Volume 42, Issue 11

Structural investigations on PrCl 3 were performed from room temperature down to 40 K (powder) and from room temperature down to 83 K (single crystal). Special interest was focussed on the changes of the coordination geometry of the Pr 3+ -ion.

Tetranuclear clusters Mo 4 S 4 (R 2 PS 2 ) 6 (4) (a: R = Et, b: R = Pr) with cubane-like cores are conveniently obtained by reacting equimolar quantities of Mo 3 S 4 (Et 2 PS 2 ) 4, Mo(CO) 6 and R 2 P(S)-S-S-P(S)R 2 . 31 P NMR and MS data of 4 are reported and the magnetic properties are discussed. 4a crystallizes triclinically with a = 1159.41(6), b = 1162.77(7), c = 2228.54(14) pm, α = 102.660(3), β = 98.382(4), γ = 98.546(5)°. P1̅, Z = 2. The molecule consists of a distorted Mo 4 S 4 cubane. Each Mo atom is coordinated by six S atoms: three within the cubane, two from a bidentate and one from a chelating dithiophosphinato ligand. Two Mo -Mo distances are short- ened by the chelate to an av. of 278.6 pm, while the av. of the remaining four Mo -Mo distances is 287.9 pm.

The ionic conductivities (complex impedance measurements) of the olivine type Li 2 ZnCl 4 , Na 2 ZnCl 4 and Na 2 CoCl 4 , the Sr 2 PbO 4 type Na 2 MgCl 4 , Na 2 MnCl 4 , and Na 2 CdCl 4 , and the novel Na 2 CrCl 4 with monoclinically distorted Sr 2 PbO 4 structure (Na 2 CuF 4 type) are presented. The specific conductivities of Li2ZnCl4 and the Na2MCl4 are about three orders of magnitude lower than those of the fast ionic conducting lithium chloride spinels Li[LiM ]Cl 4 (M = Mg, Mn. Fe. Cd. etc.) indicating that in the latter compounds the tetrahedrally coordinated lithium ions exhibit higher mobility than those on octahedral sites. The X-ray data including those of Sr 2 PbO 4 type Na 2 TiCl 4 and both the IR and Raman spectra (together with a group theoretical treatment) are also given. The spectra obtained confirm the different structure types of the ternary chlorides.

The reaction of [H 2 NPPh 2 NPPh 2 NH 2 ]Cl (1) with WClft (2) proceeds with formation of (3) and HCl 5 N 6 P 4 Ph 8 W 2 (4). 3 is the main product of this reaction. 4 was characterized by an X-ray structure determination. 4 contains a seven and a six-membered phosphorus-nitrogen ring with a W-W bond of 269.2 pm.

The reaction of LW(CO) 3 (L = 1,4,7-triazacyclononane) with Br 2 in CHCl 3 yields orange [LW(CO) 3 Br](Br 3 ) which was converted to its BF 4 - salt. [LW(CO) 3 Br]BF 4 crystallizes in the triclinic space group P1̅ (a = 8.273(3), b = 8.628(2), c = 13.034(3) Å , α = 80.10(2), β = 72.69(2), γ = 61.14(2)°, Z = 2); it consists of cations [LW(CO) 3 Br] + , with seven-coordinate W atoms, and BF 4 - anions. The corresponding salt [LW(CO) 3 F](PF 6 ) was obtained from LW(CO) 3 with 20% aqueous HF in the presence of air and addition of NaPF 6 . The analogous reaction with 37% aqueous HCl affords green crystals of [LW(CO) 3 H] 2 [WOCl 5 ]·H 2 O which crystallize in the monoclinic space group P2 1 /c (a = 12.234(4), b = 18.853(7), c = 14.609(5) Å, β = 105.65(3)°, Z = 4). The W atoms in the [LW(CO) 3 H] + cations are seven-coordinate; the six-coordinate [WOCl 5 ] 2- anions are not disordered. The W = O distance is short (1.72(1) Å ), the mean equatorial W-Cl distance is 2.390 Å whereas the W-Cl bond distance trans to the W = O group is 2.562(5) Å.

