bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthese von substituierten γ‐Ketosäuren durch alkalische Ringöffnung von 1,1‐disubstituierten Cyclopentandionen‐(2,5)
Authors: Schick H. , Schwarz S. , Eberhardt U. 
Published: December 2004

Abstract1,1‐disubstituierte Cyclopentandione‐(2,5) werden durch Natriumhydroxid in Wasser leicht und vollständig in substituierte γ‐Ketosäuren überführt.Der glatte Verlauf dieser Reaktion ist bemerkenswert, da sich 1‐monosubstituierte Cyclopentandione‐(2,5) auch unter drastischen Reaktionsbedingungen nicht hydrolytisch öffnen lassen.
Struktur und Reaktivität heterosubstituierter Nitrile. XVII [1]. Kinetik und Mechanismus der Phenol‐Addition an Arylcyanate in Gegenwart tertiärer Amine
Authors: El‐Negoumy Sabry , Bacaloglu Radu , Ostrogovich George , Martin Dieter 
Published: December 2004

AbstractDie Geschwindigkeit der Phenol‐Addition an Arylcyanate zu Kohlensäurediarylester‐imiden wurde in Gegenwart tertiärer Amine IR‐spektroskopisch verfolgt. Die Geschwindigkeitskonstanten 1. Ordnung im bezug auf Arylcyanat korrelieren linear mit dem Produkt [ArOH] [ArO‐ ∥ R3NH+]. Die daraus erhaltenen Geschwindigkeitskonstanten 3. Ordnung lassen sich als Funktion von (σ + σ−) der Phenole, durch σ0 der Arylcyanate und die Acidität der Trialkylammoniumsalze beschreiben. Aus den Befunden wird auf einen Übergangszustand geschlossen, der durch nucleophilen Angriff eines Phenolat‐Trialkylammonium‐Ionenpaares an ein Arylcyanat‐Phenol‐Assoziat gebildet wird.
Heterocyclic quinones. XVI. The Reaction of acid Amides with 2,3‐ Dichloro‐1,4‐naphthoquinone, a novel route to naphth[2,3‐d]oxazole‐4,9‐diones
Authors: Hammam Ahmed S. , Osman Abdel‐Magid 
Published: December 2004

AbstractHeating acid amides 2 with 2,3‐dichloro‐1,4‐naphthoquinone 1 in solvents like glycerol or ethylene glycol gave readily naphth [2,3‐d] oxazole‐4,9‐diones 4. The reaction was enhanced by addition of catalytic amounts of sodium hydrogencarbonate, but failed to proceed at all when attempted in low boiling polar or nonpolar solvents. 2‐Amido‐3‐chloro‐1,4‐naphthoquinones 3 were produced as intermediates in these reactions.
Zur Konstitution der Reaktionsprodukte aus Phenacylthioglykolsäure und Benzylmercaptan sowie aus Phenacylbenzylsulfid und Thioglykolsäure
Authors: Brink M. , Schjånberg E. 
Published: December 2004

AbstractPhenacylbenzylsulfid ergibt mit Thioglykolsäure ausschließlich das erwartete Dithioketal C6H5C(SCH2COOH)2CH2SCH2C6H5 (5), während Phenacylthioglykolsäure mit Benzylmercaptan nicht nur das erwartete Dithioketal C6H5C(SCH2C6H5)2CH2SCH2COOH (6) sondern auch das Dithioacetal C6H5CH(SCH2C6H5)CH (SCH2C6H5)2 (4) ergibt. Die Reaktionen wurden in salzsaurem Medium ausgeführt. Die Reaktionsmechanismen wurden auf Grund von präparativen und NMR‐spektroskopischen Untersuchungen diskutiert.
1H‐NMR‐spektroskopische Analyse von 2‐Dimethylamino‐[1,3,2]dioxarsolan und ‐dithiarsolan
Authors: Adler Oswald , Kober Friedhelm 
Published: December 2004

