R?ntgenstrukturanalyse als unentbehrliches Hilfsmittel bei der absoluten Konfigurationszuordnung einiger Iridoidglucoside sowie daraus synthetisierter 12-epi-Prostaglandine

Ohne Zusammenfassung

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X-ray-structure-analysis as indispensable tool in structure elucidation of some iridoidglucosides as well as 12-epi-prostaglandines derived from them

Abkürzungen C(OH)₄ -d-Glucopyranosyl - Ac CH₃—CO - Ts p-CH₃—C₆H₄—SO₂ - Cin C₆H₅—CH=CH—CO - HCin C₆H₅—CH₂—CH₂—CO—O - DME Dimethoxyethan     

Matrix-isolation Raman spectroscopy and photochemistry of carbonyl-metal-silyl complexes

To study the photochemistry of metal-silyl complexes the compounds Cp(CO)₂Fe-SiH₂(CH₃) (Cp = ⁵–C₅H₅) and Cp*(CO)₂((CH₃)₃P)Mo-SiH₃ (Cp* = ⁵–C₅(CH₃)₅) have been isolated in krypton or nitrogen matrices and subsequently detected by Raman spectroscopy. Vibrational assignments for the two compounds are given. Furthermore, differences in the Raman spectra induced by UV irradiation are discussed.     

Competition between H<Subscript>2</Subscript>O and CH<Subscript>3</Subscript>OH molecules in the formation of the simplest stable proton disolvates and their solvation in aqueous methanol solutions of KOH and CH<Subscript>3</Subscript>OK

IR spectroscopic and quantum chemical methods are used to study the competition between water and methanol molecules in the formation of the simplest stable proton disolvates and their subsequent solvation in the case of solutions of KOH in CH₃OH and CH₃OK in H₂O with similar stoichiometries (~1:3-3.5). The complexes found in these solutions are analysed to determine their composition and structure: they are found to be heteroions (CH₃O?H?OH)^– solvated by two similar solvent molecules. In both cases, there are virtually no complexes of the second possible type (CH₃OH·(CH₃O?H?OCH₃)^–··H₂O or CH₃OH·(HO?H?OH)^–·H₂O), which appears to be due to the stoichiometric compositions of the solutions. It is shown that a DFT calculation (B3LYP/6-31++G(d,p)) of linear complexes with strong (~15-30 kcal/mol) H bonds reproduces, with good accuracy, the IR spectra of the solutions, which consist mainly of these complexes.     

Mechanism of the radiolytic transformation of cellulose

The formation under -irradiation of volatile products in cellulose preparations with different degrees of crystallinity has been studied. The volatile products of the radiolysis of cellulose have been found to contain H₂, CH₄, H₂O, CO, and C0₂. According to the results obtained, these products can be divided into two groups, the first of which (H₂, H₂O, and CO) is formed as the result of the splitting out of hydrogen atoms and of —OH and —CH₂OH groups from the macromolecule, while the second (CH₄ and CO₂) is the result of radiation-chemical reactions between the components of the volatile products of the first group.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 921–927, November-December, 1996. Original article submitted February 26, 1996.     

New ferrocenylmethylphosphines - Preparation, characterisation and coordination chemistry of PH(CH2Fc)2, P(CH2Fc)3 [Fc = Fe(η-C5H5)(η-C5H4)] and their derivatives

The new ferrocenylmethylphosphines PH(CH₂Fc)₂ (1) [Fc = Fe(η⁵-C₅H₅)(η⁵-C₅H₄)] and P(CH₂Fc)₃ (2) and the phosphonium salt [P(CH₂Fc)₃(CH₂OH)]I (3) were synthesised from P(CH₂OH)₃ and [FcCH₂NMe₃]I. [P(CH₂Fc)(CH₂OH)₃]Cl (4) was obtained from P(CH₂Fc)(CH₂OH)₂, CH₂O and HCl. The new phosphines and phosphonium salts were fully characterised by NMR and IR spectroscopy and MS. [Mo(CO)₆] reacts with 1 to give [Mo(CO)₅{PH(CH₂Fc)₂}] (5) in high yield, but attempts to employ 2 as a ligand failed. The reaction of [P(CH₂Fc)₃(CH₂OH)]I (3) and [PH(CH₂Fc)₃]I (obtained in situ from 3 and Na₂S₂O₅) with [WI₂(CO)₃(NCMe)₂] gave the complex salts [P(CH₂Fc)₃(CH₂OH)][WI₃(CO)₄] (6) and [PH(CH₂Fc)₃][WI₃(CO)₄] (7), respectively. [P(CH₂Fc)₄]I (8) was synthesized from PH₂CH₂Fc and [FcCH₂NMe₃]I. Crystal structures were obtained for 1, 3-8.     

