Band 27, Heft 11

The nature and properties of radicals produced by the action of electron and γ-radiation on adamantane have been investigated. Radicals produced by irradiation at 77°K are stable to around room temperature, while irradiation at the latter temperature yields well resolved spectra of species stable to about 130°C. The significance of the latter, assigned as the 1-adamantyl radical, in the formation of trapped radicals is discussed.

Electrolytic lamellar compounds of graphite with well-defined oxidation stages were indicated by characteristic changes in the potential of a graphite anode during galvanostatic oxidation in nonaqueous, aprotic electrolytes. In analogy to the well-known graphite salts in acid media e. g. C 24 HSO 4 ·2 H 2 SO 4 1,2 a C n -stage with n = 24 besides others with n>24 was obtained in solutions of LiClO 4 , NaBF 4 or KPF 6 in propylene carbonate; further oxidation of graphite does not cause significat changes in the potential of the electrode. Such defined stages of oxidation were observed at graphite anodes in various nonaqueous electrolytes. According to the present results simple salt-like lamellar compounds of the general type C n X are proposed; contrary to graphite salts prepared in concentrated acids, intercalation of free electrolyte is not a matter of priciple.

The vibrational spectra of H 5 IO 6 and a number of periodates containing the anion IO 6 5- are reported and frequencies are assigned. The force constants of the IO 6 5- ion are interpreted on the basis of noticeable π bonding. The IO bonds in H 5 IO 6 are not all equivalent. As shown by their Raman spectra, solutions of H 5 IO 6 in concentrated strong acids contain the hexahydroxoiodine(VII) ion I (OH) 6 + with six equivalent IO bonds.

Bi(O 2 PCl 2 ) 3 ·POCl 3 , formed by the reaction of BiCl 3 and Cl 2 O in POCl 3 solution, has been characterised by vibrational spectroscopy. The Bi-atom is surrounded by the O-atoms of the chlorophosphate groups and the POCl 3 in a pseudo-hexahedral arrangement. The IR-spectrum of BiCl 3 in the 200—600 cm —1 region is reported.

The new compounds SrAl 2 Te 4 , SrGa 2 Te 4 , SrIn 2 Te 4 , BaAl 2 Te 4 , BaGa 2 Te 4 , BaIn 2 Te 4 , Ba 7 Al 6 Te 16 , NaInTe 2 and KInTe 2 have been prepared by melting together stoichiometric amounts of the elements. All compounds crystallize tetragonal in variants of the TlSe- (B 13) -structure. SrAl 2 Te 4 : α = 8.25 Å, c = 6.72 Å ( ± 0.02 Å) SrGa 2 Te 4 : α = 8.21 Å, c = 6.75 Å ( ± 0.02 Å) SrIn 2 Te 4 : α = 8.27 Å, c = 7.22 Å ( ± 0.02 Å) BaAl 2 Te 4 : α = 8.50 Å, c = 6.72 Å ( ± 0.02 Å) BaGa 2 Te 4 : α = 8.42 Å, c = 6.78 Å ( ± 0.02 Å) BaIn 2 Te 4 : α = 8.44 Å, c = 7.20 Å ( ± 0.02 Å) NaInTe 2 : α = 8.33 Å, c = 7.27 Å ( ± 0.02 A) KInTe 2 : α = 8.52 Å, c = 7.39 Å ( ± 0.02 A) Ba 7 Al 6 Te 16 : α = 34.24 Å, c = 6.70 Å ( ± 0.02 Å) (=4 × 8.57 Å),

The dipole moments of the complexes π (CH 2 CXCH 2 ) Fe (CO) (NO) L, with X and L equal, respectively, to H, CO; H, P (C 6 H 5 ) 3 ; CH 3 , CO; Cl, CO; Br, CO, have been measured. From the results it is concluded that: 1. The value of the group moment is ca. 1.6 D, if = 1.3 D and Co-Fe-CO(NO) =98°. 2. A trans structure appears most likely in the π (CH 2 CYCH 2 ) Fe (CO) 2 NO (Y = Cl, Br, CH 3 ). 3. Qualitative comparison between and group moments confirms that the C 5 H 5 group bonds to manganese as (C 5 H 5 ) δ- .

