 19 cardenolides in the extracts from the seeds of Acokanthear oppositifolia (Lam.) CODD could be traced by means of paper chromatography. Thirteen of these cardenolides could be isolated in crystalline form, acovenoside A (= 2) being by far the major component. Of the other 12 crystalline substances, 5 could be identified with known cardenolides: 2′ = acofrioside L, 3 = acolongifloroside H, 14 = acovenoside C, 15 = acolongifloroside K, 16 = ouabain. The substances 1′, 1″, 4, 6, 7, 8 and 13 are very probably new compounds. Four of these were given trivial names and the following structures were proposed: 1″ = oppovenoside, probably 10; 4 = oppofrioside (5); 6 = acotaloside (6); 13 = opposide, probably 12, cf. following publication [21]. Furthermore, the structure 8 has been proposed for acolongifloroside H.
Pyridinderivate als Komplexbildner VIII Die Herstellung je eines neuen vier‐ und sechszähnigen Liganden
Authors: Anderegg G. , Wenk F.
Published: December 2004

The synthesis of the new complexing agents tris‐(2‐pyridylmethyl)‐amine and N,N,N′,N′‐tetrakis‐(2‐pyridylmethyl)‐ethylenediamine is described, and their protonation constants are given.
3‐O‐Methl‐6‐desoxy‐L‐talose, Synthese und Identifizierung mit L‐Acovenose. Desoxyzucker, 43. Mitteilung
Authors: Kapur B. M. , Allgeier H.
Published: December 2004

3‐O‐methly‐6‐deoxy‐L‐talose has been synthesized starting from 1, 2–5, 6‐di‐O‐isopropylidene‐α‐D‐allose (1). Methylation, selective acidic hydrolysis, sodium periodate oxidation and GRIGNARD reaction with CH3MgBr gave a mixture of the 1, 2‐isopropylidene derivatives of 3‐O‐methyl‐6‐deoxy‐D‐allose and 3‐O‐methyl‐6‐deoxy‐D‐allose (7) and 3‐O‐methyl‐6‐deoxy‐L‐talose (8) (L‐acovenose) could be obtained. Oxidation of the latter gave the corresponding crystalline lactone, which could be indentified with a sample obtained from natural L‐acovenose.
Die Pregnanderivate der Samen von Dregea abyssinica (HOCHST.) K. Schum. (Asclepiadaceae). II. Strukturbestimmungen Glykoside und Aglykone, 305. Mitteilung
Authors: Bhatnagar Ajay S. , Stöcklin W. , Reichstein T.
Published: December 2004

The total or partial structure determinations of some new components from Dregea abyssinica are reported. The four drebyssogenins (F, G, J and H) are esters of the drevogenins P (7) and D(9) and have the following structures: Drebyssogenin F (5) = 11‐O‐acetyl‐12‐O‐(α‐hydroxyisovaleryl)‐drevogenin P, drebyssogenin G (14) = 11‐O‐acetyl‐12‐O‐isovaleryl‐drevogenin D, drebyssogenin J (15) = 11, 12‐di‐O‐acetyl‐drevogenin D. Drebyssogenin K is a mixture of K1 (16) and K2 (17), the mono‐O‐tiglyl and mono‐O‐isovaleryl derivatives of drevogenin D respectively, with as yet undetermined position of the acyl residues. The drebyssosides 1, 2 and 3 are glycosides of trisaccharides. Drebyssoside 1 (2) is pachybiosyl‐cymarosyl‐drevogenin A, drebyssoside 2 (3) asclepobiosyl‐cymarosyl‐drevogenin A and drebyssoside 3 (6) pachybiosyl‐cymarosyl‐drebyssogenin F. Drebyssoside 4 is a mixture of at least two components and contains the same aglycones and the same sugar units as the drebyssosides 1 and 3, but is different from them. The full structure of the two sugars (drebyssobiose (25) and sugar T (24)) has not been determined; it is only shown that both are disaccharides which contain 3‐O‐methyl‐6‐deoxy‐allose linked to a 2‐deoxyhexose.
Isolierung, Aminosäurezusammensetzung und tryptischer Abbau von Thyrocalcitonin aus Schweineschilddrüsen
Authors: Franz J. , Rosenthaler J. , Zehnder K. , Doepfner W. , Huguenin R. , Guttmann St.
Published: December 2004