Some transesterification reactions of [Ir(CO2Me)(CO)2(PPh3)2]

The iridium(I) complex [Ir(CO₂Me)(CO)₂(PPh₃)₂] undergoes a transesterification reaction with the alcohols CH₂C(R)CH₂OH (R = H, Me), MeCCCH₂CH₂OH, and HOCH₂CH₂OH to afford the complexes

[Ir(CO₂CH₂CH₂CMe)(CO)₂(PPh₃)₂] and [Ir(CO₂CH₂CH₂OH)(CO)₂(PPh₃)₂], respectively. In contrast the acetylenic alcohol HCCCH₂CH₂OH gives [Ir(CCCH₂CH₂OH)(CO)PPh₃)₂]. Some reactions of the new complexes are described.     

Solubility and Thermodynamics of Solvation of Krypton in Mixtures of H/D Isotopomers of Water and Methanol at 101325 Pa and 278-318 K

The solubility of krypton in mixtures of H/D isotopomers of water (H₂O, D₂O) and methanol (CH₃OH, CD₃OH, CH₃OD) was studied at 101325 Pa and 278.15-318.15 K with a 10 K step. The thermodynamic characteristics of Kr solvation were calculated. The densities of mixtures of water and methanol isotopomers at the examined temperatures were calculated with an error of no more than 1 × 10^{- 5} g cm^{- 3} in the entire composition range. Both in water and aqueous methanol, krypton behaves as a structure-making component, but the alcohol solvation surrounding of the Kr atoms is more labile and more susceptible to the breaking effect of temperature.     

Sila-Riechstoffe und Riechstoff-Isostere, 13. Mitt.Grimmsche Hydridisostere im Bereich der Duftstoffklasse des Linalools

Summary Substitution of the (CH₃)₂CH=CH group by (CH₃)₂C=N in linalool as well as by the (CH₃)₂CH-CH₂ group in linalool and in sila-linalool does not lead to noticeable changes of their scent qualities. On the contrary, substitution of the OH group at the tertiary C atom by NH₂ or CH₃ — hydride isosteric to OH according toGrimm — affords fishy or etheric instead of the original flowery smells thus indicating a transition to different basic classes of odor. Similar results were obtained with the linalool-like scents of benzyldimethylcarbinol and phenylethyldimethylcarbinol. Therefore the theory ofAmoore, after which only shape and size of molecules are ruling their odor qualities, must be called in question.

     

Reaction of α,α,ω-trichloro- and α,α,α,ω-tetrachloroalkanes with alkali metal acylates in aprotic solvents

Polychloroalkanes and -alkenes R(CH₂)_nCl (R=CHCl₂CH₂, CCl₂=CH, n=1, 3) in dipolar aprotic solvents — dimethylformamide (DMF), dimethylsulfoxide (DMSO), hexamethylphosphoramide (HMPA) — at 130–150°C react selectively at the CH₂Cl group with salts of carboxylic acids RCO₂K(Na) to form dichloroesters RCO₂· (CH₂)_nR (R=CHCl₂CH₂, CCl₂=CH). In tetrachloroalkanes CCl₃CH₂(CH₂)_nCl (n = 1, 3, 5) under the same conditions the selectivity of the CCl₃ and CH₂Cl groups relative to the nucleophile RCO₂K(Na) is altered — unsaturated esters RCO₂(CH₂)_nCH=CCl₂ are formed in one stage with yields of 75–90%. Under the selected conditions, high conversion of polychloroalkanes to esters is attained 3 to 5 times more rapidly than in acid media. The structure of the ester obtained has been confirmed by their PMR spectra.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2790–2793, December, 1990.     

