Zur gruppentheoretischen Bestimmung der Atomzustände in Ligandenfeldern

Zusammenfassung Es wird vorgeschlagen, die Bezeichnungen weak-field-Methode bzw. strong-field-Methode durch (L)-Methode bzw. ()-Methode zu ersetzen.Nach einer kurzen Einführung in die ()-Methode wird mit den Mitteln der Gruppen-und Darstellungstheorie eine Formel abgeleitet, mit deren Hilfe man schnell Rasse und Multiplizität der Terme eines Komplexions in der ()-Methode angeben kann. Einige Spezialfälle dieser Formel und die systematische Bestimmung der ()-Funktionen werden erörtert.

---

It is suggested that the misleading designations weak field method and strong field method be replaced by (L) method and () method, respectively.Following a brief introduction to the () method an equation is derived by group theoretical means which leads to rapid classification of the () terms. Several special cases and short cuts are discussed as well as the systematic determination of the () functions.

---

Résumé Le remplacement des termes «méthode du champ faible» et «méthode du champ fort» par «méthode (L)» et «méthode ()» est proposé.Après une introduction dans la méthode () une formule est dérivée à l'aide de la théorie des groupes et des représentations, qui donne la représentation irréductible et la multiplicité des termes d'un ion complexe dans le cadre de la méthode (). Quelques cas spéciaux de cette formule et la détermination systématique des fonctions (/gG) sont discutés.

---

---

Ich danke Herrn Professor Dr. H. Hartmann für den Hinweis auf das vorliegende Problem und der Deutsehen Forschungsgemeinschaft für ein Stipendium.     

Reaction of Cytisine with 4″-Substituted Dibenzo-18-crown-6 Sulfonylchlorides

Sulfamides were synthesized via the reaction of cytisine with 4,4(5)-dibenzo-18-crown-6-disulfonyl-, 4-sec-butyl-4(5)-dibenzo-18-crown-6-sulfonyl-, and 4-acetyl-4(5)-dibenzo-18-crown-6-sulfonylchlorides. The structures of the prepared compounds were confirmed by PMR.     

Coumarins ofHaplophyllum ramosissimum

Summary 7-(3,3-Dimethylallyloxy)-6-methoxycoumarin and two new coumarins — ramosin and ramosinin — have been isolated from the epigeal part ofHaplophyllum ramosissimum.On the basis of IR, PMR, and mass spectroscopy and chemical reactions, the structure of 8-(3,3-dimethylallyl)-7-(3,3-dimethylallyloxy)coumarin (II) has been proposed for ramosin and that of 3-(1,1-dimethylallyl)-8-(3,3-dimethylallyl)-7-methoxycoumarin (III) for ramosinin.Leningrad Sanitary-Hygienic Medical Institute. Institute of Chemistry, Academy of Sciences of the Turkmen SSR, Ashkhabad. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 15–17, January–February, 1979.     

Studies of 2,3′-biquinolyl. 6. Regioselectivity of nucleophilic addition of organometallic compounds to 1-aklyl-3-(2-quinolyl)quinolinium halides

Nucleophilic addition of organometallic lithium and magnesium compounds to 1-alkyl-3-(2-quinolyl)quinolinium cations produces a mixture of the corresponding 1-alkyl-2-R-1,2-dihydro-2,3-biquinolyls and 1-alkyl-4-R-1,4-dihydro-2,3-biquinolyls. The portion of the latter decreases with increasing hardness of the organometallic compound.For No. 5, see [1].Stavropol State University, Stavropol'355009, Russian Russian Chemical Technology University Moscow 125190 Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 919–923, July, 1999.     

Catalytic properties of nickel phosphates. Isomerization of butenes

The effect of calcination temperature on the catalytic properties of nickel phosphate has been studied using the isomerization of butene-1 as a test reaction. A simple relationship was found between the catalyst activity in isomerization and the hydroxy content of the catalyst surface. Interrelations between the activity of the catalyst and its structure are discussed.

---

, -1 . . .

     

Anomalous nucleosides

By the condensation of the mercury salt of benzotriazole with acetylpentosyl bromides in xylene, we have synthesized 1-benzotriazolyl-2,3, 4-tri-O-acetyl--D-ribo- and-xylopranosides, the deacetylation of which has given anomalous nucleosides- antimetabolites of nucleic metabolism: 1-benzotriazolyl--D-ribopyranoside and 1-benzotriazolyl-- D-xylopyranoside.For part IX, see [9].     

