Volume 62, Issue 1

A new potassium molybdenum oxide, K 6 Mo 10 O 33 , was synthesized by solid state reaction from the appropriate quantities of pre-dried MoO 3 and K 2 MoO 4 , fired at around 650 °C for 2 d. The structure has been solved by using single crystal X-ray diffraction. The compound adopts the space group P1, with the lattice constants a = 7.7100(5), b = 11.9659(8), c = 17.1321(12) A° , α = 86.42 (10), β = 77.18(10), γ = 74.14(10)°. The structure is built up of infinite chains of edge-sharing MoO 6 octahedra and groups of four MoO 6 octahedra forming Mo 4 O 17 units. These sub-units are connected together by common vertices.

Eu 5 Sn 3 S 12 and Eu 4 LuSn 3 S 12 were synthesized and their structures refined from single crystal data (Pmc2 1 , Eu 5 Sn 3 S 12 : a = 3.908(1), b = 20.115(4), c = 11.451(2) Å ; wR2 = 0.0519 for 3048 F 2 and 122 parameters; Eu 4 LuSn 3 S 12 : a = 3.920(1), b = 20.132(4), c = 11.459(2) Å ; wR2 = 0.0737 for 3298 F 2 and 122 parameters). The structures contain one-dimensional chains of edge-sharing SnS 2 S 4/2 octahedra and corner-sharing SnS3S2/2 trigonal bipyramids, running parallel to [100]. Five europium sites are seven- or eightfold coordinated by sulfur atoms. Lutetium atoms in Eu 4 LuSn 3 S 12 show a strong site preference for one of the two Eu 3+ positions of Eu 5 Sn 3 S 12 and no structural disorder was observed. Both compounds show static mixed valence according to Eu 2+ 3 Eu 3+ 2 Sn 4+ 3 S 2− 12 and Eu 2+ 3 Eu 3+ Lu 3+ Sn 4+ 3 S 2− 12 , which was confirmed by temperature dependent magnetic susceptibility measurements. The experimental magnetic moments of 14.6(1) (Eu 5 Sn 3 S 12 ) and 14.1(1) (Eu 4 LuSn 3 S 12 ) μ B /f.u. indicate that each of the two sulfides contains three divalent europium atoms per formula unit. Magnetic ordering for Eu 5 Sn 3 S 12 and Eu 4 LuSn 3 S 12 sets in below 5 and 3 K, respectively. Both sulfides show metamagnetic or spin-flip transitions in the magnetization curves at 3 K (2 K) with full saturation of the europium magnetic moments at 3 K (2 K) and 80 kOe. 151 Eu Mössbauer spectra fully confirm the Eu 2+ and Eu 3+ site occupancies. At 4.2 K an increase in line width indicates small hyperfine fields at the europium nuclei.

Single crystals of the ternary copper(I) lanthanide(III) sulfides with the composition CuMS 2 (M = Dy - Lu) are formed within seven days at 750 °C by oxidation of elemental copper and lanthanide metal with sulfur (molar ratio: 1 : 1 : 2, evacuated silica tubes) in equimolar quantities of CsCl, CsBr or CsI as fluxing agents. The CuYS 2 -type crystal structures (orthorhombic, Pnma, Z = 4; e. g. CuDyS 2 : a = 1342.51(9), b = 397.96(3), c = 627.43(5) pm and CuLuS 2 : a = 1315.06(9), b = 391.04(3), c = 624.18(5) pm) exhibit chains of cis edge-linked [CuS 4 ] 7− tetrahedra with the composition 1 ∞ {[Cu(S1) 3/3 (S2) 1/1 ] 3− } which run parallel to [010] and show hexagonal rod packing. Charge compensation and three-dimensional interconnection of these anionic strands occur via octahedrally coordinated M 3+ cations surrounded by six S 2− anions. These [MS 6 ] 9− octahedra share vertices and edges to form a three-dimensional network 3 ∞ {[M(S1) 3/3 (S2) 3/3 ] − } with the ramsdellite-type topology of γ-MnO 2 . The metal sulfur distances within the [MS 6 ] polyhedra are very similar (M-S: 263 - 279 pm), whereas those within the [CuS 4 ] units cover the ranges 227 - 230 (Cu-S 2 ) and 231 - 233 (Cu-S1) as well as 250 - 252 pm (Cu-S1′, 2×). The present work is the first comprehensive X-ray single crystal diffraction study of the complete isotypic B-type series CuMS 2 (M = Dy - Lu).