Reactions of Co2(CO)8 and of Co2(CO)6L (L = 3-pentyn-1-ol, 1,4-butyn-diol or 2-methyl-3-butyn-2-ol) with 2(diphenylphosphino)ethyl-trietoxysilane and tris(hydroxymethyl)phosphine for applications to new sol-gel materials

The complex Co₂(CO)₆[μ-η²-(H₃CCCCH₂CH₂OH)] (1) with the ligand 3-pentyn-1-ol (pol) has been synthesized following established procedures. Its structure has been determined by X-ray analysis. The complex Co₂(CO)₆(mbo) (mbo = 2-methyl-3-butyn-2-ol, HCCC(CH₃)₂OH), (3), along with the already known Co₂(CO)₆(bud) (bud = 1,4-butyn-diol, HOCH₂CCCH₂OH) (2), and Co₂(CO)₈ were reacted with 2(diphenylphosphino)ethyl-triethoxysilane [Ph₂PCH₂CH₂Si(OCH₂CH₃)₃] (dpts) and tris(hydroxymethyl)phosphine [P(CH₂OH)₃] (thp). With dpts, mono- and di-substituted complexes were obtained: these were characterized by analytical and spectroscopic techniques. The structures of Co₂(CO)₆(dpts)₂ (5) and of Co₂(CO)₄(pol)(dpts)₂ (8) have been determined by X-ray analysis.Complex (1) was reacted with 3-(triethoxysilyl)propyl isocyanate [(H₃CCH₂O)₃Si(CH₂)₃NCO] (tsi): the new complex Co₂(CO)₆[H₃CCCCH₂CH₂OC(O)NH(CH₂)₃Si(OCH₂CH₃)₃] (9) was obtained and spectroscopically characterized. The complex has also been reacted with tetraethyl orthosilicate (teos); a new inorganic-organometallic material was obtained. Complex (5) has been grafted on the mesoporous material SBA-15. The hybrid inorganic-organometallic materials obtained have been characterized by inductively coupled plasma-mass spectrometry (ICP-MS), infrared spectroscopy (FT-IR) under vacuum conditions, X-ray diffraction (XRD) and scanning electron microscopy coupled to EDS probe (SEM-EDS).     

Partial oxidation and oxidative condensation of methane with the participation of N2O on a V2O5/SiO2 catalyst

The catalytic reaction of CH₄, with N₂O at 773–823 K on a V₂O₅/SiO₂ catalyst affords products of the partial oxidation (HCHO and CH₃OH), exhaustive oxidation (CO), and oxidative condensation (C₂H₅OH and CH₃CHO) of methane. A mechanism is proposed for the complex reaction, including the intermediate compounds V⁵⁺O and V⁴⁺CH₃OH as common intermediates for all the routes.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 5, pp. 641–646, September–October, 1987.     

Mechanisms of Heterogeneous Processes in the System SiO2 + CH4: III. Products of >Si

Permenov  D. G.  Radzig  V. A. 《Kinetics and Catalysis》2004,45(2):273-278

Molecular and crystal structures of Ph2P(O)(CH2)2OH and Ph2P(O)CH2(C6H6)OH

The molecular and crystal structures of Ph₂P(O)(CH₂)₂OH and Ph₂P(O)CH₂(C₆H₆)OH have been determined. For the first compound the space group is with unit cell dimensions a=10.505(2), b=13.720(2), c=14.782(3) Å; =72.58(6), =76.95(6), =72.49(6)° for Z=6 (Syntex diffractometer,MoK radiation, 2996 reflections, R=3.2%). The second compound crystallizes in the space group P2₁2₁2₁ with unit cell dimensions a=9.371(3), b=9.014(3), c=18.461(5) Å for Z=4 (DAR-UM diffractometer,CuK radiation, 909 reflections, R=4.9%). In Ph₂P(O)(CH₂)₂OH, three independent molecules differing in structural details are linked by the P=O...O hydrogen bonds (O...H is 1.84, 1.80, and 1.86 Å), to form a chain. In Ph₂P(O)CH₂(C₆H₆)OH, the molecules are joined by pairs of the P=O...H–O bonds (O...H is 1.81 Å) to form 16-membered dimeric associates.Institute of Chemical Physics, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 34, No. 3, pp. 109–118, May–June 1993.Translated by T. Yudanova     

Temperature Dependence of Ligand Exchange in the Coordination Sphere of Tb(ClO4)3 · nH2O in the Presence of Adamantylideneadamantane-1,2-dioxetane and Benzophenone in Acetonitrile Solutions

The processes of complexation and solvation in the Tb(ClO₄)₃ · nH₂O –adamantylideneadamantane-1,2-dioxetane (I)–benzophenone (II) system in acetonitrile solutions were studied at 280–320 K. The complexation of Tb(ClO₄)₃ · nH₂O in ground and electronically excited states with I and II was found out. An anomalous increase in the lifetime of Tb(ClO₄)^* ₃ · nH₂O with temperature was observed; this anomalous increase is indicative of a structural change in the environment of the terbium ion in solution. It was found that of Tb(III)* increased because of rearrangement of the inner sphere of solvation aqua complexes toward the replacement of H₂O molecules by solvent molecules that exhibit a lower quenching ability.     