AbstractDie 1H‐NMR‐Spektren der Methylenprotonen in den Arsolanen (CH2)2X2As‐N(CH3)2 (X = O, S) bilden ein AA′BB′‐Spinsystem, das sich bei Zusatz von Dimethylamin zum A4‐System vereinfacht. Die Vereinfachung beweist einen schnellen Austausch der N(CH3)2‐Gruppe. Diese Annahme wird durch Isotopenmarkierung mit 15N‐markiertem Dimethylamin bestätigt.
Kristallin‐flüssige 3,6‐Diphenyl‐1,2,4‐triazine
Authors: Zaschke H. , Nitsche K. , Schubert H. 
Published: December 2004

AbstractDie Synthesen mono‐ und disubstituierter 3,6‐Diphenyl‐1,2,4‐triazine werden beschrieben und die kristallin‐flüssigen Eigenschaften dieser Verbindungen diskutiert. Das Schmelzverhalten homologer Reihen wird in Abbildungen graphisch dargestellt.
Katalytische Spaltung substituierter 1,3‐Dioxane
Authors: Červený Libor , Marhoul Antonín , Růžička Vlastimil 
Published: December 2004

AbstractEs wurde die katalytische Spaltung von 4‐Phenyl‐1,3‐dioxan und 4‐Methyl‐4‐phenyl‐1,3‐dioxan an Palladiumkatalysatoren und an einem CuO/Cr2O3/BaCrO4‐Kontakt untersucht. Hydrogenolytisch können aus den besprochenen 1,3‐Dioxanen am CuO/Cr2O3/ BaCrO4‐Kontakt mit hoher Ausbeute 3‐Phenyl‐1‐propanol und 3‐Phenyl‐1‐butanol hergestellt werden. Diese primären Alkohole können auch ohne Druckanwendung an Palladiumkatalysatoren in Wasserstoffatmosphäre hergestellt werden.Durch die Spaltung von 4‐Phenyl‐1,3‐dioxan in inerter Atmosphäre entsteht mit hoher Selektivität Propiophenon. Die Nebenprodukte der Reaktionen wurden identifiziert und ein Reaktionsschema der katalytischen Spaltung aufgestellt.
Über definierte Polyoxyäthylenderivate. V. [1] Stickstoffhaltige Polyoxyäthylene
Authors: Gerhardt Werner , Kucharski Stanislaw 
Published: December 2004

AbstractSynthese und Eigenschaften langkettiger α‐Hydro‐ω‐alkylamino‐polyoxy‐äthylene, deren Methyläther sowie α‐Hydro‐ω‐N‐dodecylacetamido‐polyoxyäthylene werden beschrieben. Spezielle Tensideigenschaften wie Löslichkeit, Oberflächenaktivität und Micellbildung werden diskutiert.
Über Umsetzungen von Saccharose mit 1‐ (n‐Alkoxy)‐äthylisocyananten
Authors: Lesiak T. , Iwaszkiewicz‐Nowak J. 
Published: December 2004

AbstractEs wird über ein Verfahren zur Darstellung von neuen, langkettigen N‐[1‐(n‐Alkoxy)‐äthyl]‐carbaminsäure‐monoestern der Saccharose berichtet. Reaktionsbedingungen werden ermittelt und Eigenschaften von Saccharose‐N‐[1‐(n‐hexoxy)‐äthyl]‐ 1, N‐[1‐(n‐octoxy)‐äthyl]‐ 2 und N‐[1‐(n‐decoxy)‐äthyl]‐carbaminsäure‐monoester 3 (Isomerengemische) beschrieben. Oberflächenspannungen wäßriger Lösungen der genannten Verbindungen in Abhängigkeit von der Konzentration werden mit jenen von Natriumdodecylsulfat verglichen.
Über den Einfluß einiger Versuchsparameter auf die homogen durch WCl6–EtAlCl2 katalysierte Olefinmetathese von Penten‐(2)
Authors: Beger Jörg , Sass Regina , Zimmermann Gerhard 
Published: December 2004

