bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tetrazolverbindungen. 2. (1‐Aryl‐1H‐tetrazol‐5‐yl)‐acetaldehyd‐Derivate aus 1‐Aryl‐5‐(2‐dimethylamino‐vinyl)‐1H‐tetrazolen
Authors: Fischer G. W. 
Published: December 2004

Tetrazole Compounds. 2. 1‐Aryl‐1H‐tetrazole‐5‐acetaldehyde Derivatives from 1‐Aryl‐5‐(2‐dimethylamino‐vinyl)‐1H‐tetrazoles1‐Aryl‐5‐(2‐dialkylamino‐vinyl)‐1H‐tetrazoles 2, easily accessible by the reaction of 3‐chloro‐propeniminium salts 1 with excess sodium azide in refluxing alcohols, represent enamines of the hitherto unknown 1‐aryl‐1H‐tetrazole‐5‐acetaldehydes 3. Attempts to isolate the latter after acid‐catalyzed hydrolysis of 2 were unsuccessful. However, generated in situ, they can be trapped by suitable aldehyde reagents. Thus, starting from 1‐aryl‐5‐(2‐dimethylamino‐vinyl)‐1H‐tetrazoles 4, the 4‐nitrophenylhydrazones 5a‐‐hyphen;i, 2,4‐dinitrophenylhydrazones 5j‐‐hyphen;r, and thiosemicarbazones 6 of the corresponding 1‐aryl‐1H‐tetrazole‐5‐acetaldehydes 3 were obtained. Analogously, acid‐catalyzed hydrolysis of 4 in the presence of 1,2‐dianilinoethane resulted in 1‐aryl‐5‐(1,3‐diphenyl‐2‐imidazolidinylmethyl)‐1H‐tetrazoles 7. ‐‐hyphen; The structure of the aldehyde derivatives 5, 6, and 7 was proved by 1H n.m.r. spectroscopy.
Synthese einiger neuer 3,4‐Diarylsydnone
Authors: Csongar Ch. , Müller I. , Slezak H. , Klebsch H.‐J. , Tomaschewski G. 
Published: December 2004

Synthesis of Some New 3,4‐DiarylsydnonesThe synthesis of some new sydnones 4 is described. Their characteristic absorption maxima, mass spectroscopic fragmentation and CO‐valence vibrations are given. The sydnones 4 are synthezid by nitrosation of C, N‐diarylglycines 3 (from strecker synthesis) and subsequent cyclization with Ac2O. The primarily formed C,N‐diaryl‐α‐aminoacetic acid nitrils (1) are decomposed with conc. HCl yielding glycines (3) in good yields.
Iminoformylierung substituierter Crotonnitrile. III. Zur Stereochemie und innermolekularen Beweglichkeit von 4‐Amino‐1,1‐dicyanbuta‐1,3‐dienen
Authors: Michalik Manfred , Zahn Kerstin , Köckritz Peter , Liebscher Jürgen 
Published: December 2004

Iminoformylation Reaction of Substituted Crotonnitriles. III. Stereochemistry and Intramolecular Mobility of 4‐Amino‐1.1‐dicyano‐buta‐1.3‐dienes1H‐ and 13C‐n.m.r. spectroscopic investigations show the preference of s‐trans configuration and the push‐pull character of the investigated 4‐amino‐1,1‐dicyano‐buta‐1,3‐dienes. Dynamic 1H‐ and 13C‐n.m.r. data for the rotation process about the CN bond are determined. The activation energies are discussed with respect to electronic and steric effects of substituents and to solvents polarity.
Preparation and cyclisation reactions of 3‐Carboxy‐4‐naphthylbut‐3‐enoic Acids
Authors: Guirguis Nadia R. , Awad Boshra M. , El‐Mariah Fatma A. A. 
Published: December 2004

