Volume 60, Issue 12

Single crystals of light violet Nd 2 As 4 O 9 and yellow Sm 2 As 4 O 9 were obtained from the reactions of the respective lanthanide oxides with As 2 O 3 in a NaCl flux at 850 °C in sealed silica ampoules. According to the structure determination, the triclinic compounds (P1̅, Z = 2, Nd/Sm: a = 686.32(9)/680.92(9), b = 763.06(8)/756.4(1), c = 954.8(1)/951.2(1) pm, α = 96.83(1)°/96.66(2)°, β = 103.78(2)°/103.67(2)°, γ = 104.40(1)°/104.35(2)°, R1 = 0.0184/0.0282 (all data)) have to be formulated as RE 4 (As 2 O 5 ) 2 (As 4 O 8 ) emphasizing the presence of both As 2 O 5 4− and cyclic As 4 O 8 4− anions. The As4O 8 4− anions show C i symmetry and connect layers of the composition { 2 ∞ [RE 2 (As 2 O 5 )] 2 } 4+ along the [001] direction. The lanthanide ions are in nine- and eightfold coordination, respectively.

The title compounds were synthesized from potassium rich mixtures of Fe 2 O 3 , elemental potassium and the hyperoxide KO 2 by applying short reaction times, a maximum temperature of 875 K and subsequent quenching of the samples. The structures of the two new oxoferrates(III) have been determined by single crystal X-ray diffraction. The orthoferrate(III) K 5 [FeO 4 ] (Na 5 [GaO 4 ] structure type, space group Pbca, a = 1124,0(2), b = 667,95(9), c = 2034,8(3) pm, Z = 4, R1 = 0,0585) exhibits isolated ortho-anions [FeO 4 ] 5− with nearly ideal tetrahedral geometry and Fe-O distance in the narrow range of 189 to 192 pm. The pentaferrate K 17 [Fe 5 O 16 ] (space group Cm, a = 671,71(5), b=3560,8(3), c=670,81(5) pm, β =119,687(5)°, Z =2, R1=0,0291) crystallizes with a new structure type. Its building units are isolated novel penta-nuclear anions composed of five corner sharing [FeO 4 ] tetrahedra. These linear chain pieces [Fe 5 O 16 ] are arranged in a hexagonal rod packing, with a stacking sequence according to |:AB:| along the large monoclinic b axis. The structure is thus related to that of the tetra-ferrate K 14 [Fe 4 O 13 ] with a comparable packing of tetra-nuclear ferrate(III) anions.

A well-shaped sinoite crystal was milled out of a polished thin section of the Neuschwanstein (EL6) chondrite. The structure was refined on the basis of X-ray single crystal data:Cmc2 1 , a=885.66(18), b = 549.61(11), c = 484.23(10) pm, R1 = 0.0282, 491 F 2 values, 26 variable parameters. The structure consists of a complex three-dimensional network of corner-sharing SiN 3 O tetrahedra (Si-O 161.9, Si-N 171.9-172.8 pm). The crystal chemical peculiarities of Si 2 N 2 O are briefly discussed.

X-ray investigations have shown a complete miscibility in the systems TaS 2 /MoS 2 and TaSe 2 / MoSe 2 . In these systems mixed crystals could be obtained by chemical vapour transport with iodine as transport agent in the temperature gradient 1000→800 °C. By contrast, no mixed crystals are formed in the systems TiS 2 /MoS 2 and TiSe 2 /MoSe 2 . The transport behaviour in these systems is reported.

In the systems TiS 2 /NbS 2 , TiSe 2 /NbSe 2 , NbS 2 /TaS 2 und NbSe 2 /TaSe 2 complete miscibility in the solid state has been observed by powder X-ray investigations. Mixed crystals as well as the binary compounds can be prepared by chemical vapour transport reactions using iodine as transport agent in the temperature gradient 1000→900 °C. The gaseous species TiI 3 (g), TiI 4 (g), NbI 4 (g) and TaI 4 (g) are responsible for the transport effect.

The solvent-free title compound 2 ∞ [Fe II {H 3 N + CH 2 CH 2 C(OH)(PO 3 H − )(PO 3 H − )} 2 ] was prepared by hydrothermal synthesis and consists of (4,4)-nets of iron octahedra (as the nodes) linked by corner sharing tetrahedra of the phosphonate groups. These layers are stacked in an ABB’A’ sequence and are connected to give a three-dimensional network by hydrogen bonds between the non-Fe-bridging phosphonate groups. Pamidronate, C 3 H 10 NO 7 P 2 − is a zwitterion with an overall charge of −1.