AbstractAm Beispiel der Metathesereaktion eines cis‐trans‐Gemisches von Penten‐(2) mit dem in situ aus Wolfram‐(VI)‐chlorid und Äthylaluminiumdichlorid (EtAlCl2) gebildeten und in homogener Flüssigphase vorliegenden Katalysatorsystems wurde der Einfluß verschiedener Lösungsmittel, des Zusatzes von Lewisbasen und verschiedener Molverhältnisse von Komponenten der Reaktionsansätze untersucht. In einigen Fällen wurde neben der Metathesereaktion eine Alkylierung aromatischer Lösungsmittel beobachtet.
Synthesen 3‐substituierter 7,8‐Dimethyl‐1,5‐dihydro‐2,4‐benzdithiepine
Authors: Gross Hans , Keitel Iris , Costisella Burkhard 
Published: December 2004

Synthesis of 3‐Substituted 7,8‐Dimethyl‐1,5‐dihydro‐2,4‐benzdithiepines7,8‐Dimethyl‐1,5‐dihydro‐2,4‐benzdithiepines substituted in 3‐position are available from the dithiol1and aldehydes or acetales. By chlorination of the dithiepin6the 3‐chloro‐dithiepin3is formed, which was not available in pure state, but can be transformed in situ with N‐ or C‐nucleophiles into the respective2‐derivatives. By oxidation of6using chloramin T and subsequent reaction with methanol the 3‐methoxy derivative4is formed via the S‐tosyliminocompound5.
Epaminierungen. II. Herstellung von Aziridinen aus Olefinen und N‐Halogenaminen
Authors: Schmitz Ernst , Bicker Uwe , Schramm Siegfried , Dietz Klaus‐Peter 
Published: December 2004

Epaminations. II. Synthesis of Aziridines from Olefins and N‐HaloaminesChloramine, dichloramine as well as the N‐chloro‐ and N‐bromo‐derivatives of primary aliphatic amines react with olefins to give aziridines. Yields up to 75% are obtained by the reaction of N.N‐dibromamines with styrene‐type olefins. The reaction is shown to proceed stereo‐unspecifically by a chain‐mechanism with the radical RN·Br as the chain carrier.
6‐Substituierte 2,4‐Diphenyl‐1,3,4‐oxadiazin‐5‐one
Authors: Westphal Günter , Müller Thomas 
Published: December 2004

6‐Substituted 2,4‐diphenyl‐1,3,4‐oxadiazin‐5‐onesBy reaction of dichloro acetylchloride and β‐N‐phenyl benzhydrazide 6‐chloro‐1,3,4‐oxadiazin‐5‐one 2 is accessible which reacts with potassium phthalimide and potassium succinimide, respectively, to from 6‐phthalimido‐ and 6‐succinimido 2,4‐diphenyl‐1,3,4‐oxidiazinon (3 and 4), respectively. The phthalimido substituent can be substituted by benzylamine or hydrazine.
1H‐NMR‐Untersuchungen zur innermolekularen Beweglichkeit substituierter Acrylsäureester
Authors: Knippel E. , Knippel M. , Michalik M. , Kelling H. , Kristen H. 
Published: December 2004

1H‐N.M.R. Spectroscopic Investigations on Innermolecular Mobility of Substituted AcrylatesThe barriers of rotation around the CC‐bond of, ethyl 3‐arylamino‐2‐nitro‐acrylates 1 and ethyl 3‐arylamino‐2‐cyano‐acrylates 2 have been determined by dynamic n.m.r. spectroscopy. From coalescence phenomena the free activation enthalpies ΔG≠ of rotational processes are determined and discussed with respect to substituent effects.
Acylketen‐S,S‐ und Acylketen‐S,N‐acetale als Bausteine für Heterocyclen: Pyrazole und Isoxazole
Authors: Rudorf W.‐D. , Augustin M. 
Published: December 2004

