Volume 28, Issue 1-2

The phase-diagrams of the systems AgCl-Ag 2 Se, AgCl-Ag 2 Te, AgBr-Ag 2 Se, AgBr-Ag 2 Te have been determined. Two peritectic compounds Ag 3 TeBr and Ag 5 Te 2 Cl were found. The liquidus curves were analyzed and entropies of melting of silverdialkogenides calculated.

Room-temperature 185 Re, 187 Re-NQR-spectra of polycrystalline perrhenates were measured. A dependence of the NQR-frequencies of the ± 5/2 ⇆ ± 3/2 ⇆ ± 1/2 transitions on nature and size of the cations in identical crystal structure was found.

The following alkaline earth halide hydrates could be found by differential thermal analysis: SrCl 2 · 6H 2 O, SrCl 2 · 2H 2 O, SrCl 2 · H 2 O; SrBr 2 · 6H 2 O, SrBr 2 · H 2 O; SrJ 2 · 6H 2 O, SrJ 2 · H 2 O; BaCl 2 · 2H 2 O, BaCl 2 · H 2 O; BaBr 2 · 2H 2 O, BaBr 2 · H 2 O; BaJ 2 · 6H 2 O, BaJ 2 · 2H 2 O, BaJ 2 · H 2 O. The dehydration temperatures increase with the size of the anions and decrease with the radius of the cations. The dehydration of SrCl 2 · H 2 O gives rise to two DTA-peaks, but there is no half-hydrate formed according to high-temperature IR-measurements. The X-ray data of Sr J 2 . H 2 O are communicated.

A polymer (CHS 2 ) n and sulfate are formed in the γ-irradiation of deaerated aqueous carbon disulfide solutions. The G-values are 3.6 and 0.41, respectively. In the presence of N,O, G (polymer) is decreased while G(SO 4 - ) is increased. G(SO 4 - ) can be decreased by isopropanol. G(polymer) is increased by H + ions and reaches a value of 5 below pH = 2. Formic acid, hydrogen sulfide and carbonate are formed in the hydrolysis of the polymer. Pyrolysis at first leads to a red oil consisting of oligomer (HCS 2 ) n and finally to H 2 S, CS 2 plus a residue containing much carbon. The structure of the polymer is discussed. Pulse radiolytic experiments show that CS 2 reacts with e aq (3.1 × 10 10 M -1 s -1 ) and OH(7.4 × 10 9 M -1 s -1 ) in a diffusion controlled manner. The first product of the reaction with OH is SC(OH)S. The pK of the electrolytic dissociation SC(OH)Ṣ ⇄ SC(O - )S + H + is 4.4. The absorption spectra of SC(OH)S and SC(O - )S were measured. SC(OH)S disappears by second order with 2k = 1.6 × 10 9 M -1 s -1 at pH = 6. The product is a bivalent acid, the spectrum of which was measured. The second pK of this acid is 5.7, its first pK is lower than 4. Both eāq and H react with CS 2 to form SCS - . The absorption spectrum of this radical anion was measured. The pK of the equilibrium SCSH ⇄SCS - + H + is about 1.6. In solutions of low H + -concentration, SCS - disappears by second order with 2k = 6.4 × 10 9 M -1 s -1 . The structure of dithioformic acid is attributed to the resulting product. In solutions of high H + -concentration, SCS - (or SCSH) disappears by a fast first order process, the rate constant of which increases with H + -concentration. The carbeniat neutralization is believed to be responsible for this process. The rate constant is 5.1 × 10 7 M -1 S -1 . The spectrum of SC(H)S was measured. This radical disappears by second order with 2k = 7.4 × 10 9 M -1 s -1 . The spectrum of the resulting product was also determined. It is concluded that the formation of the polymer and of SO 4 - occurs in processes in which the first products from the attack of eāq, H and OH on CS 2 as well as molecules which were built up from these products are involved.

Principal moments of some of the polyatomic single crystals such as ammonium dichromate, ammonium chromate, potassium chromate and potassium permanganate have been determined from room temperature down to liquid air temperature. These have been found to decrease with the decrease of temperature. This variation is smaller in magnitude. It has been observed that the temperature coefficient of the principal moments has almost the same value over the entire range of temperature. This small variation of paramagnetism has been attributed to the variation of absorption frequency in solid state.

Tl 2 S reacts with VS 2 2 to Τl 3 VS 4 and VS. With NbS 2 and TaS 2 the analogous thiometallates(V) are obtained. The metallic thallium hereby produced gives with NbS 2 and probably with TaS 2 an intercalation-phase Tl X Nb(Ta)S 2 . There is no reaction between Tl 2 S and MoS 2 up to 500°C. Thallium(I)-thiometallates(IV), Tl 2 MeS 3 , described in literature do not exist.

π-Allyltris(trifluorophosphine)cobaltcomplexes, C n H 2n-1 Co(PF 3 ) 3 , are synthetized by the reaction of hydrido-tetrakis(trifluorophosphine)cobalt with conjugated dienes. Suitable dienes are butadiene, isoprene, chloroprene, cis-1.3-pentadiene, trans-trans-2.4-hexadiene, 2.3-dimethyl-1.3-butadiene, 2.4-dimethyl-1.3-pentadiene and 1.3-cyclohexadiene. The complexes are thermally stable up to 100°C. They can be sublimed at 25°C/10 -3 Torr. They are extremely soluble in polar as well as in nonpolar organic solvents. Since the 1 H-NMR-signals are only poorly resolved, it is not possible to distinguish between expected isomers. The IR-spectra are consistent with a tetrahedral arrangement of the ligands.