The three quasi-binary phase systems BiOX-BiOY (X, Y = Cl, Br, I) have been investigated by X-ray powder methods. No quaternary phases were found in the three systems. BiOCl-BiOBr and BiOBr-BiOI form systems of unlimited mutual solubility. BiOCl-BiOI is a system of limited solubility at the iodine-rich side. In the BiOBr-BiOI system a strong deviation from Vegard’s rule is observed with respect to one of the lattice parameters. A few methods to quantify such a deviation are briefly discussed and a possible explanation for the strong deviation in the BiOBr-BiOI system is proposed. Error calculations have been performed to estimate uncertainties in the concentration parameter x of the investigated mixtures. The crystal structure of BiOI has been re-determined by single crystal structure analysis.

Sulfamethoxazole (5-methyl-3-isoxazolyl sulfanilamide) reacts with cadmium acetate in methanol in a steel autoclave at 150 °C to give crystalline [Cd(sulfamethoxazolato)2(CH 3 OH) 2 ] n· x(CH 3 OH) (1) the structure of which was characterized by single crystal X-ray diffraction. The triclinic crystals belong to the space group P1̅. In the polymeric assembly the Cd(II) centers are linked through sulfamethoxazolato anions which alternate in their coordination with the isoxazolic N-atoms and the aromatic amino groups. The chains of vicinal rings build tunnels along the crystallographic c axis.

The title compound has been synthesized by metathesis of Ba[Pt(CN) 4 ]·4 H 2 O with Rb 2 SO 4 , in aqueous solution. Its crystal structure was solved from X-ray powder diffraction data using the simulated-annealing approach, and refined by Rietveld’s method. The compound crystallizes in space group Imma, a = 11.1432(2), b = 7.4382(1), c = 11.1896(2) Å, V = 927.45(3) Å 3 , Z = 4, R p = 0.0402, R w = 0.0247 (N hkl = 173). Square-planar tetracyanoplatinate groups stack in an unprecedented eclipsed conformation, forming one-dimensional linear chains of Pt-atoms with Pt-Pt separations of 3.719 Å . Rb 2 [Pt(CN) 4 ] was characterized by differential thermal analysis, thermogravimetry and infrared spectroscopy.

In order to elucidate the interactions of copper with wood, three mononuclear copper( II) coordination compounds with a vanillinate anion, cis-[Cu(C 8 H 7 O 3 ) 2 (H 2 O) 2 ] (1), trans- [Cu(C 8 H 7 O 3 ) 2 (H 2 O) 2 ]·2H 2 O (2), and trans-[Cu(C 8 H 7 O 3 ) 2 (H 2 O) 2 ] (3), have been characterized. X-ray structure analysis of the cis isomer 1 reveals two bidentate vanillinate ions coordinated via methoxy (Cu−O1 2.260(2) Å ) and deprotonated hydroxy oxygen atoms (Cu−O2 1.909(2) Å ), and two water molecules (Cu−O1w 2.087(2) Å ) in the octahedral CuO 6 chromophore. Two axes O1−Cu−O1w’ in the octahedron have the same length, while the third axis O 2 −Cu−O 2 ’ is shorter. This is in agreement with the room temperature EPR spectrum of 1, showing two signals (g 12 2.302, g3 2.005), but interestingly, three signals (g 1 2.393, g 2 2.214, g 3 2.010) in the 115 K spectrum were found. The same coordination atoms were found also in the trans isomer 2 (Cu−O2 1.950(2), Cu−O1w 1.994(2), Cu−O1 2.334(2) Å ), however here, two axes of almost equal length are short (O2−Cu−O2’ O1w−Cu−O1w’), while the third axis is longer (O1−Cu−O1’). On the other hand, three (rhombic) signals (g 1 2.289, g 2 2.163, g 3 2.086) in the room temperature EPR spectrum of 2 suggest three different axes in the coordination octahedron. In the EPR spectrum, of the second trans complex 3, a slightly rhombically distorted elongated axial spectrum is found. The 115 K EPR spectra of the two trans complexes 2 and 3 do not differ significantly from the features observed at room temperature. These results indicate that there is not always a straightforward correlation between the results of XRD structure analysis and EPR spectroscopy. Nevertheless, both methods can act also complementarily and give a deeper insight into the nature of copper(II) chromophores.