MoF 4 (NCl) has been prepared as a yellow crystal powder by the reaction of diluted fluorine with MoCl 3 (N 3 S 2 ) at room temperature. The compound is associated via fluorine bridges, according to the IR spectrum. With acetonitrile, the monomeric complex [CH 3 CN -MoF 4 (NCl)] is obtained, which was characterized by its IR and 19 F NMR spectra as well as by an X-ray structure determination. Crystal data: space group Pm, Z = 2 (1068 observed, independent reflexions, R = 0.03). Lattice dimensions at -90 °C: a = 507.1. b = 704.8, c = 995.8 pm, β = 102.02°. The unit cell contains two crystallographically independent molecules [CH 3 CN -MoF 4 (NCl)], the Mo≡N-Cl groups being linear (bond angles 176°, 178°) with bond lengths MoN = 172 and NCI = 159, 162 pm. In the trans position to the MoNCl group, the nitrogen atom of the acetonitrile molecule is coordinated.

The crystal structures of the triclinic compounds Cu 3 V 2 F 12 · 12H 2 O (a = 750.8. b = 760.7, c = 812.2 pm, α = 91.01, β = 89.80, γ = 92.84°; Z = 1), Cu 3 Cr 2 F 12 · 12H 2 O and Cu 3 Fe 2 F 12 · 12H 2 O with similar cell parameters, were refined in space group P1̅ to R factors of 0.03 and less. The structure consists of planar tetraquo cations [Cu(H 2 O) 4 ] 2+ (average Cu-O = 196.3 pm), which become elongated octahedra by sharing fluoride ligands of [MF 6 ] 3- anions at greater distances (av. Cu-F = 231.5 pm). The resulting three-dimensional framework of corner-sharing (distorted) octahedra contains large cavities, in which another [MF 6 ] 3- anion is inserted and fixed by hydrogen bonds. The arrangement of complex ions corresponds to an anti-perovskite structure AMX 3 = [MF 6 ][MF 6 ][Cu(H 2 O) 4 ] 3 . The variation of distances within the octahedra (mean values V-F = 194.3, Cr-F = 191.1 and Fe-F = 193.7 pm) is discussed in connection with the length of the hydrogen bridges O-H···F (average 270 pm and 168°).

A transition metal induced C-C coupling by the reaction of W 2 (N(CH 3 ) 2 ) 6 , (4) and CS 2 yielded the zwitter ion S 2 C-C(N(CH 3 ) 2 ) 2 (1d) besides W 2 (N(CH 3 ) 2 ) 2 (CS 2 ) 2 S 4 (5). The com- plex chemistry of the zwitter ions 1d and S 2 CC(N(CH 2 ) 4 X) 2 (X = CH 2 , O) has been investigated by their reaction with (η 5 -C 5 H 5 ) 2 Mo 2 (CO) 4 (2) and (η 5 -C 5 H 5 )Mo(CO) 3 Cl (3). Reaction of the former led to complexes (η 5 -C 5 H 5 )Mo(CO) 2 (S 2 CR) (R = N(CH 3 ) 2 , N(CH 2 ) 4 X) and the new compounds [(η 5 -C 5 H 5 )Mo(CO) 2 (S 2 C-CR 2 )] + . X-ray structure analyses of 1d and ((η 5 -C 5 H 5 )Mo(CO) 2 (S 2 C-C(N(CH 2 ) 5 ) 2 )] ⊕ PF 6 ⊖ (10b) are described.

The complete analysis of the 1 H, 13 C, 15 N NMR spectra of iminopyrophthalone demonstrates that the solution structure of the molecule must be described as a protonated iminocompound. 13 C-CP/MAS spectroscopy proves that the solid state structure of α-PPH and IPH are equivalent to the solution structure.

A large series of metal carbonyl complexes with N -bonded anions of various cyclic imidates (X - ) has been prepared: [M(CO) 5 X] - , [M(CO) 4 (PPh 3 )X ] , [M(CO) 3 (en)X] - (M = Cr, Mo, W), Re(CO) 5 X , [π-CH 3 C 5 H 4 Mn(CO) 2 X] - , [Mn(CO) 4 X 2 ] - . Also pyromellitdiimidate and cyclopentanebis(dicarboximidate) bridged complexes [(OC) 5 MXM(CO) 5 ] 2- (M = Cr, Mo, W) and the dicyanamide complex [π-(C 5 H 5 )Mn(CO) 2 NCNCN] - have been obtained. Reactions at the coordinated imidate ligands and the spectroscopic data of the complexes are reported.