The stability constants of the ternary Cu 2+ complexes containing adenosine 5′-monophosphate (AMP) and as a second ligand, 2,2′-bipyridyl, 4- (2′-pyridyl) imidazole, 2-picolylamine, 4-aminomethylimidazole, and ethylenediamine were determined by potentiometric titration in water containing 10% dioxane (I=0.1; 25°C). For the equilibrium, Cu (amine) 2+ +Cu (AMP) ⇄Cu (amine) (AMP) +Cu 2+ , the corresponding constants are (in the order of the above amine ligands), Δ log K =log = 0.53 , 0.20 , 0.04 , —0.35 , and —0.45 ; hence , in the first cases the equilibrium is considerably on the side of the mixed-ligand complex. The importance of the π-system of the amine for the stability of the mixed-ligand Cu 2+ complexes is obvious from the given series. The imidazole group, an important binding site for metal ions in biological systems, has clearly qualities similar to the pyridyl group (Inorg. Chem. 9, 1238 [1970]), i. e. the stability of ternary Cu 2+ complexes containing these groups is increased.

A number of new complexes containing TRIPA, chemical formula [ (CH 3 ) 2 N] 2 P (O) N (CH 3 )P (O) [N (CH 3 ) 2 ] N (CH 3 ) P (O) [N (CH 3 ) 2 ] 2 , is reported The compounds have the general formula M (TRIPA) n (anion) p , where M = Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn, Cd (p = 2) and Al, Fe (p = 3), n=1,2 and anion stands for BF 4 ⁻, [B (C 6 H 5 ) 4 ]⁻, NO 3 ⁻ and Cl⁻. They are characterized and identified by chemical analysis and physical measurements. It is shown that the bis-compounds contain octahedrally solvated metal ions, the ligand acting as a tridentate phosphoryl donor. Electron paramagnetic resonance measurements show some distortion of the octahedrons. The mono-compounds with the nitrate anion probably possess a fivecoordinated structure whereas the chloride complexes are probably dimeric. The occurrence of more than one geometric isomer for the group [M (TRIPA) 2 ] P* is discussed. It is concluded that the s-facial and u-facial isomers may occur; a possible connection with the size of the metal ions is indicated. The mer form is rejected because of steric requirements.

Reactions of acetylacetonate-, salicylaldehydate- and methylsalicylate-metal compounds with oxygen, bromine and sulfurylchloride were investigated. It was found, that these reactions yield to a variety of products depending on the used central metal ion.

Atactic poly-4-vinylpyridine forms with transition metal compounds in ethyl alcohol the following complexes: Me (II) L 2 (P-4-VP-m) 2 and Me (II) J 2 (P-4-VP-m) 3 , Me = Fe, Co, Ni. L = Cl⁻, acetylacetonate, salicylaldehydate and o-nitrophenolate. The IR-spectra are discussed.

MoS 2 , WS 2 and TiS 2 react with K-naphthalid-solutions to intercalation compounds K x MeS 2 . Na- and Li-naphthalid reduce the sulfides to metal, but in the case of the sodium-compound the first step is intercalation to Na x WS 2 . Li-HMPT-solution reduces MoS 2 to Li x (HMPT) n MoS 2 and finally to Mo. The reasons for the differences in the reactive behaviour of the alkali-naphthalid-solutions are discussed.

The alkylations of aromatic compounds with trialkyl phosphites (1), dialkyl phosphites (2), and trialkyl phosphates (3) in the presence of aluminum chloride were studied involving several raction variables, such as time, ratio of reactants, nature of catalyst and solvent, and combinations thereof. Extensive disproportionation and isomerization were observed in the reaction with monosubstituted alkylbenzenes under heterogeneous reaction conditions obtained by the use of an excess of aromatic substrates. A combination of aluminum chloride—nitromethane complex and dichloromethane as solvent was used to eliminate these undesirable effects and to give homogeneous and practically non-isomerizing conditions. The scope of the reaction was studied with a number of aromatic substrates, and their relative reactivities were compared to that of benzene in competitive isopropylations with triisopropyl phosphite. The relative rates and isomer distributions showed low substrate and low positional selectivities and poor agreement with Brown’s selectivity relationship. The substrate selectivity was somewhat higher and the positional selectivities were somewhat lower than those obtained in competitive isopropylation reactions with other isopropylating agents. The selectivity factor, Sf, and partial rate factors were calculated. An electrophilic alkylation mechanism is proposed on the basis of (1) the relative rates of isopropylation, (2) the isomer distribution of dialkylated aromatics, and (3) the necessity of a strong Lewis acid in these reactions.

Extinction diagrams are applied for determining the number of partial reactions. In this paper a method is described for the calculation of the concentration of the reacting substances with the aid of extinction diagrams. The concentration values are more suitable for calculation of the rate constants, and in case of photochemical reactions the partial quantum yields, than the directly measured extinction values. The method of calculation is illustrated using the photochemical reaction of stilbene in a perfluorinated solvent as an example.