Reactions of L-tert-Leucine (tert-butylglycine), tert-leucine methyl ester, GlyValOMe, and Leu- AlaOMe with the chloro-bridged complexes [Cp*IrCl 2 ] 2 , [(p-cymene)RuCl 2 ] 2 or [(C 6 Me 6 )RuCl 2 ] 2 in the presence of NaOMe give the complexes [Cp*Ir(Cl)NH 2 CH(R)CO 2 ] (1), [(p-cymene)Ru(Cl)- NH 2 CH(R)CO 2 ] (2), Cp*Ir(Cl 2 )[NH 2 CH(R)CO 2 Me] (5), {(C 6 Me 6 )Ru(Cl)[NH 2 CH 2 CONHCH(R)- CO 2 Me]} + Cl − (6), [Cp*Ir(Cl)NH 2 CH 2 CONCH(R)CO 2 Me] (7), [Cp*Ir(Cl)NH 2 CH(CH 2 CHMe 2 )- CONCH(R)CO 2 Me)] (8), and Cp*Ir(Cl 2 )[NH 2 CH 2 CONHCH(R)CO 2 Me) (9). With pentaglycine the complexes [Cp*Ir(Cl 2 )(pentaglycinate + Na + )] (10) and [(C 6 Me 6 )Ru(pentaglycineOMe- H + )] (11) could be isolated. Coordination of one equivalent of the S-protected tripeptide glutathione to [Cp*Ir(Cl)] and to [(C 6 Me 6 )Ru(Cl)] was observed. Some in situ prepared (p-cymene)Ru complexes with deprotonated dipeptide esters were tested as catalysts and the complex [(p-cymene)Ru(Cl)(NH 2 CH(CHMeEt)NCH (CHMe 2 )CO 2 tert-Bu)] gave a yield of 73% and moderate entantiomeric excess (36% ee) in the transfer hydrogenation of acetophenone to 2-propanol.

A new saponin trivially named leucioside (1) and a new triterpenoid along with two known lignans trachelosiaside (3) and matairesionol (4) C-glycosides, were isolated from the butanolic fraction of Trachelospermum lucidum. Compounds 1 and 4 showed potent inhibitory activity against lipoxygenase while compounds 2 and 3 showed moderate activity against lipoxygenase.

Two new mexicanolides, 3-deacetyl xyloccensin M and 3-deacetyl xyloccensin N were isolated from the fruit of the Chinese mangrove Xylocarpus granatum. Their structures were elucidated on the basis of modern spectroscopic techniques.

From the aerial parts of Phlomis tuberosa a new iridoid glucoside, chlorotuberoside was isolated together with five known iridoid glucosides, lamalbide, shanzhiside methyl ester, 7-epi-phlomiol (= phloyoside I), sesamoside and 5-deoxysesamoside. Two known phenylethanoid glycosides, forsythoside B, and decaffeoylacteoside, three known neolignan glycosides, dehydrodiconiferyl alcohol 9’-O-β -D-glucopyranoside, dihydrodehydrodiconiferyl alcohol 9-O-β -D-glucopyranoside and dihydrodehydrodiconiferyl alcohol 9’-O-β -D-glucopyranoside, one flavone glycoside, luteolin 7-O-β - D-glucopyranoside, as well as β -sitosterol 3-O-β -D-glucopyranoside and 1-methyl-O-β -D-glucopyranoside were also obtained and characterized. The structures of the isolates were elucidated on the basis of spectroscopic data. The three known phenylethanoid glycosides, verbascoside, leucosceptoside A and martynoside were identified by TLC comparison with authentic compounds.

Bromoarene carbaldehydes and bromoheteroarene carbaldehydes underwent a one-pot Suzuki cross coupling and Wittig olefination in aqueous medium to give compounds with extended π-systems.

The synthesis of a new biologically active cyclic pentapeptide, cyclonitroproctolin, cyclo(-Arg (NO 2 )-Tyr-Leu-Pro-Thr-) by solution phase synthesis is described. The structure of the synthetic peptide was characterized by IR, NMR, FAB mass and analytical data. The newly synthesized compound was screened for its antimicrobial and pharmacological activities.

Three biologically active cyclic peptides, viscumamide, yunnanin A and evolidine were synthesized and the structures were established on the basis of analytical, IR, NMR and mass spectral data. These newly synthesized cyclic peptides were evaluated for antimicrobial and pharmacological activities. Evolidine showed better growth inhibition against bacterial strains than yunnanin A and viscumamide. The anti-inflammatory activity of viscumamide is moderate and the remaining two cyclic peptides are found to be less active. But, all the three cyclic peptides showed weak anthelmintic activity.

R(Ph)Sb-Sb(Ph)R (1) [R = (Me 3 Si) 2 CH] is formed by reduction of Ph(R)SbCl with Mg. The meso-diastereomer of 1 has been characterised by X-ray crystallography. It adopts an antiperiplanar conformation in the solid state.