Mößbauer spectra of mono and dinuclear iron carbonyl complexes of three cyclic diazenes and the crystal structures of two products formed from (cis-diazene)Fe 2 (CO) 6 and alkynes are reported. The ring size of the diazene ligand influences the stereochemistry of the cycloadducts obtained in the latter reaction; the bicyclic diazaferracycloalkene skeleton of these compounds leads to an exo- and endo-arrangement of one iron carbonyl group relative to the five- and six- membered diazene, rcspectively.

Reaction of Cp 2 Ti(CO) 2 , Cp=h 5 -C 5 H 5 , with the 1,2-diazenes ROCN = NCOR (R = EtO (1a), tert-BuO (1b), p-MeC 6 H 4 O (1c), p-MeC 6 H 4 (1d)) in the molar ratio of 1:1 yiclds five- membered metallacycles 2 by formal 1,4-addition of 1 to the Cp 2 Ti fragment. When a two-fold excess of Cp 2 Ti(CO) 2 is employed, the initially formed 2 reacts further by N = N-cleavage to give Cp 2 Ti(NCO)(OR), Cp 2 Ti(NCO) 2 and Cp 2 Ti(OR) 2 resp., in the case of 1a-1c. The bis(p-methyl- benzoyI)diazene (1d) does not afford analogous cleavage products. Dimethyl- and pentamethy- lenediazirine also react by cleavage of the N = N-bond to afford Cp 2 Ti(NCO)(N=CR 2 ).

Mixed ligand complexes of the type Ni(ROCS 2 )HDz) have been prepared, where R = methyl, ethyl, propyl, butyl and cyclohexyl, and HDz = dithizonate anion. These complexes were identified on the basis of spectroscopic measurements (IR, UV-VIS and NMR), magnetic moment values, thermogravimetric analysis, and analytical data. The results permit assignment of a tetrahedral structure for these complexes.

We synthesized a varicty of colloidal and non-colloidal mixed hexacyanoferrate(II) complexes of Fe. Cu. Co. Ni. Zn. Mn and studied ihe cesium Sorption in vitro under physiological conditions (artificial gastric juice. pH 1.2 and artificial duodenal juice. pH 6.8). All of the hexaeyanoferrates under study (except cesium iron(III) hexaeyanoferrate CsFeHCF) sorb tracer amounls of 13 Cs quantitatively. Differences in the sorption capacity become obvious by offering substantial amounts of cesium. Potassium copper hexacyanoferrate(II) (KCuHCF) and potassium zinc hexa- cyanoferrate(II) (KZnHCF) are most efficient in cesium sorption at pH 1.2 and at pH 6.8. The sorption capacities of KCuHCF and KZnHCF (2.3-3.0 mmol Cs'g HCF) are twice as high as for coiloidai Prussian blue (KFeHCF; 1.0-1.3 mmol Cs/g HCF) and insoluble Prussian blue (FeHCF: 1.0-1.6 mmol Cs/g HCF). The most promising Compounds. KCuHCF and KZnHCF. should be further investigated in in vivo studies for 137 |l4cesium decorporation. Evidence indicate that the sorption mechanism for most of the Compounds under study is a cesium/potassium ion-exehange reaction. In the case of insoluble Prussian blue (FeHCF). a cesium/proton exchange was observed. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ On laboratory scale. 137 |V4Cs-contaminated whey dry powder. produced from South German cow milk in summer 1986 was almost completely decontaminated by dialysing a whey Suspension against buffer Solution containing FeHCF. The 117 "JCs'-ions. completely bound by FeHCF. can be isolatcd from the buffer Solution by simple filtration. The buffer Solution and the FeHCF can We synthesized a variety of colloidal and non-colloidal mixed hexacyanoferrate(II) complexes of Fe, Cu, Co, Ni, Zn, Mn and studied the cesium sorption in vitro under physiological conditions (artificial gastric juice. pH 1.2 and artificial duoden al juice. pH 6.8). All of the hexacyanoferrates under study (except cesium iron (III) hexacyanoferrate CsFeHCF) sorb tracer am ounts of 137 Cs quantitatively. Differences in the sorption capacity become obvious by offering substantial amounts of cesium . Potassium copper hexacyanoferrate(II) (KCuHCF) and potassium zinc hexacy an o ferrate(II) (KZnHCF) are most efficient in cesium sorption at pH 1.2 and at pH 6.8. The sorption capacities of KCuHCF and KZnHCF (2.3 -3.0 mmol Cs/g HCF) are twice as high as for colloidal Prussian blue (KFeHCF; 1.0-1.3 mmol Cs/g HCF) and insoluble Prussian blue (FeHCF; 1.0-1.6 mmol Cs/g HCF). The most promising compounds, KCuHCF and KZnHCF , should be further investigated in invivo studies for 137/134 cesium decorporation. Evidence indicate that the sorption mechanism for most of the compounds under study is a cesium /potassium ion-exchange reaction. In the case of insoluble Prussian blue (FeHCF), a cesium /proton exchange was observed. On laboratory scale, 137/134 Cs-contaminated whey dry powder, produced from South German cow milk in summer 1986 was almost completely decontaminated by dialysing a whey suspension against buffer solution containing FeHCF. The 137/134 Cs + -ions, completely bound by FeHCF can be isolated from the buffer solution by simple filtration. The buffer solution and the FeHCF can be re-used several times.