AbstractThe condensation of naphthalene‐1‐ or 2‐carbaldehyde with dimethyl 2,2‐dimethyl‐succinate (Stobbe conditions) gives predominantly the (Z)‐hemiesters 3 and 11a. The hemiester 3 contains a small amount of the (E)‐isomer. Similar condensation of naphthalene‐2‐carbaldehyde with dimethyl‐2‐methylsuccinate gave the hemiester (E)‐12a. Their configuration and the ratios of the (Z:E)‐hemiesters, their derived acids, anhydrides, indenones and phenanthrene derivatives are inferred by high resolution 1H‐n.m.r. spectroscopy.
Verbesserte Einsatzmöglichkeiten des 4‐Methoxybenzylrestes als 2′‐OH‐Schutz bei Ribonucleotidsynthesen durch TFA‐Acidolyse
Authors: Losse G. , Pechstein Birgit 
Published: December 2004

An Improved Method for the Application of the 4‐Methoxybenzyl Group to Protect the 2′‐Hydroxyl Group in the Ribonucleotide Synthesis by TFA‐acidolysisThe cleavage of the 4‐methoxybenzyl group from the 2′‐OH‐position of ribonucleosides by the hydrogenation with different Pd‐catalysts as well as trifluoracetic acid has been studied in detail. During hydrogenation, side reactions at the base residue of cytidine‐occurred which, however, could be extensively suppressed by PdCl2 catalysis. More practicable results were obtained with trifluoracetic acid in the presence of cation scavengers, allowing smoothly to convert a series of 2′‐methoxybenzyl ribonucleotides to the homogeneous deprotection products.
Substitution Reactions of 2‐(Aroyl, Methylidene)‐thiazolidine‐4‐on Derivatives
Authors: Zaleska Barbara , Winnik Witold 
Published: December 2004

AbstractThe reaction of 2‐(aroyl, methylidene)‐3‐arylthiazolidine‐4‐ones 1 with trifluoromethylsulfenyl chloride yields a mixture of geometric (Z, E) isomers of 2(aroyl, trifluorosulfenylmethylen)‐3‐aryl‐thiazolidine‐4‐ones 2. The bromination of 1 leads to 2‐(aroyl, methylidene)‐3‐aryl‐5‐bromothiazolidine‐4‐ones 3 which on reaction with nitrosobenzene formes nitrones 4. The structures of the compounds 2–4 were determined by means of n.m.r. and i.r. spectroscopy.
N‐Arylsulfonyl‐N′‐(pyrimidin‐4‐yl)ureas‐synthesis and reaction with dimethyl sulfoxide
Authors: Zeuner F. , Niclas H.‐J. 
Published: December 2004

AbstractThe N‐arylsulfonyl‐N′‐(pyrimidin‐4‐yl)ureas (3a–1) were synthesized by reaction of arylsulfonyl isocyanates (1) with 4‐amino‐2,6‐dialkylpyrimidines (2). Treatment of 3 with alkali or of 1 with an excess of 4‐amino‐2,6‐dimethylpyrimidine (2a) gave the salts 4a–e. Reaction of the ureas 3a–c with dimethyl sulfoxide at 90 to 120°C afforded N,N′‐bis(2,6‐dimethylpyrimidin‐4‐yl) ureas 8a–c. The reaction is assumed to involve a four‐centre mechanism with 5 as intermediate.
1H‐ und 13C‐NMR‐Spektren von N‐Methyl‐chinoliniumchalkonen: Bestimmung von σ‐Konstanten für die 2‐, 3‐ und 4‐Position des N‐Methyl‐chinoliniumrings
Authors: Radeglia R. , Bödeker J. , Fieblinger Dagmar 
Published: December 2004