The reaction of anthraquinone in alkaline methanol irradiated with 313 nm light is followed spectrophotometrically. The experimental results point to an irreversible consecutive reaction A → B → C. Since the concentration and extinction coefficient of the intermediate are unknown, the partial quantum yield cannot be calculated. A new method is described for calculation of the concentration of the unknown intermediate using the extinction diagram. It is suitable for consecutive reactions, if the rate constant of the first reaction-step is very great as compared with that of the second. Now the partial quantum yields of the two reaction-steps can be calculated.

The Electron Spin Resonance study of 1,3,5,8-tetrahydroxy 2,7-dimethyl anthraquinone known as Nodosin has been carried out at room temperature and at X-band. The compound gives a norrow ESR line. The measurements of lineshape, linewidth and g-value have been made. A theoretical computation of dipolar width as well as narrowing due to exchange has been carried out with the help of KUBO and TOMITA theory and finally a value for J, the exchange coupling parameter has been estimated. On the basis of these measurements Nodosin has been proposed to adopt an intermediate structure.

The association of Schlen k’s hydrocarbon was studied by means of osmometric and magnetic measurements. The mixed chain-ring-association can be explained satisfactorily assuming that two different dimers and four monomer species participate in the equilibria, including a monomeric diamagnetic ring. The equilibria existing between the different species are discussed. For the equilibria between the monomer and dimer species, which can be detected in solutions of normal viscosity by means of ESR-measurements, the unexpected values of ΔH=0 for the enthalpie of association and ΔS= +19.7 e. u. for the entropie of association were found.

In vitro-studies show that the Ca-chelates of EDTA and DTPA are equally effective in removing Zn from the proteins and that the Zn-protein pool is composed of several fractions with different stabilities. Only a small fraction of the protein-bound Zn can be labelled by 65 Zn in vitro and, as to the mobilization of 65 Zn, Ca-DTPA was found to be 20 times more effective than equimolar Ca-EDTA. The isotope exchange between Zn-DTPA and protein-bound 65 Zn is an extremely fast reaction whereas in the case of Zn-EDTA a sluggish exchange takes place. The analysis of the results led to conclusion that the ligand and isotope exchange reactions in the case of EDTA proceed via the free Zn 2+ -ion; with the high-dentate DTPA, however, the formation of ternary and mixed complexes plays an important role. The implications of the findings as related to the toxicity of the Ca-chelates are discussed.

The reactions of ᴅ-amino acid oxidase with β-chloro-ᴅ-alanine and β-chloro-ʟ-alanine have been described. Both the holoenzyme and the apoenzyme catalyse the deamination of β-chloro-ʟ-alanine to keto acid without any consumption of oxygen or oxidation-reduction of the enzyme-bound FAD. The anaerobic reaction of the holoenzyme with β-chloro-ᴅ-alanine involves three phases with respect to the reduction of the enzyme-bound FAD, the rapid formation of an intermediate spectral species followed by a steady state of this intermediate and the last decay of the intermediate to the fully reduced enzyme. The rate of keto acid formation decreases as the reaction proceeds and ceases at the beginning of the conversion of the intermediate to the fully reduced enzyme. The aerobic reaction of the holoenzyme with β-chloro-ᴅ-alanine is biphasic. The first rapid oxygen consumption is followed by the second slow oxygen consumption. The second slow phase disappears by treating the enzyme with glutathione before the addition of substrate.

It is demonstrated that the 220—225 nm Cotton effect of 4-nitro imidazole nucleosides can be used for the determination of the configuration of this class of compounds. A more detailed picture about conformation and configuration of the sugar residue is received from the copperammonia complexes of these nucleosides. The pH-dependency of the stability and the complex ratio are discussed for a furanose moiety. Correlation between signs and intensities of the Cotton effects and configurations and conformations of the diol structures are discussed.

Viscometric technique has been used to estimate the relative contributions of strong and weak binding modes towards thermal stabilization of the Proflavine-DNA complex. Variation of the ratio of the specific viscosity of the dye-bound DNA to that of the DNA solution (η′ sp /η sp ) with different dye to DNA-phosphate ratios (D/P) shows that the saturation is attained at D/P value of about 0.2. This effect is more pronounced at lower ionic strengths. Heat-induced helix-coil transition curves at different D/P values at a fixed ionic strength of the buffer reveal a gradual shift towards higher temperature with the increase of D/P and levelling off at D/P of about 0.22. It is suggested that only the strong binding mode causes thermal stabilization of the DNA double helix and the double helix having all the possible intercalating sites saturated by the dye molecules attains the most stable configuration.

In the mycobiont of the lichen Lichina pygmaea mesosome-like structures are described which mainly occur in the fungi cells close to the algal layer. These structures consist of numerous irregularly arranged tubuli which are most distinct after fixation with glutaraldehyde at pH 7.0. Using different fixatives at varying pH they tend to visiculate. In the cytoplasm neighboured to the mesosome-like structures zones of very high contrast appear. They consist of a homogenous and a granular substance. Staining the samples with Best Carmin or treating them with amylase it could be shown that at least the granular component of the darkly stained area represents glycogen. The function of the mesosome-like structures in glycogen synthesis is discussed.