Hog thyrocalcitonin has been isolated in the form of an homogeneous peptide. After digestion with trypsin three fragments have been separated by paper electrophoresis. the amino acid composition of intact thyrocalcitonin and of the three tryptic fragments is given in a table.
Über die Synthese von 1,4‐Benzoxazepinen und ihre Umlagerung in Isochinoline
Authors: Schenker K.
Published: December 2004

The syntheses of 3‐phenyl‐5‐oxo‐4, 5‐dihydro‐1,4‐benzoxazepine (2) and ‐3‐phenyl‐5‐ethoxy‐1,4‐benzoxazepine (14) are described. 2 rearranges under the influence of sodamide into the isoquinoline derivatives 4, 5 and 6 respectively; 14 is converted quantitatively into 1‐ethoxy‐3‐phenyl‐4‐hydroxy‐isoquinoline (16) in boiling methanol, even in the absence of a strong base. Possible reaction mechanisms are discussed.
Notiz über die Synthese von Iso‐, Noriso‐ und Desäthyl‐tuboflavin
Authors: Rosenkranz H. J. , Schmid H.
Published: December 2004

Treatment of 4,5 ‐dihydrocanthin‐6‐one (V) (prepared from synthetic canthinone (IV)) with ethyl or methyl magnesium iodide and methanolic hydrochloric acid yielded the ethyl or methyl compounds VI and IX. Oxidation of the latter compounds with selenium dioxide in dimethylformamide gave rise to the Pleiocarpa alkaloids isotuboflavine (II) and norisotuboflavine (III) in low yields. Deethyltuboflavine (VIII) was isolated as a byproduct from further oxidation of norisotuboflavine.
Über die Struktur von Imidazolin‐ und Imidazolidin‐Derivaten aus 2‐Amino‐2‐desoxy‐hexosen
Authors: Fritz H. , Morel Ch. J. , Wacker O.
Published: December 2004

In earlier publications [1] [2] [3] [4] a pyranoid structure has been proposed for the sugar moiety of imidazoline and imidazolidine derivatives from D‐glucosamine. But by NMR.‐spectra and periodate oxidation the sugar moiety of these compounds and of similar derivatives from other 2‐amino‐2‐deoxy‐sugars is now shown to be of furanoid structure.
Synthesen von Indolen mit (2‐Aminoäthyl)‐, (2‐Aminopropyl)‐oder Alkanolamin‐Seitenketten am Sechsring. 5. Mitt. über synthetische Indol‐Verbindungen [1]
Authors: Troxler F. , Harnisch A. , Bormann G. , Seemann F. , Szabo L.
Published: December 2004

4‐, 5‐, 6‐ and 7‐cyanoindoles are converted in excellent yields into the corresponding formylindoles by sodium hypophosphite/nickel according to the method of BACKEBERG and STASKUN. Condensation of these formylindoles with nitromethane or nitroethane affords the related nitrovinyl‐indoles, which are reduced to the aminoalkyl‐indoles quoted in the title by means of lithium aluminium hydride.

On the other hand, 5‐chloroacetyl‐indole is aminated by reaction with various secondary amines, and the aminoketones formed are reduced to the corresponding 5‐(2‐amino‐1‐hydroxy‐alkyl)‐indoles. Condensation of 1‐acetyl‐7‐hydroxy‐indoline with chloroacetyl chloride according to FRIEDEL‐CRAFTS yields the 1‐acetyl‐4‐chloroacetyl‐7‐hydroxy‐indoline, which is transformed into indoline derivatives carrying a 2‐amino‐1‐hydroxyethyl side‐chain in position 4.
Kinetische Untersuchungen über Substitutionsreaktionen an Metallkomplexen. 7. Mitteilung [1]. Kinetik und Mechanismus der Reaktion von Methoxyorganylcarbenpentacarbonyl‐chrom‐Verbindungen mit tertiären Phosphinen
Authors: Werner H. , Rascher H.
Published: December 2004

The kinetics of the reactions of methoxyorganylcarbenechromium complexes Cr(CO)5C(OCH3)R′ (R′ = CH3, C6H5) with tertiary phosphines PR3 have been studied by means of spectrophotometric methods. The reaction products of general composition cis‐Cr(CO)4(PR3)C(OCH3)R′, Cr(CO)5PR3 and trans‐Cr(CO)4(PR3)2 are formed by cleavage of both the Cr‐CO and the Cr‐C(carbene) bonds. The two‐term rate law indicates two parallel, dissociative and associative, mechanisms. The kinetic data will be discussed in connection with the concept of labilising and non‐labilising ligands.
Substitution der 6‐Aminopenicillansäure am Kohlenstoffatom 6
Authors: Reiner R. , Zeller P.
Published: December 2004

