Volume 31, Issue 4

Bis(1,2-benzoquinonedioximato)-platinum iodide crystallizes in two modifications. Both consist of centrosymmetric Pt(BCD) 2 I 2 molecules, which are held together by intermolecular hydrogen bonds.

The new compound Sr 2 Cu 3 O 4 Cl 3 was prepared in melts of SrCl 2 . A single crystal X-ray examination (a = 546.2, c =1259.1 pm, space group D 17 4h -I 4/mmm) shows that the octahedral distortion of the [Cu 3 O 4 Cl 2 ] 4- -network cannot be explained only by the JAHN-TELLER effect.

Dark-brown Ca 2 AsBr and yellow-green Ca 3 AsBr 3 were prepared by reaction of Ca, As, and CaBr 2 at 900-1000°C and 760-800°C resp., dark-violet Sr 2 AsCl from Sr, As, and SrCl 2 at 900-1000°C. Ca 2 AsBr possesses an extended homogeneity range (Ca 2 AsBr to Ca 2.5 AsBr 2 ), Sr 2 AsCl only a narrow one; Ca 3 AsBr 3 is a stoichiometric compound. In contrary to Ca 2 AsBr Ca 3 AsBr 3 is not stable at 1000°C. Analytical results, densities, and lattice constants of the phases are given.

Raman EPR and visible absorption spectra of sodium tetrasulfide in the solid state and melts have been studied from room temperature up to 300°C. The above techniques provide strong evidence for breaking of the polysulfide chains resulting in the production of S 3 -radical ions. The existence of the radical ions in polysulfides at elevated temperatures is important for understanding the electrode processes in sodium sulfur batteries.

The Raman, IR and FIR spectra of polycrystalline samples of the polysulfides Na 2 S 4 , K 2 S 5 , Na 2 S 5 have been measured. A unique assignment of the internal vibrations of the tetrasulfide ion could be achieved.

Preparation and properties of the title compound are described. The mechanism of formation is suggested in part. IR, Raman and NMR spectra are given and interpreted. The X-ray structural analysis is reported and structural features are discussed.

The oxidation of the substituted ethylenes, 2,3-dimethylbutene-2 (1), 2-methylbutene-2 (8), and α-methylstyrene (18), by ferriin or lead dioxide in water and/or methanol has been studied. Product analyses of the reactions, which lead to kinetically controlled product distributions, showed that lead dioxide, just as ferriin, reacts as a one-electron-oxidant. The product distributions, which arise from further reactions of the primary intermediates, i. e. the radical cations formed via one-electron transfer, were found to depend on substituents, acidity and solvent. The results are consistent with three separate reaction paths of the radical cation, each of which leads to specific products. The radical cation can either deprotonate, be nucleophilicly attacked by solvent, or lead to dimeric products. The first two possibilities only are observed in the oxidation of 1 and 8, while only the latter two are found in the oxidation of 18.

Vinylaryldithiophosphinic acids RR′P(S)SH (R = vinyl; R′ = p-methoxyphenyl, p-ethoxyphenyl) were obtained as NH 4 -salts from the reaction of aryldithiophosphonic anhydride with CH 2 =CHMgBr. Alkali hydrolysis of the methylester RR′P(S)SCH 3 (R′ = p-methoxyphenyl) gave β-methylnercaptoethyl-p-methoxyphenylthiophosphinic acid.

Preparation and properties of several metal vinylaryldithiophosphinates (CH 2 =CH)RPS 2 M/n (R: p-methoxyphenyl; p-ethoxyphenyl) are reported. Copolymerisation of the ammonium salt (CH 2 =CH)RP(S)SNH 4 (R = p- ethoxyphenyl) with methacrylic methylester gave polymers (M∼10,000) which acted as polyfunctional ligands thus giving soluble polymeric metal complexes (M ∼17,000) with Ni(II) and Co(II).

Complexes formed between manganese(II) and the ligands Gly-Tyr, Gly-Phe, Ala-Ala, Tyr, cysteine and cystine have been prepared. The IR, EPR spectra and the magnetic moments of the compounds have been collected. Oxidation of the dipeptide complexes in solution leads to manganese(III) species.