Concentrations of 0,8—90 μg α-amanitin per ml do not inhibit the growth of Agrobacterium tumefaciens in vitro. 20 ug/ml of the drug reduce tumor initiation by these bacteria (on leaves of Kalanchoe) if it is added simultaneously with the bacteria or 24 hours after infection. Addition of α-amanitin 96 hours after bacterial infection does not reduce the number of initiated tumors but it slows down tumor growth. These results demonstrate the participation in tumorigenesis of RNA synthesis in the nucleoplasm of the host cells.

An oxazine dye, Nile Blue sulfate, induces a fluorescent reaction in cytoplasmic granules (NBIFG) of living or fixed tumour cells in the same manner as reported before for Thiazine dyes. The NBIFG correspond to phase contrast positive granules when cells are viewed by phase contrast microscopy. Fluorescence disappears from NBIFG in a matter of 2—4 days and the bodies turn deep blue. These granules have a succinate dehydrogenase (SDG) activity and are negative for acid phosphatase, peroxidasic activity and porphyrin. The cytological findings support the assumption that Nile Blue sulfate forms a salt linkage with unsaturated fatty acids of NBIFG which also show an oxi-reductive activity. The molecular nature of the fluorophore (s) is (are) unknown.

Embryonic rat cells which have been stopped in G 1 -phase of their cell cycle by incubation in serum-free medium can be triggered by the addition of calf serum. Expamination of uridine uptake and RNA synthesis after stimulation gave the following results: 1) Uridine uptake into the acid soluble pool is increased within a few minutes. 2) 2 hours after the addition of serum cells incorporate twice as much 3 H-uridine into the acid insoluble material as do cells in serum-free medium; this is not the result of a higher rate of RNA synthesis but is due to an increased uridine uptake. As demonstrated by isolation of RNA and electrophoresis in polyacrylamide gels a significant de novo synthesis can be detected 4 hours after stimulation. Sedimentation coefficients of these RNA species are between 28S and 18S, and 18S and 4/5S, resp.; they turn over quite rapidly as was demonstrated by chase experiments. 3) When cells are grown for 2 hours in medium containing 3 H-uridine, little label can be detected in the ribosomal 18S- and 28S-RNA. Radioaktivity in these species is, however, strongly increased after another incubation period of 2 hours in culture medium without 3 H-uridine. This indicates that precursor molecules ars synthetized and subsequently degrated into 28S- and 18S-rRNA.

1. Under conditions of the endogenous respiration the mode of action of ethambutol on mycobacteria was studied. Oxygen uptake, 32 P-incorporation and changes in the phosphate-content were measured as parameters for the behaviour of the metabolism. 2. In order to localize the first step of inhibition the radioactive isotope was applicated in a fixed chronological order and a fractionation in acid-soluble fraction, polyphosphate-, RNA- and DNA-fraction was carried out. 3. Proportional to the incubation periode the 32 P was incorporated into the acid-soluble fraction, into the polyphosphate- and into the RNA-fraction in about the same proportions. The content in the DNA-fraction is nearly 200-times lower than in the RNA-fraction. 4. The main part of the phosphate is localized in the RNA (∼60%). Only in the begin of the incubation periode the part of the acid-soluble fraction is higher than that of the polyphosphate fraction. 5. The main part of the phosphate, transferred from the culture medium into the bacteries, was found in the polyphosphate fraction. During the incubation periode the phosphate-content in the RNA-fraction remains nearly unchanged. After decreasing to the begin the same was found for the acid-soluble fraction. 6. The specific activity of the polyphosphate fraction rises not continuously, according to the changes of the polyphosphate-content. Depending on the incubation periode the occured changes in the relations of the single fractions are similar in both the control- and the Ethambutol-trial. 7. In contrary to the results of other authors these investigations showed the same degree of inhibition of the phosphate metabolism in the acidsoluble fraction, the polyphosphate and the RNA-fraction. 8. Under conditions of the endogenous respiration ethambutol is inhibiting the phosphorylation of specific compounds of the intermediar-metabolism in the acid-soluble fraction or their further reactions. On the other side the changed incorporation of the 32 P can be explained with a alterated permeability of the cell wall of the bacteria.

The isoelectric behaviour of the NDV-induced rabbit serum interferon was compared with different NDV-induced interferons from rabbit cells. The activity of serum interferon was found in a pH range from 4.6—6.2. In contrast, the isoelectric positions of cell interferons could be demonstrated in a more acid pH range between pH 3.7 and 5.0.