Tetrathiafulvalene. XXIV. Gewinnung von cis- und trans- Isomeren bei Tetrathiafulvalenen (TTF)

Tetrathiafulvalenes. XXIV. Isolation of cis- and trans-Isomers of Tetrathiafulvalenes (TTF) The synthesis of naphthylsubstituted TTF permits in the case of the α-naphthyl-methylsubstituted TTF the isolation of the cis- and trans-isomer by reason of differences in the solubility. The spectroscopical and electrochemical properties of naphthylsubstituted TTF are described.     

Synthese von 3-Amino-1.2-dithioliumsalzen und deren Umwandlung in 2-Nitro-3-amino-thiophene

Synthesis of 3-Amino-1,2-dithiolium Salts and their Conversion to 2-Nitro-3-aminothiophenes 3-Amino-1.2-dithiolium salts 2a–1 are easily available from 3-chloro-1,2-dithiolium salts 1 and secondary amines. A new procedure to prepare 2-nitro-3-aminothiophenes 3 starting from N,N-substituted 3-amino-5-phenyl-1,2-dithiolium salts 2 is described which consists in a nucleophilic exchange of a sulfur atom for the carbon atom of nitromethane. The structure of 3 has been confirmed by reductive cyclization and by spectroscopic methods.     

Synthese und Reaktionen von 1,3-Azaphosphorinan-2-thionen

Synthesis and Reactions of 1,3-Azaphosphorinane-2-thiones Aminopropylphosphines, 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.     

Tetrathiafulvalene. XVIII. Elektronen-Donator-Akzeptor-Komplexe von Tetrathiafulvalenen (TTF) mit Tetracyanochinodimethan (TCNQ)

Tetrathiafulvalenes. XVIII. Charge-Transfer-Complexes of Tetrathiafulvalenes (TTF) with Tetracyanoquinodimethane (TCNQ) TTF form CT-complexes with TCNQ in solvents having small E_T-values, whose association constants are estimated. The energy of the absorption maximum of the CT-complex between octamethylentetrathiafulvalene and TCNQ increases linearly with decreasing E_T-values of the solvents. In chloroform the energy of the absorption maximum of the CT-complexes between TCNQ and tetrathiafulvalenes increases linearly with the oxidation potential of the tetrathiafulvalene.     

Tetrathiafulvalene. XXII [1] Redox- und spektroskopische Eigenschaften von Tetrathiafulvalenen (TTF) und Tetraselenafulvalenen (TSF) sowie deren Mono- und Dikationen

Tetrathiafulvalenes. XXII. Redox- and Spectroscopic Properties of Tetrathiafulvalenes (TTF) and Tetraselenafulvalenes (TSF) and their Mono- and Dications The polarographic oxidation potential of TTF is decreased by alkyl- and increased by aryl-substituents. The oxidation potentials of arylated TTF can be correlated with σ⁺-constants (σ  0,1). TSF are weaker donors than the respective TTF. Alkyl substitution at TTF causes a bathocromic shift and aryl substitution a hypsochromic shift of the longest wavelength absorption band. In the mono- and dications of TTF a bathochromic shift of this absorption band is observed by alkyl- as well as aryl-substituents which is especially pronounced, when the molecule is planar.     

Synthese von 2-Heterocyclidenamino-1,3-diazatrimethincyaninen

Synthesis of 2-Heterocyclidenamino-1, 3-diaza-trimethincyanines The synthesis of 2-[3-methyl-benzthiazol-(1, 3)-inylidene-(2)-amino]- and of substituted 2-[1, 3-dithiolyliden-(2)-amino]-1, 3-diaza-trimethincyanines is described. The heterocyclic imines 1 react with phosgene or thiophosgene to the corresponding ureas 2 and thiureas 3 , respectively. Alkylation of 3 to the 2-alkylmercapto-1, 3-diaza-trimethincyanines 4 and subsequent condensation with imine 1 yields the dyes 5 . The chemical and spectroscopical data of cyanines 5 are described.     