Syntheses of 6N(N′-formyl-D-phenylalanyl)-deoxyamino-β-cyclodextrin and 6N(N′-formyl-L-phenylalanyl)deoxyamino-β-cyclodextrin and their inclusion behavior

6N(N-formyl-D-phenylalanyl)-deoxyamino--cyclodextrin and 6N(N-formyl-L-phenylal-anyl)-deoxyamino--cyclodextrin (I andII) were prepared. These new hosts formed intramolecular host-guest complexes and included naphthyl derivatives preferentially with a stoichiometry of 1:1. The inclusion behavior was different between I and II because the cavity shape formed with the CD cavity and the phenylalanine moiety of I was different from that of II.     

Synthesis and alkylation of 4,6-diphenyl-3-thiocarbamoyl-3,4,5,6-tetrahydropyridine-2(1H)-one and 4,6-diphenyl-3-thiocarbamoyl-3,4-dihydropyridine-2(1H)-one

Alkylation of 3-thiocarbamoyl-3,4,5,6-tetrahydropyridine-2(1H)-one with methyl iodide has given 5-methylthio-2,6-diazabicyclo[2.2.2]oct-5-en-3-one and 3-methyl-thiocarbonyl-3,4-dihydropyridine-2(1H)-one. Alkylation of 3-thiocarbamoyl-3,4-dihydridine-2(1H)-one with iodoacetamide affords 3-(1-amino-1-carbamoyl-3,4-methyl-thiomethylene)-1,4-dihydropyridine-2-one, which in acidic media is converted into 3-(4-oxo-3,5-dihydro-1,3-thiazol-2-ylidene)-1,4-dihydropyridine-2-one.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 787–794, June, 1989.     

Organodimagnesium derivatives of thiophene. 3. Synthesis of an organodimagnesium derivative of hexabromo-2,2′-dithienyl and its reaction with oxalic acid esters

It was established that the reaction of hexabromo-2,2-dithienyl with magnesium in the presence of ethyl bromide gives an organodimagnesium derivative, which reacts with oxalic acid esters to give 3,3,4,4-tetrabromo-5,5-dithienyl-diglyoxalic acid esters. Reduction of the latter with ethylmagnesium bromide leads to 3,3,4,4-tetrabromo-5,5-dithienyl-2,2-diglycolic acid esters.See [1] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 468–470, April, 1981.     

Propagation of vibrational excitation in an adsorbed layer

Using a crystal model with an adsorbed layer, the propagation of vibrational excitation induced by an adsorbed particle is considered. The relaxation times of excitation have been estimated. The role of excitation transfer processes in adsorption-desorption phenomena is discussed.

---

, . . - .

     

The structure of smyrnioridin

Conclusions A new coumarin, which has been called smyrniodidin, has been isolated from the roots ofSmyrniopsis aucheri acetoxy-1-methylethyl)-4-angeloyloxy-4,5dihydrofuro-2, 3: 7, 6-coumarin. Boiss. The NMR spectrum and a study of the saponification products of smyrnioridin have shown that it is 5-(1-     

Reversed phase liquid chromatographic retention behavior of polystyrene homopolymers

Summary Isocratic and gradient elution high performance liquid chromatographic measurements of the retention behavior of polystyrene homopolymers with molecular weights ranging from 2 kD to 390 kD were performed using mixed methylene chloride-methanol mobile phases of varying composition and a C-18 chemically bonded stationary phase supported on either 100 Å or 300 Å mean pore diameter silica. Isocratic measurements of the capacity factor, k, for different molecular weight homopolymers as a function of the volume fraction of methylene chloride, , permit determination of the critical composition, _c, which renders k=1 and the local slope, S=–lnk/_c of the lnk- isotherm at =_c, and also the dependence of _c and S on the degree of polymerization, M. Linear gradient elution measurements of _c and S were also performed and compared to the corresponding isocratic measurements. The general retention behavior and the dependence of _c and S on M compare favorably to the predictions of the theory of homopolymer retention and fractionation developed by Boehm, Martire, Armstrong, and Bui (BMAB). Comparison is also made between the present work and the experimental observations of other workers on related chromatographic systems involving hompolymer retention.     

Thiazolobenzo-1, 2, 3-thiadiazoles and derived cyanine dyes

The following tricyclic heterocyclic compounds are synthesized: 2-methylthiazolov (5, 4-e) benzo-1, 2, 3thiadiazole, 2-methylthiazolo (4, 5-e) benzo-1, 2, 3-thiadiazole, 2-methylthiazolo (4, 5-g) benzo-1, 2, 3-thiadiazole, and 2-methylthiazolo (5, 4-g) benzo-1, 2, 3-thiadiazole. The quaternary salts of these bases are used to prepare symmetrical and unsymmetrical trimethinecyanines and dimethinemercocyanines containing N-ethylrhodanine residues. The absorption maxima of these dyes are shifted toward the long-wave region as compared with the corresponding thiacyanines.     