1H‐ and 13C‐N.M.R. Spectra of N‐Methyl‐quinolinium Chalcones: Determination of σ‐Constants for the 2‐, 3‐ and 4‐Position of the N‐Methyl‐quinolinium RingFor the N‐methyl‐quinolinium chalcones 1a–c the 1H‐ and 13C‐n.m.r. data are reported. The unambiguous assignment of signals is based upon the 1H/1H homoshift and the 13C/1H heteroshift correlated 2D‐n.m.r. spectra. Using a Hammett relationship we have determined σ‐constants for the 2‐, 3‐ and 4‐position of the N‐methyl‐quinolinium ring from the 13C‐α chemical shifts of 1a–c. Their comparison with the σ‐values for the equivalent positions in the pyridine, N‐methyl‐pyridinium and quinoline ring indicates the additivity of anellation and quaternization effect.
Substituenteneffekte in den13C‐NMR‐Spektren von diastereomeren Chalkondihalogeniden. VIII. Untersuchungen an α‐ und β‐Halogendihydrochalkonen und Berechnung von13C‐chemischen Verschiebungen bei diastereomeren Chalkondihalogeniden und Chalkonhalogenhydrinen
Authors: Weber F. G. , Radeglia R. 
Published: December 2004

Substituent Effects in13C‐N.M.R. Spectra of Diastereomeric Chalcone Dihalogenides. VIII. Investigations of α‐ and β‐Halogene Dihydrochalcones and Calculation of13C‐chemical Shifts of Diastereomeric Chalcone Dihalogenides and Chalcone HalogenohydrinsThe chemical shifts of C‐α and C‐β in the13C‐n.m.r. spectra are determined and compared with calculated values from an incremental system and Taft relationship. The correlations are extended for erythro and threo isomers of halohydrins and diastereometric dihalogenides6–18.The chemical shifts of C‐α and C‐β atoms of6–18are described in the dependence of the shifts calculated by an incremental system. Excellent correlations allowed the computation of chemical shifts of C‐α and C‐β for diastereomeric α,β‐disubstituted dihydrochalcone derivatives likely6–18in advance.
New Red Diazonium Compounds based on 2‐amino benzene diazonium salts
Authors: Mustroph Heinz , Haessner Rainer 
Published: December 2004

AbstractUsing PMO theory the influence of substituents on the visible spectra of benzene diazonium salts is discussed. The theory explains the experimental structure‐colour relationships and allows to predict new basic structures of coloured benzene diazonium salts. The synthesis and spectral behaviour of the new class of superfast diazonium salts are described.
Fotochemische Primärprozesse von Xanthenfarbstoffen. X. Zum Einfluß ionischer Mizellen auf die Löschung der Fluoreszenz von Xanthenfarbstoffen durch Diazoniumionen
Authors: Ortmann W. , Wassiljuk I. , Fanghänel E. 
Published: December 2004

Photochemical Primary Processes of Xanthene Dyes. X. The Influence of Ionic Micelles on the Fluorescence Quenching of Xanthene Dyes with Diazonium IonsThe steady‐state and the time‐resolved fluorescence quenching of xanthene dyes by diazonium salts is investigated. The fluorescence of anionic dyes is more efficiently quenched than that of cationic dyes, due to the opposite charge. In the presence of anionic micelles the fluorescence quenching of cationic dyes by diazonium ions is more effective than in water, because the dye and diazonium ions are solubilized in the Stern region of the micelles. In the presence of cationic micelles the fluorescence of anionic dyes is effectively quenched by p‐dodecyloxybenzene‐diazonium salt solubilized in the micelles like a tensid ion. The equilibrium constants for the distribution of the diazonium ions between the micelles and the water phase are determined. The importance of the singlet state for the sensitized photolysis of diazonium salts is discussed.
The knoevenagel reaction of cyanoacetamide with β‐ketoanilides: Synthesis of polyfunctionally substituted pyridine and coumarine derivatives
Authors: Mohareb R. M. , Ibrahim N. S. 
Published: December 2004