Reaction of (C 6 H 5 CN) 2 PdCl 2 and 1,3-dimethylenecyclohexane led to an exocyclic π-enyl complex of formula (C 8 H 13 PdCl) 2 -bis(η 3 -2-methylene-6-methylcyclohexyl)(di-µ-chloro)-dipalladium. IR and 1 H NMR data are in agreement with this formulation. The compound is monoclinic, with unit cell dimensions α = 499.97 ± 0.08, b =1342.26 ± 0.19, c =1379.60 ± 0.20 pm, β = 99.43 ± 0.02°, space group C 5h 2 -P2 1 /C, Ζ = 2, d X-ray = 1.83 g/cm 3 . The structure was determined from three-dimensional X-ray data by Patterson and Fourier methods. Least squares refinement by use of 1045 independent reflections has reached R 1 = 5.6%.

The mass spectra of six symmetrically (R′=R) and three unsymmetrically (R′≠R) substituted dialkylthiolsulfonates have been determined. With the exception of the diethyl derivative the base peak is derived from direct fission of the sulfinyl S-R bond. Fission of the S-S bond with rearrangement and rearrangement of the alkyl residue are two further processes of importance enabling characterisation of the species.

In the present paper the mechanism and kinetics of methane-water mixtures decomposition in cold plasma are discussed. It was found that nature and composition of the products depend on reaction time, ratio of the two components, and how long the products are in contact after the decomposition was performed. Reactions in the decomposition system generally follow two mechanisms: corresponding to the discharge phase and to postreaction one. The highest yield of formaldehyde was obtained for the ratio methane water of 0.6-1 and two minutes of discharge.

1 H NMR spectral data of 2-diphenylamino-[1,3,2]oxathiaarsolane are presented and discussed. The protons of the CH 2 -groups form an AKPX-spin system. The vicinal H-C-C-H coupling constants indicate a twist-envelope conformation. A rapid inversion at arsenic does not take place.

This paper presents the results of investigations of the melting diagrams for the systems durene/SbCl 3 , pentamethylbenzene/SbCl 3 , hexamethylbenzene/SbCl 3 , diphenyl/SbCl 3 , naphthalene/SbCl 3 , 2,3-dimethylnaphthalene/SbCl 3 , phenanthrene/SbCl 3 and anthracene/SbCl 3 ; in all cases solid complexes with the composition ArH · 2 SbCl 3 were formed.

The exchange of chlorine between 1,2,3,3-tetrachloro-1-propene (1) and SbCl 3 occurs only on C-1 and C-3 of 1. A law of 1. order discribes the exchange. A mechanism with the 1,2,3-trichloropropenylium ion (10) is in accordance with these facts. Investigations on cis/trans isomerization of 1 in systems with AlCl 3 and SbCl 3 and 1 H NMR studies give informations about the concentrations of 10.

Following Zimmermann’s method of correlating intensity tensors from single crystal Mössbauer spectra with electric field gradient (EFG) tensors we are able to derive a manyfold of solutions for the orientation of the principal axis system of the local EFG with respect to the heme coordinate system in deoxymyoglobin. Comparing these results with theoretical estimates of the asymmetry parameter η we are able to limit the range of possible orientations of , and we find V ẑẑ to be rather close to the heme plane with a deviation from that of at most 14°.

Treatment of salicylidene-anils with potassium cyanide in acetic acid affords 1:1 adducts shown to be the hydrocyano derivatives. When the reaction is conducted in alcohol, salicylidene derivatives of 2-amino-3-arylaminobenzofurans or α-arylamino-o-hydroxyphenylacetamides are formed depending on the molar ratio of the reactants. The formation of the products and the previously reported structures are discussed.

Condensation of β-aminocrotononitrile (2 a) with 4-hydroxycoumarin (1 a, X = O, R = R 2 = H, R 1 = OH) afforded the tricyclic compound 7 and the bicyclic compound 11a from 4-hydroxy-6-methyl-2-pyrone (4). Analogous compounds could not be obtained from 4-hydroxy-6-methyl-2-pyridone (5) or 4-hydroxycarbostyril (6) due to the failure of the resulting condensation products 12a and 13, respectively to undergo intramolecular cyclization. The structures assigned to 7, 11a, 12a, 18, as well as to 5-cyano-4,6-dimethyl-2-pyridone (14), obtained by self-condensation of β-aminocrotononitrile, were substantiated by spectroscopic studies.

N → O Benzyl group migration upon pyrolysis of the zwitterionic pyrido-pyrimidine (4) leads to the uncharged O-ether (3) in poor yield. On the other hand, heating of the monocyclic mesoionic pyrimidine (12) gives a radicalic N →C migration of the benzyl group yielding the 5,5-dibenzyl-4,6-dioxo-pyrimidine (14).