Acylketene S,S‐ and Acylketene S,N‐Acetals as Buildingsets for Heterocycles: Pyrazoles and IsoxazolesAcylketene S,S‐acetals 1 react with hydrazines, semicarbazide, and benzhydrazide to yield tautomeric or isomeric pyrazoles 8 and 10, respectively. On the other hand cyclisation to the aminopyrazoles 9 is possible. The pyrazoles 8 are also obtained by reaction of the dithioesters 2 with hydrazine in the presence of mercury oxide. 3(5)‐Aminopyrazoles 17 can be synthesized in three different ways: from the acylketene S,N‐acetals 3, from the thioamides 4 or from the acylketene N,N‐acetals 5 and hydrazine. The reaction of 3 with phenylhydrazine and p‐nitrophenylhydrazine leads to the 5‐aminopyrazoles 20, but 8e and 9d are formed by the elimination of 1 mol arylamine. The dependence of the reaction way on the kind of the used hydrazine is discussed. The reaction of acylketene S,S‐acetals 1 and S,N‐acetals 3 with hydroxylamine affords isoxazoles 21 and 22.
Synthese und Reaktionen von 1,3‐Azaphosphorinan‐2‐thionen
Authors: Oehme H. , Leissring E. , Thamm R. 
Published: December 2004

Synthesis and Reactions of 1,3‐Azaphosphorinane‐2‐thionesAminopropylphosphines, RP(H)(CH2)3NH2, react with carbon disulfide to give 1,3‐azaphosphorinane‐2‐thiones. In presence of strong bases the title compounds are converted by alkyl halides into 2‐alkylthio‐3, 4, 5, 6‐tetrahydro‐1, 3‐azaphosphorines whereas in absence of bases quaternization at the phosphorus atom occurs to give 2‐thiono ‐1,3‐azaphosphorinanium salts. The structures of the compounds prepared are elucidated by IR. 1H‐n.m.r. and mass spectra.
Vinyloge Acylverbindungen. XVIII [1]. Einfluß sterischer Faktoren auf das Reaktionsverhalten vinyloger Carbonamidiumsalze
Authors: Fischer Gerhard W. 
Published: December 2004

Vinylogous Acyl Compounds. XVIII. Influence of Steric Factors on the Reaction Behaviour of Vinylogous Carbonamidium SaltsDepending on the size of their N‐alkyl groups vinylogous carbonamidium salts show a markedly graduated reactivity under suitable conditions. Thus 2‐formyl‐vinyl trimethylammonium perchlorate 1a is decomposed by sodium hydroxide yielding only trimethylamine and salts of malondialdehyde 2, while the analogous triethylammonium salt 1b additionally undergoes a fragmentation to triethylamine, acetylene and formic acid. The reaction of 4‐(4‐nitrobenzyl)‐pyridine with 1 and the analogous 2‐benzoylvinylammonium salts 3 to the 1,4‐dihydropyridine dye 4 and 5, respectively, is faster by orders of magnitude in the case R′ = CH3 than in the case R′ = C2H5. Contrary to the 1a‐p‐nitrophenylhydrazone 6a which can be transformed into the pyrazole 7 the 1b‐hydrazone 6b withstands such a ring closure. Depending on the reaction conditions and nature of the substituent R the action of aniline on 1 leads either to the monoanils 8 or to the malondialdehyde dianil salt 9. While piperidine reacts with 3a as well as with 3b to give N‐(2‐benzoylvinyl)‐piperidine 10, aniline forms a corresponding vinylogous amide 11 only with 3a. 3b, however, on reaction with aniline · HCl via the intermediate monoanil 12, yields the vinylogous amidinium salt 13 which is not obtainable from 3a or 11. Using o‐phenylendiamine this reactivity graduation can be utilized for preparing 2‐aryl‐substituted 1H‐1,5‐benzodiazepinium salts, e.g. 17.
Desaktivierungsverhalten von Arenen und Heteroarenen. XII. Kinetik der Photodimerisierung von Akridiziniumsalzen
Authors: Bendig J. , Geppert B. , Kerysig D. 
Published: December 2004