AbstractCyanoacetamide undergoes a Knoevenagel condensation reaction with β‐ketoanilides 2a–c to give the acyclic products 3a–c. The reactivity of 3a towards the active methylene reagents, aldehydes, aryldiazonium salts and cinnamonitrile derivatives were studied.
Studies on 4‐thiazolidinones. VIII. The role of substituents at position‐3 on the mode of cleavage of 5‐Arylmethylene‐2,4‐dioxothiazolidines
Authors: Omar M. T. , Habashy M. M. , Youssef A. M. , Sherif F. A. 
Published: December 2004

AbstractHydrazine hydrate, morpholine and benzylamine react with 3‐aryl‐5‐arylmethylene‐2,4‐dioxothiazolidines 1a–d to give mixtures of thiolopropenamides 2, ethylideneamino‐biuret 3 and/or 4‐arylaminocarboxamides 4 in varying proportions. However, 3‐benzyl‐5‐arylmethylene 2,4‐dioxothiazolidines 1e–f afford mixtures of pyrazolinones 5 and 4‐benzyl‐hydrazinocarboxamide 6 upon treatment with hydrazine hydrate. The formation of these products is rationalized and discussed on the basis of the role of the substituent at the 3‐position. Structures 2–6 have been established.
Studies on the Autoxidation of Phenyl Cycloalkanes
Authors: Batke Birgit , Lauterbach Gerlinde , Pritzkow Wilhelm , Voerckel Volkmar , Belyakov Vladimir A. 
Published: December 2004

AbstractThe products of the autoxidation of phenyl cyclopropane (I), phenyl cyclobutane (II), phenyl cyclopentane (III), phenyl cyclohexane (IV), phenyl cycloheptane (V) and phenyl cyclooctane (VI) were analyzed after reduction of the reaction mixtures with LiAlH4. As products of the attack on the α‐CH bonds the corresponding 1‐phenyl cycloalkanols and 1‐phenyl alkan‐1‐ols were found. In the case of phenyl cyclopropane some SR2 ring opening probably takes place.The oxidabilities \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm k}_{\rm p} /\sqrt {{\rm k}_{\rm t}} $\end{document}, the chain termination constants kt, the absolute chain propagation constants kp and the relative chain propagation constant (kp)rel were determined for the phenyl cycloalkanes I—VI. As it is to be expected on the basis of the I‐strain concept the autoxidation rate of phenyl cyclopentane (III) is considerably higher than that of phenyl cyclobutane (II) and phenyl cyclohexane (IV).
Studies on aminoazoles: Synthesis of Pyrazolo[1,5‐a]‐pyrimidines and their aza derivatives
Authors: Elgemeie Galal H. , Elghandour Ahmed H. , Elshimy Hamdy M. 
Published: December 2004

AbstractThe reaction of 4‐arylazo‐3‐aminopyrazol‐5‐ones (1a–i) with α,β‐unsaturated nitriles, active methylene reagents and nitrile imines are reported. They lead to new polyfunctional derivatives of pyrazolo[1,5‐a]pyrimidine (5a–c, 6, 10a–i, 13a–c, 14a–c, 17a–d, 15), pyrazolo‐[5,1‐c]‐1,2,4‐triazine (22a–i) and pyrazolo[5,1‐c]‐1,2,4‐triazole (25a–c).The structures of these products and the mechanisms of their formation are reported.
Zur elektrochemischen Darstellung des 1,1‐Dichlor‐4‐methylpenta‐1,3‐diens
Authors: Fechtel U. , Matschiner H. 
Published: December 2004

Electrochemical Synthesis of 1,1‐Dichloro‐4‐methylpenta‐1,3‐dieneReaction of 1,1,1‐trichloro‐4‐methylpent‐3‐en‐2‐ol (2) with inorganic acid halides yielded several polychloroalkenes (3–5). These compounds were utilized for the electrochemical synthesis of 1,1‐dichloro‐4‐methylpenta‐1,3‐diene (1).
Azole. 22.. 1H‐ und 13C‐NMR Untersuchungen an isomeren 3‐ und 5‐Amino‐pyrazol‐Derivaten
Authors: Bernard M. K. , Wrzeciono U. 
Published: December 2004