Single crystals of the isotypic hydrides Ba 2 H 3 X (X = Cl or Br) were obtained by solid-state reactions of Ba, NaCl, NaNH 2 and metallic Na, or Ba, NH4Br and Na, respectively, in sealed, silicajacketed stainless-steel ampoules. The crystal structures of the new compounds were determined by means of single crystal X-ray diffraction. Ba 2 H 3 Cl and Ba 2 H 3 Br crystallize in a stuffed anti CdI 2 structure and adopt the space group P3̄m1 (No. 164) with the lattice parameters a = 443.00(6), c = 723.00(14) pm and a = 444.92(4), c = 754.48(14) pm, respectively. The hydride positions are derived by crystallographic reasoning and with the help of EUTAX calculations. The results are compared with known data for binary and ternary alkaline earth metal hydrides.

Five isostructural bis(dibenzyldimethylammonium) tetrachlorometallate solvate complexes [M = Mn(II), Co(II), Ni(II) or Zn(II)] were crystallized from acetonitrile and/or methanol solutions. The crystal structures are compared to those of the analogous, isostructural copper compounds (X = Cl or Br) reported earlier. The complexes crystallize in the monoclinic space group P2 1 /n with Z = 4, and unit cell dimensions of a ≈ 14.1, b ≈ 16.1, c ≈ 15.7 °A and β ≈ 108 - 109°. The asymmetric unit of these compounds contains one MCl 4 2− anion, two Bz 2 Me 2 N + cations in theW-conformation and one half of a disordered solvent molecule (acetonitrile or methanol). The geometry of the MCl 4 2− anion is close to tetrahedral, whereas the analogous copper anions appeared in distorted tetrahedral geometries with trans angles of 124.4° for X = Cl and 123.6° for X = Br. In addition to the ionic interactions between the cations and the anions, the components are connected by weak C-H· · · Cl − bonds. As a distinction between the two crystallographically independent cations in the asymmetric unit, one type of independent cations form long chains via weak edge to face π-π interactions along the crystallographic b axis, whereas the other type of cations are not tied together by such weak π-π interactions. The coordination around the N atoms is also nearly tetrahedral, and neither static nor dynamic disorder of the Bz 2 Me 2 N + cations can be observed. The complexes are thermally stable and melt close to the decomposition temperatures in the range 170 - 205 °C.

Six new A 2 MBr 4 structures [A = dibenzyldimethylammonium cation,M = Mn(II), Co(II) or Zn(II)] were crystallized with or without solvent molecules from acetonitrile, methanol and/or aqueous solutions. The isomorphous compounds [(Bz 2 Me 2 N) 2 ][MnBr 4 ]·CH 3 CN·H 2 O (1) and [(Bz 2 Me 2 N) 2 ]-[ZnBr 4 ]·CH 3 CN·H 2 O (4) crystallize in the triclinic space group P1̄ from acetonitrile solutions. The solvent molecules participate in the hydrogen bonding network inside the crystal structure. [(Bz 2 Me 2 N) 2 ][CoBr 4 ]·0.5CH 3 CN (2) crystallizes from an acetonitrile solution in the monoclinic space group P2 1 /c. The solvent molecules fill the voids of the crystal structure. Compound 2 is isostructural with the previously reported compounds [(Bz 2 Me 2 N) 2 ][MCl 4 ]·0.5CH 3 CN with M = Mn(II), Co(II), Ni(II), Cu(II) or Zn(II). [(Bz 2 Me 2 N) 2 ][CoBr 4 ] (3) and [(Bz 2 Me 2 N) 2 ][ZnBr 4 ] (5a) crystallize from a methanol solution in the monoclinic space group P2 1 /c without solvents. A polymorph of compound 5a, [(Bz 2 Me 2 N) 2 ][ZnBr 4 ] (5b), was crystallized from aqueous solution in the monoclinic space group P2 1 /c. The packing of the components of the two polymorphs differs clearly. One cation of 5a appears in the W-conformation whereas the other cation of 5a and both cations of 5b appear in twisted conformations. In addition to the ionic interactions between the ion pairs, the packing of the compounds is stabilized by hydrogen bonds and weak intermolecular π-π interactions in all cases. The compounds melt around 200 °C and decompose mainly in two steps just above the melting point. Slow evaporation of solvents is observed both in the TG and DSC diagrams of the solvates (1, 2 and 4) below 100 °C.