Deactivation Behaviour of Arenes and Heteroarenes. XII. Kinetics of Photodimerization of Akridizinium SaltsResulting from the photo‐kinetic parameters of the deactivation of the akridizinium ion the photodimerization and ‐monomerization of the dimers obtained are investigated, and the rate constants of partial processes are determined. The values of the quantum yield of the dimerization (c∞) in methanol and the monomerization are 0,23 and 0,49, respectively. The presence of compounds with heavy atoms, electron donors and anions of high polarisibility results in a decrease of the quantum yields. In the case of the dimerization process this effect is more intense than in the case of monomerization. From the comparison of these results with those of fluorescence quenching it can be concluded, that non‐luminescent excimers with a life‐time of about 1 ns are formed intermediately.
Kinetische Modellierung der Essigsäure‐Addition an n‐Alkene
Authors: Keck R. , Prinzler H. 
Published: December 2004

Kinetic Investigation of Acetic Acid Addition to n‐AlkenesAcetic acid addition to n‐alkenes, isomerization of n‐alkenes and carboxylic acid ester dissociation – all catalyzed by protonic acids – were kinetically treated both by the aid of an analogue computer and by the scheme of Rosenbrock. Simple models were developed and analyzed to reach results capable of generalization.A four parameter model yielded at 100°C for the n‐hexenes k‐value proportions kadd./kisom.= 2.23 and kadd.1‐en/kadd.Δ2/Δ3‐en = 3.37.The homologous series of the 1‐alkenes (C4to C18) was studied using a three parameter model. The carboxylic acid addition is almost independent of the length of the carbon chain.The proportion kadd./kdiss.amounts to beetween five and six at 100°C.The description of the carboxylic acid addition to n‐alkenes with internal double bond (C7to C17) takes place on the basis of a six parameter model.According to this model, the addition rate decreases with increasing chain length.In the isomeric series of n‐tridecenes the reaction rate decreases by the migration of the double bound into the midst of the chain. Cis‐alkenes reacted faster than the corresponding trans‐alkenes.
Thiophosphorylation of Alcohols in the Four‐Component System: Ph3P/CCI4/(C2H5O)2P(S)OH resp. (C2H5O)2P(S)SH/(C2H5)3N
Authors: Młotkowska B. , Zwierzak A. 
Published: December 2004

Thiophosphorylierung von Alkoholen im Vier‐Komponenten‐System: Ph3P/CCl4/(C2H5O)2P(S)OH bzw. (C2H5O)2P(S)SH/(C2H5)3NBei der Reaktion in dem Vier‐Komponentensystem (Thio‐ und Dithiophosphorsäure‐O, O‐diethylester 2 bzw. 6 ‐Triphenylphosphin‐Tetrachlorkohlenstoff‐Triethylamin) und Alkoholen entstehen die Thiolester 3/4 bzw. 7/4 als Hauptprodukte. Ein möglicher Mechanismus der nicht eindeutig verlaufenden Thiophosphorylierungsreaktion wird formuliert. Es werden Thiophosphoryloxyphosphonium‐Komplexe als Zwischenprodukte, ihr dynamisches Gleichgewicht und der Zerfall postuliert. Analoge Komplexe, die sich in verwandten Reaktionen als Zwischenprodukte bilden, wurden ebenfalls untersucht.
Untersuchung fester Komplexe von Triphenylmethylsalzen mit Donatoren
Authors: Heublein G. , Schubert G. , Hallpap P. 
Published: December 2004

Investigation of Solid Complexes of Triphenylmethyl Salts with DonorsTriphenylmethyl salts form crystalline complexes, which can be characterized by UV‐VIS reflexion spectroscopy as well as by thermal methods. The stability of the solid complexes is essentially determined by the size of the substituents in the cation (p‐R‐C6H4)3C+ with R = CH3, H, Br and by that of the aromate (benzene, toluene, p‐xylene, mesitylene). In constrat to the behaviour in solution a change of the anion (SbCl6−, FeCl4−) has a strong influence on the stability. Because of the appearance of a charge‐transfer absorption the complexes are described as EDA complexes.
Zur katalytischen Aktivität glasfixierter Übergangsmetall‐komplexe
Authors: Schwetlick Klaus , Unverferth Klaus , Tietz Renate , Pelz Jürgen 
Published: December 2004