New water-soluble and film-forming aminocellulose tosylates as enzyme support matrices with Cu<Superscript>2+</Superscript>-chelating properties

Within the framework of our studies on enzyme-compatible support matrix structures, we succeeded in making further derivatives of the new aminocellulose type P–CH₂–NH–(X)–NH₂ (P = cellulose); (X) = –(CH₂)₂– (EDA), –(CH₂)₂–NH–(CH₂)₂– (DETA), –(CH₂)₃–NH–(CH₂)₃– (DPTA), –(CH₂)₂–NH–(CH₂)₂–NH–(CH₂)₂– (TETA) accessible by nucleophilic substitution reaction with ethylenediamine (EDA) and selected oligoamines starting from 6(2)-O-tosylcellulose tosylate (DS_tosylate = 0.8). The ¹³C-NMR data show that the EDA and oligoamine residues are at C6 of the anhydroglucose unit (AGU) and that OH and tosylate are also (partially) present at C6. OH and partially tosylate are at C2/C3. All the synthesized aminocellulose tosylates were soluble in water and formed transparent films from their solutions. The aminocellulose tosylate solutions and the films prepared from them formed blue-coloured chelate complexes with Cu²⁺ ions, whose absorption maxima at wavelengths in the VIS region were located similarly to those of the Cu²⁺ chelate complexes with EDA and with the oligoamines. AFM investigations have shown that the aminocellulose films, depending on structural and environment-induced factors influencing e.g. SiO₂ polymer films, exhibit flat topographies (<1 nm), and on protonated NH₂ polymer films, such as aminopropyl-functionalized polysiloxane films, nanostructured topographies of derivative-dependent shape and nanostructure size as film supports in the form of nanotubes. The aminocellulose films could be covalently coupled with glucose oxidase enzyme by various known and novel bifunctional reactions via NH₂-reactive compounds. In this connection, it was confirmed again that the immobilized enzyme parameters, such as enzyme activity/area and K_M value, can be changed by the interplay of aminocellulose film, coupling structure and enzyme protein in the sense of an application-relevant optimization.     

Raman Spectroscopic Study of Aluminum Silicate Complexes at 20°C in Basic Solutions

Raman spectroscopic measurements were performed at ambient temperature onaqueous silica-bearing solutions (0.005 < m _Si < 0.02; 0 < pH < 14). The spectraare consistent with the formation of monomeric Si(OH)^o ₄, SiO(OH)^– ₃ andSiO₂(OH)^2– ₂ species at acid to neutral, basic, and strongly basic pH, respectively.Raman spectra of aqueous Al-bearing solutions at basic pH confirm thepredominance of the Al(OH)^– ₄ species in a wide concentration range (0.01 < m _Al < 0.1).Raman spectra of basic solutions (12.4 < pH < 14.3), containing both Al andSi, exhibit a strong decrease in intensities of SiO(OH)^– ₃, SiO₂(OH)^2– ₂, andAl(OH)^– ₄ bands in comparison with Al-free Si-bearing and Si-free Al-bearingsolutions of the same metal concentration and pH, suggesting the formation ofsoluble Al—Si complexes. The amounts of complexed Al and Si derived fromthe measurements of the Al and Si band intensities in strongly basic solutions(pH 14) are consistent with the formation, between Al(OH)^– ₄ andSiO₂(OH)^2– ₂, of the single Al—Si dimer SiAlO₃(OH)^3– ₄ according to the reactionSiO₂(OH)^2– ₂ + Al(OH)^– ₄ SiAlO₃(OH)^3– ₄ + H₂OAt lower pH ( 12.5) the changes in band intensities are consistent with theformation of several, likely more polymerized, Al—Si complexes.     