Use of electrostatic interaction for chiral recognition. Enantioselective complexation of anionic binaphthyls with protonated amino-β-cyclodextrin

The studies using NMR and capillary zone electrophoresis clearly reveal that protonated 6^A-amino- 6^A-deoxy--cyclodextrin recognizes the chirality of anionic binaphthyl derivatives such as 1,1-binaphthyl-2,2-diyl phosphate and 1,1-binaphthyl-2,2-dicarboxylate through electrostatic interaction between the host and the guest and simultaneous inclusion.     

New chiral acyclic analogs of 2′-deoxynucleosides

Convenient methods for the synthesis of chiral 2,3-seco-2-deoxynucleosides were developed. An isopropylidene protective group was used to block the 3,5-hydroxy groups in 2,3-seco-uridine. Conversion of the hydroxymethyl group to a methyl group was accomplished by chlorination with a mixture of CCl₄ and Ph₃P with subsequent reduction with n-Bu₃SnH. 2,3-seco-2-Deoxyuridine was obtained after deacetonation. The (S) enantiomer was similarly synthesized starting from 1-(-D-arabinofuranosyl)uracil. 3-O-tert-Butyldimethylsilyl-5-O-(p-monomethoxytrityl)-2,3-seco-2-deoxyuridine, which has optically active centers at C₍₁₎ and C₍₄₎, was also synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 822–826, June, 1988.The authors thank Professor M. Ya. Karpeiskii for his constant interest in this research.     

The electronic structure of molecules by a many-body approach

The vertical valence ionization potentials of cyclopropane, ethylene oxide and ethylene imine are calculated by a many-body Green's function method. For C₃H₆ the ordering of the ionization potentials is 2e(), 1e(), 2a₁(), 1a₂(), 1e(). The assignment of the 2a₁ and the 1a₂ ionization potentials which has been controversial is thus clarified. The ordering is in agreement with the result obtained via Koopmans' theorem. For ethylene oxide and ethylene imine Koopmans' theorem fails in predicting the correct order of ionic states. For C₂H₄O the ordering of the ionization potentials is 2b ₁(), 4a ₁, 1a ₂(), 2b ₂,3a ₁, 1b ₁(), 1b ₂, 2a ₁ and for C₂H₅N 6a, 5a, 3a, 2a, 4a, 3a, 1a, 2a. The agreement of the computed ionization potentials with the experimental values is very satisfactory.     

Reaction of dibepin with amino acids on chromatographic paper

A method was developed for the development of amino acids and some of their derivatives on Chromatographic paper by means of dibepin-8-[2,3(CO),6,5(CO)-dibenzoylene-4-pyridyl]-l-naphthoyl chloride. The sensitivity was 2 g in the case of glycine ethyl ester hydrochloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 357–358, March, 1972.     

Reactions of pennogenin and related compounds. IV. Formation of (25R,22′R,25′R)-3β,3′β-diacetoxy-26,22′-epoxy-16,16′-bifurosta-5,20(22),5′,17′(20′)-tetraen-26′-ol from pennogenin diacetate under the action of BF3·Et2O

A new direction of the reaction of pennogenin diacetate with BF₃·Et₂O has been discovered in which a previously unknown dimeric steroid is formed — (25R,22R,25R)-3,3-diacetoxy-26,22-epoxy-16,16-bifurosta-5,20(22), 5,17(20)-tetraen-26-ol, the structure of which has been established as the result of an analysis of IR, UV,¹H and¹³C NMR, and mass spectra. A probable mechanism for the formation of the title compound from pennogenin diacetate is suggested.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Institute of Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 202–208, March–April, 1990.     

Synthesis and structure of o-bis(2-fluoro-2,2-dinitroethyl)-nitromethyl ester of 2′-fluoro-2′, 2′-dinitroethyl-2″-fluoro-2″-nitroethylenecarboxime

Conclusions The product of conversion of O-bis(2-fluoro-2,2-dinitroethyl)nitromethylbis(2-fluoro-2,2-dinitroethyl)carboxime in methanol or ether is O-bis(2-fluoro-2,2-dinitroethyl)nitromethyl-2-fluoro-2,2-dinitroethyl-2'-fluoro-2-nitroethylenecarboxinie, the structure of which has been established by x-ray diffraction analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2019–2021, September, 1987.