The Catalytic Activity of Glass‐fixated Transition‐metal ComplexesThe formation of p‐ethyloxycarbonylphenyl isocyanate from p‐ethyloxycarbonyl‐phenyl azide and carbon monoxide in the presence of supported rhodium complexes, synthesized by reaction of RhCl(CO)(Ph2PCH2CH2Si[OEt]3)2with porous silica glasses, is followed kinetically. The glass‐fixated complexes are catalytically 500–1000 times less active than the homogeneously dissolved one. Their activity decreases with increasing metal loading of the glasses. The activation energy of the heterogeneous reaction is larger than that of the homogeneous reaction, and the reaction rate is independent of the pellet diameter, the pore volume, the pore diameter, and the specific surface of the glass supports, which speaks against a retardation fo the reaction by pore diffusion.
Infrarotintensitätsmessungen, Dipolmomentbestimmungen und 1H‐NMR‐Untersuchungen an ausgewählten Zweikern‐aromat‐chrom‐tricarbonyl‐Komplexen
Authors: Reinke H. , Oehme G. 
Published: December 2004

Infrared Intensity Measurements, Dipole Moment and 1HNMR Studies on Selected Chromium Tricarbonyl Complexes of Dinuclear ArenesIntegrated intensities of v(CO)vibration bands in a series of mono‐ und di(tricarbonyl‐chromium)‐π‐complexes of substituted and unsubstituted dinuclear arenes of the ArCAr or ArCCAr type have been measured in tetrahydrofurane solution. The bond angles α between the CO groups have been determined by the method of BECK. The values of these angles range from 83° to 90° and do not permit decisions concerning the intramolecular interactions between two tricarbonylchromium groups.On the other hand a band analysis showed that there are two A1 modes in the spectrum of benzylbenzene di(tricarbonyl‐chromium), whose intensity ratio is both temperature and solvent dependent. One can assume preferred conformations in the C(H2)‐arene bond due to the neighbourhood of the tricarbonylchromium groups. In connection with dipole measurements a ratio of conformers could be estimated.1HNMR data showed that there is a hindrance of the free rotation, already present in benzylbenzene(tricarbonyl‐chromium).
Struktur und Isomerisierung der 1,3‐dipolaren Cycloaddukte von Malein‐ und Fumarsäure‐dimethylester an Pyrazolidon‐(3)‐azomethinimine
Authors: Dorn Helmut , Ozegowski Rüdiger , Gründemann Egon 
Published: December 2004

Structures and Isomerisation of the 1,3‐Dipolar Cycloadducts of Dimethyl Maleate and Fumarate to 3‐Pyrazolidone‐azomethiniminesThe 1,3‐dipolar cycloaddition of dimethyl maleate 1b and fumarate 5b to the 3‐pyrazolidone‐azomethinimine 2 is a stereospecific cisoid reaction yielding the perhydropyrazolo[1,2‐a] pyrazoles 3b/4b in the molar ratio of 2:1, and 6b/7b in the molar ratio 1:1. Starting with each of the 4 stereoisomers, epimerization, catalysed by alcoholate, results in all 4 of them 3b, 4b, 6b and 7b with 7b as sterically favoured main product. During the addition reaction no epimerization is occurring. 1H‐ and 13C‐n.m.r. data are discussed.
Die Charakterisierung der strahlungslosen Desaktivierung des ersten Singulett‐Anregungszustandes von N‐Methylacridon mittels Triplett‐sensibilisierter (E) → (Z)‐Photoisomerisierung von (E)‐Stilben
Authors: Bendig Jürgen , Siegmund Manfred 
Published: December 2004