Azoles. 22. 1H‐ and 13C‐N.M.R. Investigation of Isomeric‐3 and 5‐Amino‐Pyrazole DerivativesThe 1H‐ and 13C‐n.m.r. spectra of nine pairs of isomeric 3‐ and 5‐amino‐pyrazole derivatives 1a—1i and 2a—2i and some of their acetylderivatives have been assigned and discussed. It has been found that 1H‐ and 13C‐n.m.r. spectroscopy is a useful tool for differentation of the above mentioned 3‐ and 5‐amino‐isomers.
Inter‐ und intramolekulare Acylwanderungen an 1(9)H‐2,3‐Dihydro‐imidazo[1,2‐a]benzimidazolen
Authors: Graubaum H. , Ozegowski R. 
Published: December 2004

Inter‐ and Intramolecular Acyl Transfer on 1(9)H‐Imidazo[1,2‐a]benzimidazolesThe new imidazo[1,2‐a]benzimidazoles (3) react with electrophiles like aroyl chlorides, isocyanates, cyanates, chloroformates and chlorothioformates to give the 9‐acyl derivatives (4a–1).At higher temperatures intermolecular acyl transfer takes place to give the l‐acyl compounds (5a–m). In the case of 1‐carbamoyl imidazo[1,2‐a]benzimidazoles (5) was observed intramolecular acyl transfer in the presence of strong bases and 1‐benzimidazol‐2‐yl‐hydantoins (6) were isolated.The structures of the prepared compounds could be inferred from their 1H and 13C n.m.r., mass spectra and were corroborated by the comparison with the data of similar derivatives as well as by chemical means.
Synthese und Reaktionen von N‐Phthalimido‐keten‐S,S‐acetalen
Authors: Dölling W. , Herrmann Cornelia , Augustin M. , Giering Susanne 
Published: December 2004

Synthesis and Reactions of N‐Phthalimido‐ketene‐S,S‐acetalsN‐substituted phthalimido derivatives 1a–f react in the presence of bases (NaH, t‐BuONa) with carbon disulfide to the N‐phthalimido‐ketene‐S,S‐acetals 3, 4, 5 and 6, respectively. 2‐Amino‐ketene‐S,S‐acetals 7a–c are formed by reaction of 3a, b or 5a with hydrazine hydrate. 3c produces with phenylhydrazine the pyrazole 8, and with piperidine and pyrrolidine the E/Z mixture of the corresponding ketene‐S, N‐acetals 9a,b. 1c is transformed into 10a–c (E/Z‐mixture)by treatment with phenylisothiocyanate under basic condition followed by alkylation.
Diskussionsbeitrag zur Normung der Ermittlung der Sprengenergie unter Wasser
Authors: Christmann W. , Lingens P. 
Published: December 2004

AbstractDer Versuchsaufbau zur Ermittlung der Sprengstoffenergie unter Wasser wird zur Vereinheitlichung vorgeschlagen. Die Form und das Gewicht der Sprengladung werden unter Berücksichtigung der verfügbaren Größe des Wasserbehälters diskutiert. Die Messung der Zeit zwischen der Detonation der Sprengladung und dem ersten Zusammenschlagen der Gasblase und die Auswertung der Meßergebnisse mit Hilfe der Formel von Cole werden ebenfalls zur Normung empfohlen. Die Messung der Stoßwellenenergie und die Auswertung der Meßergebnisse können noch nicht vereinheitlicht werden. Hierzu müssen noch weitere Arbeiten durchgeführt werden.
Application of Safety Testing Methods of Explosives to Firedamp and coal dust and comparison to blasting safety methods in collieries
Authors: Gorol C. , Sobala J. 
Published: December 2004