The hydroxyalkylation of the penicillin nucleus at C‐6 with benzaldehyde and formaldehyde is reported. 6‐aminopenicillanic acid (6‐APA) (2) was used as starting material. Protection of the functional groups and activation of the C‐6 position were effected by converting 6‐APA successively into the Schiff base 13, the methyl ester 14 and the copper complex 15. The latter gave with benzaldehyde the C‐6 monosubstituted complex 17, and with formaldehyde the disubstituted complex 18. The direct α‐hydroxybenzylation of 6‐APA at C‐6 was also carried out with an excess of benzaldehyde at pH 7,5 leading to the SCHIFF base 19. Mild hydrolysis of 19 gave 6‐amino‐6‐(α‐hydroxybenzyl)‐penicillanic acid (21). Phenylacetylation of the latter yielded the penicillin G analogue 22. Direct reaction of 6‐APA with formaldehyde took place only in the presence of salicylaldehyde, giving the oxazolidine 24, from which the amino acid 25 could not be obtained. The new compounds showed only weak antibacterial activity as compared with penicillin G.
Über die Entstehung von α‐Keto‐carbonium‐Ionen bei der säurekatalysierten Hydrolyse von Diazoketonen. (Vorläufige Mitteilung)
Authors: Dahn H. , Gold H. , Ballenegger M. , Lenior J. , Diderich G. , Malherbe R.
Published: December 2004

Secondary deactivated aliphatic diazo compounds (diazo‐ketones RCOCN2R′; diazo‐esters ROOCCN2R′; 1, 1, 1‐trifluoro‐2‐diazopropane) are hydrolysed by the ASE2 mechanism comprising rate determining protonation of the substrate, followed by decomposition. Product analysis shows that the decomposition of the secondary diazonium ions is monomolecular, without intervention of a nucleophile.

The corresponding primary diazo compounds (RCOCHN2, ROOCCHN2 and CF3CHN2) are hydrolysed by the A‐2 mechanism comprising preequilibrium protonation; the primary diazonium ion reacts with a nucleophile in a bimolecular displacement step. The only exception observed is found in p‐nitrophenyl‐diazomethane, which follows ASE2 mechanism.

The observations are discussed in terms of the stability of the corresponding secondary resp. primary α‐keto‐carbonium ions.
Synthese der Purpurin‐8‐carbonsäure; Beitrag zum Boletol‐Problem Vorläufige Mitteilung
Authors: Bräm A. , Eugster C. H.
Published: December 2004

Eine neue und in bezug auf die Stellung der Substituenten eindeutige Synthese von Methoxybenzanthronen wird beschrieben. Oxydativer Abbau an 1,8,10,11‐Tetramethoxybenzanthron führte zu 5,7,8‐Trihydroxy‐anthrachinon‐1‐carbonsäure; an 1,8,11‐Trimethoxyhenzanthron zu 5,8‐Dihydroxyanthrachinon‐1‐carbonsäure. 5,7,8‐Trihydroxy‐anthrachinon‐1‐carbonsäure ist weder mit «Boletol» noch mit «Isoboletol» von KÖGL & DEIJS identisch.

Erneute Isolierung der mit Oxydasen blau werdenden Farbstoffe aus Boletus satanas, B. Iuridus und B. calopus gab kein «Boletol», sondern in Übereinstimmung mit den Ergebnissen anderer Autoren. Variegatsäure (Luridussäure) und weitere Verbindungen.

Boletol ist vorderhand als Naturprodukt zu streichen.
De la chimie des ptérines 27e communication, préliminaire. [1] Sur l'éliminetion du reste N(5)‐méthyle chez les méthyl‐5‐tétrahydro‐5,6,7,8‐ptérines
Authors: Viscontini M. , Okada T.
Published: December 2004

En milieu acide la méthyl‐5‐diphényl‐6, 7‐dihydro‐5, 6‐ptérine perd rapidement son reste méthyle et un H pour être transforméee en diphényl‐6, 7‐ptérine. Il semble qu'un des produits intermédiaires de la transformation soit la méthyl‐5‐diphényl‐6, 7‐dihydro‐5, 8‐ptérine. On suppose qu'à partir de cette ptérine il se forme un radical‐cation perdant spontanément un proton en N(8) et le radical méthyle, phénomène qui pourrait bien être lié à la transéthylation biologique catalysée par les méthyl‐5‐ptérines hydrogénées.
Neue Antipodenpaare zur optischen Spaltung recemischer Basen
Authors: Felder E. , Pitrè D. , Boveri S.
Published: December 2004