Characterization of the Radiationless Deactivation of the Lowest Excited Singlet State of N‐Methylacridone by Means of the Triplet Sensitized (E) → (Z) Photoisomerization of (E)‐StilbeneThe (E) → (Z) isomerization of (E)‐stilbene photosensitized by N‐methylacridone (A) has been studied under anaerobic conditions at 298 K in dependence on the solvent as well as the concentration of iodoethane as heavy atomquencher. For the experimental conditions the quantum yield of the triplet‐triplet energy transfer 3A* → 3E* is unity and the photoreaction is homogenous.The ISC quantum yield of the sensitizer N‐methylacridone was determined from the initial slopes of the plotted concentration‐time functions in the solvents methanol, N‐methylformamide, acetonitrile, dichloromethane, tetrahydrofuran, benzene and tetrachloromethane, respectively. The comparison of the ISC quantum yields ψisc and the quantum yields of fluorescence ψf indicate that ψf + ψisc = 1 is true for the used solvents; the IC process is negligible.
Untersuchungen an EDA‐Komplexen von Benzylarylethern
Authors: Weschke W. , Timpe H.‐J. , Just G. 
Published: December 2004

Studies on the EDA‐Complexes of BenzylarylethersBenzylarylethers form electron donator‐acceptor complexes with tetracyanoethylene (TCNE) and 2,3‐dichloro‐5,6‐dicyano‐p‐benzoquinone (DDQ). The appearance of two charge‐transfer transitions is characteristic of the EDA‐complexes of TCNE. There is a linear relationship between the transition energies and the σ‐constants of the substituents of the ethers. Ionization potentials of the benzylarylethers could be calculate using the energies of CT bands. Beside the DA complex exists a D2A complex, too. By means of a special method of calculation it is possible to estimate true values of the constants of complex forming and of the extinction coefficients.
Tetrathiafulvalene. IX. Elektrische Leitfähigkeit phenylsubstituierter, benzo‐ und naphthokondensierter Tetrathiafulvalen‐TCNQ‐Komplexe
Authors: Schukat G. , Fanghänel E. 
Published: December 2004

Tetrathiafulvalenes. IX. Electrical Conductivity of Phenylsubstituted, Benzo‐ and Naphthocondensed Tetrathiafulvalene‐TCNQ‐Complexes.Complex formation of phenylsubstituted, benzo‐ and naphthocondensed tetrathiafulvalenes with tetracyanoquinodimethane and iodine is described. The electrical conductivity is high in the complexes, when radical salts of donor and acceptor are formed and the donator has a planar geometry.
Synthese und π‐Elektronenstruktur von 2,5‐Bis‐alkylamino‐terephthalsäurediethylestern
Authors: Ulbricht H. , Löber G. , Kittler L. 
Published: December 2004

Synthesis and π‐Electronic Structure of 2,5‐Bis(alkylamino)‐terephthalic Acid Diethyl Ester2,5‐Dioxocyclohexane‐1,4‐dicarboxylic acid diethyl ester1reacts with primary alkylamines2to 2,5‐bis‐(alkyl‐amino)‐cyclohexa‐1,4‐diene‐1,4‐dicarboxylic acid diethyl ester3. The dehydrogenation of3by means of bromine or chloranil leads to 2,5‐bis(alkylamino) terephthalic acid diethyl ester4. Electronic spectra and quantumchemical calculations according the SCF‐LCI method indicated that the absorption proporties of4in the visible spectral region follow the general pattern of substituted aromatic compounds. A merocyanine‐like electronic structure seems to be less probable.
Zur Rhodium‐katalysierten Carbonylierung aromatischer Nitroverbindungen zu Isocyanaten. II. Untersuchungen zum Reaktionsmechanismus
Authors: Unverferth K. , Höntsch R. , Schwetlick K. 
Published: December 2004

Rhodium Catalyzed Carbonylation of Aromatic Nitro Compounds to Form Arylisocyanates. II. Studies on the Mechanism of the ReactionAromatic nitro compounds are carbonylated to form arylisocyanates in the presence of rhodium carbonyl complexes and metal halides of the groups VB and VIB of the periodic table.The reaction is first order in nitro compound. The desoxygenation of the nitro compound is the rate determining step of the reaction. Substituents in ortho‐position to the nitro group increase the reaction rate. A structure of an isolated intermediate is proposed from analytical and spectroscopical data.