The UV-irradiation of solutions of allyl jodide and allyl bromide, respectively, and Fe (PF 3 ) 5 yields π-allyl-tris(trifluorophosphine)-iron halides, π-C 3 H 5 Fe(PF 3 ) 3 X (X = J, Br). Otherwise, the analogous reaction with allyl chloride yields the diene complexe π-hexa-1.3-diene-tris(trifluorophosphine)-iron (O), π-C 6 H 10 Fe(PF 3 ) 3 . The compounds are characterised by their IR-, 1 H-NMR-and mass spectra.

Orange-red crystals of μ 3 -phosphido-nonakis(trifluorophosphine)-triiridium, PIr 3 (PF 3 ) 9 , are obtained by reductive fluorophosphination of IrCl 3 at 80-200 atm PF 3 -pressure. The structure of the new complex is proven by its mass spectrum, displaying a successive removal of nine PF 3 -groups. Rupture of the PIr 3 -cluster occurs only to an extremely small amount even with high energy electrons. UV-irradiation of HCo(PF 3 ) 4 and a mixture of HCo(PF 3 ) 4 with HIr(PF 3 ) 4 yields the bridged complexes (PF 3 ) 3 Co(H)(PF 2 )Co(PF 3 ) 3 and (PF 3 ) 3 Co(H)(PF 2 ) Ir(PF 3 ) 3 . The three complexes (PF 3 ) 4 M-M(PF 3 ) 4 (M = Co or Ir) with a direct metal-metal bond are not obtainable under these conditions. The mass spectra of all compounds and of Ir 2 (PF 3 ) 8 are discussed.

Various methods for the preparation of Trimethylsilylesters of Phosphinic acids R 2 P(X)YSi (CH 3 ) 3 (X, Y = O, S) are described. The properties and some reactions of these compounds are reported.

The direct reaction of MoO 3 and WO 3 with ethylenglycol and glycerol is reported. The prepared compounds were characterized by chemical analysis, IR-spectra and X-ray diffraction methods (powder and single cystal). Some chemical properties are given. All results indicate that the new compounds are derivatives of the hitherto unknown ortho-molybdic (VI) and tungstic (VI)-acids.

A series of complexes formed between transition metal ions and the stable free radicals 2,2,6,6- tetramethyl-4-amino-4-caboxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-aminopiperidine-l -oxyl, 2,2,6,6-tetram ethyl-piperidine-l-oxyl and glyoxal-bis(2,2,2,6,6-tetramethyl-4-iminopiperidine-1- oxyl) has been prepared. The magnetic moments and the epr-spectra of the complexes have been investigated. Some of the complexes show a temperature dependent interaction between the radicalic nitroxyl groups of the ligands. By analysis of the epr-spectra in the solid state there was found in some cases an interaction between the metal ion and the unpaired electrons of the ligands.

The 1 : 1 and 2 : 3 interactions of aluminium isopropoxide with bifunctional tridentate Schiff bases, derived by the condensation of o-hydroxyacetophenone with hydroxyalkylamines [such as 2-hydroxyethylamine, 2-hydroxy-1-propylamine, 1-hydroxy-2-methyl-2-propylamine and 1-hydroxy-2-butylamine] have been investigated. The resulting derivatives of the types, Al(OPrt)(SB) and Al 2 (SB) 3 (where SB 2 - is the anion of the corresponding Schiff base, SBH 2 ) have been isolated in almost quantitative yields. The ebullioscopic determination of molecular weights in benzene has shown the isopropoxy derivatives to be dimers, whereas the dialuminium-tris-Schiff base derivatives to be monomers. The infrared spectra of these compounds have been recorded and plausible structures indicated.

The syntheses of some p- substituted phenylcyclobutadieneirontricarbonyls are reported. Carbonyl stretching frequencies, 13 C-H- and H-Η-coupling constants are discussed with respect to bonding properties. There is apparently no conjugative interaction between the π-electron systems of cyclobutadiene and the phenyl ring.

The effect of the nucleic acid bases adenine, cytosine, thymine, uracil, and 5-bromo-uracil on the light-induced reduction of methylene blue in dimethylsulfoxide has been investigated by means of ESR and optical absorption studies. It could be shown that the nucleic acid bases act as electron acceptors. The experimentally obtained electron affinities are of the following order: cytosine > adenine > thymine ≈ uracil and confirm, thus, the theoretical predictions.

The preparation of 3-monoximes of different substituted acetoacetamides is described. The dissociation constants of these compounds and also the stability constants of their metal chelates were determined by potentiometric pH-measurements. The change of stability constants by the substituents of the amide group is interpreted.

The thermal decomposition of copper soaps has been studied both as a function of temperature and time. The whole range of the isothermal decomposition of copper soaps has been most adequately expressed by the Prout-Tompkins equation using two different rate constants.

At room temperature the chemical reaction between malonic acid (0.2 M) and KBrO 3 (0.06 м) in 1 м H 2 SO 4 is catalysed by cerium ions. The oscillation of the yellow Ce 4+ ions can be observed directly during the reaction. By silica-gel chromatography the brominated products of the reaction have been identified as dibromoacetic acid and bromomalonic acid.