Tetrathiafulvalene. XX. Charge-Transfer,Radikalkonzentration und elektrische Eigenschaften von TTF und TSF-TCNQ-Komplexen

Tetrathiafulvalenes XX. Charge-Transfer, Radical Concentration and Electrical Properties of TTF- and TSF-TCNQ-Complexes For TTF-TCNQ-complexes the spin density increases with a higher degree of CT, estimated from the value of C-N-vibration in TNCQ. The dihydronaphthocondensed cis- and trans-TSF-TCNQ-complexes ( 11, 12 ) show the same high conductivity, whether the complex composition is 2:1 or 1:1.     

Synthese von aliphatischen Aldehyden aus Alkanen und Kohlendioxid: Valeraldehyd aus Butan und CO2 – Machbarkeit und Grenzen

During the last decades, the engineering of chemical processes has focused more and more on energy efficiency and reduction of climate‐changing emissions. Regarding the synthesis of aldehydes, the photocatalytic dehydrogenation of alkanes to olefins, using visible (sun) light, and the subsequent hydroformylation of such olefins with CO₂ seem to be capable to achieve both targets. This work deals mainly with catalyst concepts for both reaction steps. Here, kinetic studies of the photocatalytic alkane dehydrogenation are presented, and the feasibility of hydroformylation using CO₂ is described in a continuous gas phase reaction. The problems that have to be solved befoe the technical application are discussed and an economic and ecological evaluation for both processes is carried out.     

Synthese und Charakterisierung von Epoxidharzen aus Bisphenol A,Cyanursäuure und Epichlorhydrin

Epoxy resins of Bisphenol A, cyanuric acid, and their mixtures were synthetized with epichlorohydrin. The obtained products were characterized by gel permeation chromatography, FT-IR-spectroscopy, ¹H-NMR-, ¹³C-NMR-spectroscopy and DSC-analysis. During the syntheses besides the glycidyl-derivatives of Bisphenol A and cyanuric acid also biuret-derivatives were formed as a result of cracking the isocyanurate-ring. The formed resins of Bisphenol A-cyanuric acid mixtures can be crosslinked by heat without additional curing agents.     

Synthese und Reaktionsverhalten von 2-Aryloxy-s-trithianen

Synthesis and Reactions of 2-Aryloxy-s-trithianes 2-Aryloxy-s-trithianes 4 had been prepared from 1-tosyl-imino-1-S^IV-1,3,5-trithiane and phenolates. – By self-condensation of 4 1,5-bis-(trithianyl)-1,3,5-trithiapentane 5 and triphenyl-orthoformate 7 are formed, accompanied by further products, which had been isolated in pure state and identified unambiguously by H-n.m.r. and mass-spectra. In the presence of acids the 2-aryloxy-s-trithianes 4 react with nucleophilic aromatic compounds such as phenoles, N,N-dimethylaniline, pyrrole, indole, and thiophenes to give the C-trithianylated products. With mercaptanes 2-alkylthio-s-trithianes are formed.     

Tetrathiafulvalene. XVI. Spektroskopische und elektrische Eigenschaften von TTF und TTF-TCNQ-Komplexen

Tetrathiafulvalenes. XVI. Spectroscopic and Electrical Properties of TTF and TTF-TCNQ-Complexes UV-vis-spectra of mono- and dications of the TTF 2 show in comparison to those of TTF 1 and 3 that the aryl substituent in the TTF 2 is more twisted from the TTF-plane than in 1 and 3 . Absorption maxima of mono- and dications from TTF 1 and 3 lie at a significantly greater wavelength than absorption maxima of mono- and dications from TTF 2 , because a better electronic interaction between substituents in the aryl-group and the positively charged dithiolium-ring is possible. TCNQ-complexes of smoother TTF 3 also have a higher electrical conductivity than TCNQ-complexes of 2 .     

Synthese von 2-aminosubstituierten 4,5-Dihydro-1,3-thiazolen

Synthesis of 2-Amino-Substituted 4,5-Dihydro-1,3-thiazoles . The reaction of 2-substituted 4-methallylthiosemicarbazides 1 with carbonyl compounds catalyzed by weak acids gives thiosemicarbazones 2 and 1,2,4-triazolidine-3-thiones 3 . By contrast under strong acidic conditions the reaction occurs by electrophilic cyclisation with participation of the methallyl and thiono groups, and 4,5-dihydro-1,3-thiazoles 5 are formed after neutralisation. The electrophilic cyclisation of N-methallyl substituted thioureas 6 and 1,4-disubstituted thiosemicarbazides 7 is also described.