As new reagents for optical resolution of racemic bases the enantiomorphs of N‐(1‐phenyl‐ethyl)‐succinamic acid (I) and N‐(1‐phenyl‐ethyl)‐phthalamic acid (II) have been prepared. Optical resolution with I of (1‐phenyl‐ethyl)‐amine, 2‐amino‐butane‐1‐ol, threo‐1‐(4‐nitrophenyl)‐2‐amino‐propane‐1, 3‐diol and with II of 1‐phenyl‐2‐amino‐propane is described.
Long‐range interaction between 1s and 2s or 2p hydrogen atoms
Authors: Kołos W.
Published: December 2004

Long‐range interaction energy between two hydrogen atoms has been computed in the second order of the perturbation theory. All states of the system arising when one of the atoms is in the 1s and the other in the 2s or 2p state have been considered. The energy represented by a series expansion in inverse powers of the internuclear distance, R, has been computed up to the terms in R−8. The results are believed to give reliable interaction energies for R > 15 a.u. Accurate interaction energy for two ground‐state hydrogen atoms has also been obtained up to the terms in R−10. Results for the B′ 1∑ state are employed to discuss the experimental ground‐state dissociation energy of H2, D2, and HD. For H2 all values of the dissociation energy obtained from various experimental absorption limits, by using the computed potential energy curve to separate off the effect of rotation, are shown to be satisfactorily consistent. The resulting total energy of H2 is, however, higher than the most accurate theoretical value.
Geometric approximation for molecular polarizabiities
Authors: Howat G. , Trsic M. , Goscinski O.
Published: December 2004

Molecular polarizabilities calculated with the geometric approximation are shown to be independent of the type of perturbation theory used. Agreement with finite field calculations, including anisotropies, is obtained for small molecules. A modified procedure for including sigma and pi contributions in a differentiated way is developed within the CNDO scheme. Applications to planar conjugated systems are displayed.
Etude Quantique du Pouvoir Rotatoire Naturel et de la Biréfringence Gyrotropique dans un Cristal
Authors: Duprez‐Quesnoit C.
Published: December 2004

A quantum calculation of the optical activity and gyrotropic birefringence is used in a molecular crystal to deduce symmetry properties. A study of the variation of the components of these tensors, when a change of origin occurs, is used to account for the formula for the electric excitation proposed by Landau and Lifchitz. It is shown that the results obtained are valid in the case of crystals with nonlocalized electrons.
Using group (or Loge) functions to explore the transferability of chemical bonds
Authors: Sanchez M. , Daudel R. , Dacre P. D. , McWeeny R. , Kwun S. , Valdemoro C.
Published: December 2004

The transferability of bonds in a set of small molecules has been explored. The molecular wave‐functions have been calculated from the group (or loge) function method, via a construction based on Gaussian functions. The transferability is very good and the effect of lone pairs on adjacent bonds has been analysed. Furthermore, a very simple procedure has been proposed to estimate the frontiers of the bonds.
PCILO Calculations on charge transfer complexes
Authors: Lochmann R. , Hofmann H.‐J.
Published: December 2004

The equilibrium distances of the complex components and the stabilization energies were calculated for the molecular complexes ethylene–fluorine, ethylene–chlorine, tetracyanoethylene–benzene, tetracyanoethylene–durene, and quinone–hydroquinone using the PCILO method. The results are compared with the experimental values and the theoretical predictions of the CNDO/2 method.
Effect of semi‐empirical parameters on the simple random‐phase approximation calculations of conjugated hydrocarbons
Authors: Niyogi B. Guha , Mukherjee D. C. , Sannigrahi A. B.
Published: December 2004

Singlet‐singlet transition energies, oscillator strengths, triplet energy levels, and the ground state correlation energy of a number of conjugated hydrocarbons have been calculated by the simple random‐phase approximation (RPA) within the framework of the Pariser‐Parr‐Pople (PPP) model. The effect of semi‐empirical parameters in such calculations has been examined in detail. A set of parameters has been deduced from these parametric studies which is found to yield results for the singlet spectra of the molecules in excellent agreement with experiment. It is, however, not possible to treat the triplet states using these same parameters, since they produce triplet instabilities in all the molecules. The triplet instability problem associated with semi‐empirical RPA calculations has been discussed in detail.