Sila-Riechstoffe und Riechstoffe-Isostere. 11. Mitt. Vergleich von Carbinolen und Silanolen mit Thiocarbinolen und Silanthiolen

The thiocarbinolsRC(CH₃)₂SH withR=C₆H₅CH₂ and C₆H₅CH₂CH₂ were prepared via reactions 2–5 and compared in their odors (very unpleasant) with the fragrances of the analogous carbinolsRC(CH₃)₂OH and silanolsRSi(CH₃)₂OH. Silanethiols, prepared by reactions 6–8, smell less unpleasant than thiocarbinols but decompose easily in the presence of catalytic amounts of ammonium salts (eq. 9). Very pure hexenyl-methyl-vinylsilanethiol (silathiolinalool) decomposes contrarily under cyclization to a 1-sila-2-thia-cyclopentane derivative (E 1). The differences of odors, in spite of very similar structures, are discussed in the light of the theory ofAmoore (Size and structure of molecules rule their odor qualities).

Prof. DDDr. DDr. h. c.Viktor Gutmann zum 65. Geburtstag gewidmet.     

Mass-spectrometric study of physiologically active β-thiosemicarbazones of N-alkylisatins

The molecular ions of isatin (I) and N-methyl- (II) and N-ethylisatin (III) -thiosemicarbazones undergo fragmentation via many pathways with the elimination of NH₃, H₂S, CO, CH₂N₂, CHN₃, CH₂N₂S, CH₂NS, and CHNS particles; this is due to primary localization of the charge on the heteroatoms of the thiosemicarbazone residue. A previously unknown rearrangement, which consists in migration of an HS group to the -carhon atom of the heteroring with subsequent ejection of a CHN₃ fragment. The [M — CO]⁺ ions undergo fragmentation with the elimination of CH₂N₂S; in the case of II and III fragmentation is preceded by detachment of a hydrogen atom (II) or a methyl group (III) from the substituent attached to the ring nitrogen atom. The [M — CO, -H, -CH₂NS]⁺ (II) and [M — CO, -CH₃, -CH₂N₂S]⁺ (III) ions undergo fragmentation with the ejection of HCN in two ways through both the ring nitrogen atom and the thiosemicarbazone residue. Schemes for the principal pathways of fragmentation and rearrangements are presented. The compositions of the ions were confirmed by the high-resolution mass spectra and the mass spectra of the N-deuteroalkyl derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 75–79, January, 1979.     

Novel properties of molecular assemblies of isoprenoid surfactants

Unlike micelles of straight hydrocarbon chain-surfactants, isoprenoid surfactants, CH₃ [CH(CH₃)CH₂CH₂CH₂]₃ CH(CH₃)CH₂–R (R=CH₂N⁺ (CH₃)₃ Br^–, CH₂OPO₃H^– Na⁺, CH₂OSO ₃ ^– Na⁺, CO ₂ ^– Na⁺), gave large globular and cellular assemblies in water which could be observed directly by transmission electron microscopy; critical micelle concentration of 0.31.4×10^–3 M at 20°C, aggregation number of 215×10⁴, and diameter of 200–2000 Å. A basic structure of the assemblies was a thin layer with a thickness (about 30 Å) which was close to the molecular length of the surfactants. The assemblies were decomposed during gel column chromatography; viz., they were not as stable as the liposomes of lecithins. The morphology was discussed in conjunction with a steric effect of the isoprenoid chain.     

Infrared Spectra of Krypton Solutions of Methylamine

Variable temperature (–105 to –145°C) studies of the infrared spectra (3500–400 cm^–1) of methylamine, CH₃NH₂, dissolved in liquid krypton have been recorded. From these data, the hydrogen bonding enthalpy has been determined to be 530 ± 29 cm^–1 (6.34 ± 0.35 kJ/mol). The elusive ₁₃ and ₁₄ fundamentals, which are strongly mixed CH₃ rock and NH₂ twist, have been observed at 1244 and 876 cm^–1, respectively. These assignments are supported by frequency predictions from ab initio MP2/6-31G(d) calculations where the predicted infrared intensities for these two vibrations are 0.054 and 0.002 km/mol. The ab initio predicted infrared spectrum compares very favorably with that observed in the krypton solution. Normal coordinate calculations have also been carried out for four other isotopomers of methylamine, CH₃NHD, CH₃ND₂, CD₃NH₂, and CD₃ND₂ and vibrational assignments given from previously reported infrared spectra of matrix isolated samples. The Raman spectrum of these latter three isotopes, along with the normal species, have been predicted from MP2/6-31G(d) calculations and the results compared to the experimental spectra. The equilibrium structural parameters have been obtained from ab initio calculations utilizing several different basis sets with full electron correlation by the perturbation method to second order. These predicted values are compared to the previously reported experimental structural parameters.