Bis(allylammonium)pentachloroantimonate(III) - allylammonium chloride, (C 3 H 5 NH 3 ) 2 [SbCl 5 ] · (C 3 H 5 NH 3 )Cl, belongs to the chloroantimonate(III) organic-inorganic salts family. The DSC studies of this compound showed two anomalies at 181 K and at 223 K. Both are associated with phase transitions, which mainly occur due to ordering-disordering processes of the organic cations. Between 181 and 223 K the structure is incommensurate. The crystal structure was determined at 298 and 86 K. At both temperatures the crystal structure consists of (C 3 H 5 NH 3 ) + cations, anionic distorted [Sb 2 Cl 10 ] 4− units and isolated Cl − ions. In the room-temperature phase two out of three, and in the low-temperature phase two out of six allylammonium cations were found to be disordered. The deformations of the [Sb 2 Cl 10 ] 4− moieties in both phases are discussed and explained by the deviation of the Sb III 5s electron lone pair from its spherical symmetry and the influence of N-H···Cl hydrogen bonds, which join together the organic and inorganic sublattices.

A dinuclear dysprosium(III) p-fluorobenzoate 1,10-phenanthroline complex, [Dy(p-FBA) 3 phen] 2 was synthesized and characterized by elemental analysis, UV and IR spectroscopy, single crystal X-ray diffraction, molar conductance, and TG-DTG techniques. It crystallizes in the triclinic space group P1̄ with a = 9.895(5), b = 11.754(6), c = 14.756(10)Å ; α = 106.660(9)°, β = 107.956(9)°, γ =101.472(7)°; Z =1. The Dy(III) ions are eight coordinate including one terminal bidentate chelating carboxylate group, four bridging carboxylate groups and one 1,10-phenanthroline molecule. The thermal decomposition of [Dy(p-FBA) 3 phen] 2 has been followed by thermal analysis. The lifetime equation at weight-loss of 10% was deduced as lnτ = −27.0798 +19010.2434/T by isothermal thermogravimetric analysis.

The tripod phosphane ligand FSi(CH 2 CH 2 PMe 2 ) 3 (1) has been prepared again and attempts to generate F 3 CSi(CH 2 CH 2 PMe 2 ) 3 (2) were undertaken for the preparation of transition metal cage compounds of the type A(CCP) 3 M or A(CCP) 3 M-L (A = FSi, F 3 CSi). The photochemical addition of dimethylphosphane to trifluoromethyl-trivinylsilane, however, gave 1 instead of the expected CF 3 Sitripod ligand 2, obviously due to difluorocarbene elimination. 1 was used to prepare the chromium carbonyl derivative (CO) 3 Cr[(Me 2 PCH 2 CH 2 ) 3 SiF] (3) from Cr(CO) 3 CHT, and 3 was characterized by NMR and IR spectroscopy. The novel complex FSi(CH 2 CH 2 PMe 2 ) 3 Pd (4) and its PPh 3 derivative [FSi(CH 2 CH 2 PMe 2 ) 3 Pd]PPh 3 (5) have been obtained by reacting 1 with Pd(PPh3)4 and were characterized by NMR (4) and X-ray diffraction (5). The data prove the expected Pd→Si interaction by characteristic coordination shifts and a Pd-Si distance of 3.875 Å which is smaller than the Ni-Si distance in the corresponding nickel compound (3.92 Å ). The preparation of the analogous platinum complex from the precursors Pt(PPh 3 ) 4 , Pt(C 7 H 10 ) 3 , or (Ph 3 P) 2 Pt(η 2 -C 2 H 4 ) failed, whereas the reaction of 1 with Pt(PEt 3 ) 4 was successful, but surprisingly led to the trinuclear complex [FSi(CH 2 CH 2 PMe 2 ) 3 Pt] 3 (PMe 2 CH 2 CH 2 ) 3 SiF (6) with three cages of type 4 and an additional ligand 1 as a bridging unit. Complex 6 was isolated and characterized spectroscopically. Quantum chemical calculations have been used to elucidate the coordination geometry expected for 4, 5 and the corresponding platinum cage 4′ in 6. The calculations support the structure of 5 within the expected limitations of the experimental and theoretical methods and - in spite of the extremely soft coordination sphere of the studied cages - are in accord with the spectroscopic results.