Treatment of methyl 4,6-O-benzylidene-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside with sodium cyanoborohydride/hydrogen chloride gives rise to a very convenient approach of 1,5-anhydro-6-O-benzyl-2,3-dideoxy-D-erythro-hex-2-enitol (2), envisaged to be a precursor for both α-D- and β-L-glycosyl compounds in the pentopyranosyl series. An X-ray analysis revealed 2 to be of space group P2 1 and to adopt an O H 5 -conformation.

Complete amino acid sequences of lion (Panthera leo) hemoglobins are reported. Polyacrylamide gel disc electrophoresis at pH 8.3 and also in the presence of 8 M urea and Triton-X100, RP-HPLC, liquid and gas phase amino acid sequenator. and FAB Mass spectrometer are used. Sequences are aligned with human hemoglobin (Hb A ) and compared with other hemoglobins of felidae.

Administration of [2- 14 C]mevalonolactone to excised leaves of Acnistus breviflorus produced labelled withaferin A and jaborosalactone A. Degradation of the labelled withanolides allowed isolation of C-26, and in the case of withaferin A of C-1, both derived from C-2 of mevalonolactone. The relative specific activity of these carbon atoms was consistent with our previous results indicating the partial cleavage of the side chain of a sterol precursor in the biosynthetic process leading to the withanolides.

From the latex of Euphorbia biglandulosa Desf. the cerebrosides 1-O-β-D-glucopyranosyl- 2-N-2′-hydroxy-cis-15-tetracosenoyl-4-hydroxy-eicosasphinga-as-10-enine (1), 1-O-β-D-glucopyranosyl- 2-N-2′-hydroxy-cis-17-hexacosenoyl-4-hydroxy-eicosasphinga-cis-10-enine (2) and 1-O-β-D-glucopyranosyl-2-N-2′-hydroxy-4-hydroxy-eicosasphinga-cis-10-enine (3) were isolated. Structures have been elucidated by 1 H NMR , 13 C NMR . MS spectroscopy, hydrolysis, and ozonolysis, too.

GMF was isolated from the glia of different brain parts of calf. Its influence on the input of 3H-TdR was tested in leukaemic and non-malignant lymphocites. GMF isolated from the diencephalon proved to be the most effective one. The used substance of reference was DBcAMP. The cAMP contents of leukaemic cells were lower than those of non-malignant cells, whereas the level of cGMP was higher in the first ones. We found both in non-malignant cultures and in cultures of leukaemic cells that the impact of GMF and AdF elevated the cAMP value and reduced cGMP. The adhesion of cAMP to the nuclei of leukaemic was reduced in comparison with non-malignant cells. The nuclei of leukaemic cells showed increased adhesive capacity after pre-incubation with GMF and AdF. The adhesive capacity of non-malignant nuclei remained unchanged. The adenylcyclase activity (AC) was diminished in leukaemic cells. It could not be stimulated by means of catecholamines. GMF and AdF produced a slight increase of the basal Ac activity in cultures of leukaemic cells only. But isoproterenol led to a distinct increase of the Ac activity in leukaemic cells when incubation with those two factors preceded it.

In a photochemical decomposition reaction of the a-Diazoketone 1 in the presence of toluene ring-opening of the adjacent furanoyl substituent occurs as well as conversion of a norcaradiene intermediate thus forming the acetylenic olefinic aldehyde 4 and the dihydrobenzofuran 3. Reaction pathways are derived from the corresponding ketocarbeneoxirene equilibrium in which surprisingly the secondary ketocarbene B-1 gives rise to the formation of the aldehyde 4! No Wolff rearrangement product could be detected.