AbstractRequirements are discussed which must be fulfilled by laboratory and field tests in methane und coal dust before an explosive is permitted for use in mine. Based on results of explosive testing done in recent years in Poland and on results of our continual research, basic differences were found in the ignition ability of methane and coal dust. The differences were also found in laboratory tests using steel mortars which simulate boreholes, and in field tests in underground roadways. With respect to these findings the safety of mining explosives in methane and coal dust and their applicability in the mining practice are discussed.
Characterization of BAMO/NMMO Copolymers
Authors: Kimura Eishu , Oyumi Yoshio , Kawasaki Hidetoshi , Maeda Yuko , Anan Toshiyuki 
Published: December 2004

AbstractThe compositions and microstructures, thermolyses, and sensitivities of 3,3‐bis(azidomethyl)oxetane (BAMO) copolymers with 3‐nitratomethyl‐3‐methyloxetane (NMMO) were characterized. The molar ratios of monomers fed in the copolymerizations were: BAMO/NMMO = 8/2, 7/3, and 6/4. The observed compositions were 81/19, 68/32, and 60/40, respectively. The relative compositions of trade microstructures were also exactly the same as theoretical values. The copolymerization of BAMO with NMMO behaved like an ideal system in the sense that the copolymer has approximately the same composition as the monomer fed. The microstructures of copolymers were also randomly arranged. Poly BAMO showed side chain decomposition in the initial stage of the thermolysis, on the other hand, backbone decomposition controlled the thermolysis of poly NMMO. The BAMO units and the NMMO units appeared to decompose more or less independently of one another and retained their individual decomposition characteristics despite being copolymerized. However, the heat generated by the NMMO decomposition, which occurred at 40°C lower than that of BAMO. activated the reaction of BAMO. Poly B/N(7/3) showed very interesting characteristics in sensitivities, mechanical properties, and the heat of decomposition.
Synthesis of N, N′ ‐Bis(2, 4‐Dinitrobenzofuroxanyl)‐3, 5‐Dinitro‐2, 6‐Diaminopyridine
Authors: Naixing Wang , Boren Chen , Yuxiang Ou 
Published: December 2004

AbstractN,N′‐Bis(2,4‐dinitrobenzofuroxanyl) ‐3,5‐dinitro‐2,6‐diaminopyridine has been synthesized from 2,6‐diaminopyridine and trinitrodichlorobenzene. For this compound, the structure has been determined by elemental analysis, IR,1HNMR and MS spectroscopies.
Thermal decomposition features of ammonium nitrate and its boron mixture under high pressures
Authors: Koroban V. A. , Burtsev Yu. N. , Alimov F. R. , Haustov A. D. , Dubovik V. A. , Teselkin V. A. 
Published: December 2004

AbstractThe kinetics of ammonium nitrate thermal decomposition was studied by the differential thermal analysis in the pressure range from atmospheric to 1.0 GPa. The decomposition under pressure was shown to obey the zero‐order equation with a constant proportional to the initial HNO3 concentration in the sample. The structural transitions in ammonium nitrate were found to affect its exothermic interaction with boron. The mechanism of this phenomenon was interpreted. The experimental data allowed to establish volume changes on melting ammonium nitrate, equal to 0.072 cm3/g.
Evaluation of pyrotechnic smoke for anti‐infrared and anti‐laser roles
Authors: Singh Amarjit , Avachat S. G. , Joshi S. A. , Singh Haridwar 
Published: December 2004

AbstractThis paper describes the experimental setup for evaluation of pyrotechnic smoke compositions for anti‐laser and anti‐infrared roles using the continuous wave 10.6 μm CO2 laser (4 watt) and presents the results for a few pyrotechnic smoke compositions. The particle sizes of the aerosol from pyrotechnic smoke compositions were also determined using Quartz crystal Microbalance ‐ Cascade Impactor. Two smoke compositions containing hexachloroethane, anthracene/naphthalenee, potassium perchlorate and magnesium powder showed more than 97% attenuation of CO2 laser, whereas a composition containing zinc oxide, aluminium, iron oxide along with hexachlorocthane was least effective.
Wellenmechanische Absolutrechnungen an Molekülen und Atomsystemen mit der SCFMOLC(LCGO) Methode. I. Das Cyclopentadienylanion (C5H)
Authors: Preuss H. , Diercksen G. 
Published: December 2004