4,6-Diphenyl-, 6-phenyl-4-p-tolyl- and 6-styryl-4-phenyl-3-thioxo-5-oxo-2,3,4,5-tetrahydro-1,2,4-triazines (1 a-c) react with tetra-0-acetyl-α-D-glucopyranosyl bromide (2) to give the corresponding 2-tetra-0-acetyl-B-D-glucopyranosyl derivatives (4a-c), respectively. Oxidation of 4a with H 2 O 2 gives the 3,5-dioxo derivative (7). On the other hand deacetylation of 4a affords 2-B-D-glucopyranosyl-4,6-diphenyl-3-thioxo-5-oxo-2,3,4,5-tetrahydro-1,2,4-triazine (8). Furfurylidene pyruvic acid condenses with 4-phenylthiosemicarbazide to give 6-furfurylidene-4-phenyl-3-thioxo-5-oxo-2, 3, 4, 5-tetrahydro-1, 2, 4-triazine (1d). 1d reacts with ethyl iodide to give the 3-ethylmercapto derivative (9), and reacts with 2 to give 4d.

The 1 H NMR spectra of quinazoline-disulfide (8) and some known quinazolines (8, 7a, 7b) were analyzed by the combination of spin decoupling experiments and simultaneous addition of Eu(fod) 3 . Under the assumption of an independent 1:1-complex formation of both quinazoline-nitrogens with the shift reagent (i.e. the 1: 2-complex concentration is negligible) there exists a linear dependence between the chemical shift of different protons within one compound. The slopes of corresponding protons of 8 differ from those of 3, 7a, 7b due to steric effects.

The combined action of orthoformate and aniline upon 4-hydroxy-coumarin yields anilinomethylene chromon-2,4-dione, which reacts with ethyl cyanoacetate in DMF in the presence of KOH to give the pyronocoumarine (6a). Pyronoquinolones are obtained in a similar way.

Single crystals of Sr 2 Si have been prepared. From a complete X-ray structure determination follows the anti-PbCl 2 structure type.

Upon use of a synthetic method reported earlier by us respective alloys of Na/Sn, Na/Ge and Na/Sb are dissolved in ethylenediamine and the title compounds precipitated from the solutions in high yield. By recrystallisation well shaped, stable crystals are obtained. The crystal structure of [Na 4 · 7 en]Sn 9 confirms the presence of a Sn 9 4-- -polyhedron which had been suggested by us on the basis of other investigations. The Sn 9 4- -polyhedron may be described as a distorted tricapped trigonal prism. Ethylenediamine is coordinated to Na + -ions exclusively.

Exchange of one cyclopentadienylring in different ferrocenes by tetra- or dimethylthiophene gives cationic thiophenecyclopentadienyl-iron(II)-complexes, which were characterized spectroscopically.

The ternary compounds Au 2 As 2 Te 3 , AuSbTe und AuSb 0,077 Te 2 have been found. Melting point or peritectic temperature as well as microhardness and X-ray diagramm have been measured.

Cs 2 [Pt(CN) 4 ] · H 2 O is hexagonal with lattice constants α 0 = 9.687(2) and c 0 = 19.336(6) Å; the probable space groups are C 6 2 -P6 1 or C 6 3 -P6 5 . The observed density yielded 3.67(4) g/cm 3 and the calculated one 3.697 g/cm 3 for two formula units per unit cell. X-ray powder data are given. The [Pt(CN)4] 2- groups do not lie one above the other but form a helix along the c-axis.

γ-Thiovalerolactone (1), under high pressure (15 kbar, 170°C), forms the compounds 2 and 3. Under similar conditions, δ-thiovalerolactone polymerizes nearly quantitatively; at 11 kbar and 170°C, 5 is formed in 2% yield. Thiooxindole 7 reacts to yield 8 and the thermically very stable trimer 9.

Diphenyldiazomethane reacts with triphenylborane to yield benzophenonazine and benzophenone triphenylmethylhydrazone. The formation of the latter is elucidated by ESR spectroscopic detection of the triphenylmethyl radical. The reaction can be modified to a simple method for the preparation of triphenylmethyl radicals in high yields.

The reaction of harmaline with the cyclohexanone derivative (4) affords the reserpine analogue (5) in high yields, thus providing a one step approach to such pharmacologically important substances.