AbstractDas C5H wird im Gleichgewichtsabstand der Zentren unter Berücksichtigung aller 36 Elektronen ab initio mit Hilfe des Allgemeinen Programmsystems/SCFMOLC(LCGO) Methode berechnet. Es ergibt sich eine Gesamtenergie von −189,42 a.E. Die Ionisierungsenergie (Elektronenaffinität des C5H5) beträgt 0,9 eV. Bei den Einteilchenenergien sind in energetischer Folge den π‐Zuständen σ‐Zustände eingelagert.
Extended Hartree–Fock calculations for the helium ground state
Authors: Lefebvre Roland , Smeyers Yves G. 
Published: December 2004

AbstractThe extended Hartree–Fock (EHF) wave function of an n‐electron system is defined (Löwdin, Phys. Rev. 97, 1509 (1955)) as the best Slater determinant built on one‐electron spin orbitals having a complete flexibility and projected onto an appropriate symmetry subspace. The configuration interaction equivalent to such a wavefunction for the 1S state of a two‐electron atom is discussed. It is shown that there is in this case an infinite number of solutions to the variational problem with energies lower than that of the usual Hartree–Fock function, and with spin orbitals satisfying all the extremum conditions. Two procedures for obtaining EHF spin orbitals are presented. An application to the ground state of Helium within a basic set made up of 4(s), 3(p0), 2(d0) and 1 (f0) Slater orbitals has produced 90% of the correlation energy.
Wellenmechanische Absolutrechnungen an Molekülen und Atomsystemen mit der SCFMOLC(LCGO) Methode. VII. Das System (LiH2)−
Authors: Preuss H. , Diercksen G. 
Published: December 2004

AbstractDas System (LiH2)− wurde für eine Reihe von Kernlagen unter Berücksichtigung aller 6 Elektronen mit dem Allgemeinen Programmsystem SCFMOLC(LCGO) Mathode berechnet. Es ergab sich, dass für die lineare Anordnung (RLiH = 3,5 ± 0,2 a.E.) ein metastabiles Molekül vorliegt, dessen Gesamtenergie um 0,12 a.E. tiefer liegt als das System der getrennten Atome. Dagegen kann (LiH2)− über einen Potentialberg in Li− + H2 zerfallen, welches um 0,01 a.E. tiefer liegt. Die Höhe des Potentialberges beträgt 0,15 a.E. Die Energiehyperfläche wird graphisch dargestellt und im Einzelnen die Bildung (und der Zerfall) von (LiH2)− diskutiert.
Wellenmechanische Absolutrechnungen an Molekülen und Atomsystemen mit der SCFMOLC(LCGO) Methode. X. Das Methylkation (CH3)+
Authors: Von Bünau G. , Diercksen G. , Preuss H. 
Published: December 2004

AbstractDas (CH3)+ wurde unter Berücksichtigung aller 8 Elektronen ab initio mit dem Allgemeinen Programmsystem/SCFMOLC(LCGO) Verfahren berechnet. Es ergab sich nach Variation des CH Abstandes und der Lage des C Atoms, dass (CH3)+ eben gebaut ist, mit einem Bindungsabstand RCH = 2,05 a.E. Die beiden Kraftkonstanten (Atmungsschwingung, Winkelschwingung) ergeben sich dabei zu k1 = 18,9 mdyn/Å und k2 = 3,3 mdyn/Å mit den zugehörigen Wellenzahlen ω1 = 3256 cm−1 und ω2 = 1526 cm−1. Die Ionisierungsenergie wurde zu I = 25,75 eV bestimmt. Die Elektronenaffinität wurde zu A = 5,4 eV abgeschätzt.