2,5-Diformylbenzene-1,4-diol (5) is a well-suited starting compound for the preparation of ditopic hydroquinone-based ligands. Here, we report an optimized synthesis of 5 which improves the overall yield from published 7% to 42 %. Three new ditopic Schiff base ligands, 2,5-[ i Pr 2 N(CH 2 ) 2 N=CH] 2 - 1,4-(OH) 2 -C 6 H 2 (8), 2,5-(pyCH 2 N=CH) 2 -1,4-(OH) 2 -C 6 H 2 (9), and 2,5-[py(CH 2 ) 2 N=CH] 2 -1,4- (OH) 2 -C 6 H 2 (10), have been synthesized from 5 and structurally characterized by X-ray crystal structure analysis (py = 2-pyridyl).

The 1,2-hydroboration of various alkyn-1-yl(chloro)silanes (3 - 7), derived from 1-hexyne (a) and ethynylbenzene (b), using 9-borabicyclo[3.3.1]nonane, 9-BBN, affords selectively alkene derivatives in which the dialkylboryl and chlorosilyl groups are in geminal positions at the C=C bond. The molecular structure of (Z)-α-(9-borabicyclo[3.3.1]non-9-yl)-α-dichloro(phenyl)silyl-styrene (11b) was determined by X-ray diffraction. All alkenes were characterised by a consistent set of NMR spectroscopic data ( 1 H, 11 B, 13 C, 29 Si NMR).

Lipase-mediated monoacetylation of 6,7-dihydroxytropinones 4 gave acetates 5, ent-5 which were analyzed as Mosher esters 9a, b by 1 H NMR spectroscopy. However, the hydroxy groups in 4 were not differentiated by lipases. Reduction of the keto function and subsequent silylation afforded a mixture of endo/exo-TBS ethers 11, which were dihydroxylated to give the corresponding diols endo/exo-12. In chemical acetylation a change of the endo/exo ratio in favor of the endo-derivative endo-13 was observed, whereas the formation of the exo-acetate exo-13 dominated in lipase-catalyzed acylation reactions. A mechanistic proposal is given.

Reactions of 5-phenyl-3(3H)-thioxo-1,2,4-dithiazole (1) with unsaturated and active phosphonium salts as well as with phosphonates, at r. t. and under the effect of basic catalysis, afforded mainly 1,3,5- dithiazines 5, 12, 17a, 17b, 23a or 23b. Substituted 1,3-dithiol 7 and 1,3-thiazoles 13, 19a, 19b, 22a and 22b were isolated as by-products. 1,3,5-Dithiazine products showed pharmacological potency.

1,3-Diisopropyl-4,5-dimethylimidazolium 2-nitrodiethylmalonate (2) was obtained from 2,3- dihydro-1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (1) and 2-nitrodiethylmalonate; its crystal structure reveals the presence of interionic bifurcated C-H· · ·O hydrogen bonds.

The reaction of 6-aminouracil (1) with the appropriate α,β -unsaturated ketones, gave the corresponding pyrido[2,3-d]pyrimidin-2,4-diones 3, 6, 8 and 10, respectively. Treatment of 1 with salicylaldehyde, 6-carboethoxy-3,5-diphenyl-2-cyclohexenone (13) or 2,6- bis(phenylmethylidene)cyclohexanone (15) afforded the corresponding pyrimido[4,5-d]quinoline- 2,4-diones 12, 14 and 16, respectively. Furthermore, a pyrido[2,3-d]pyrimidine incorporating 3,2’- bis(quinoline) derivative 18 was synthesized. Annulation of pyrido[2,3-d]pyrimidine with pyrazole or imidazole moieties was achieved via reaction of 1 with benzylidene derivatives of pyrazolone, imidazolone or 3-carboethoxycoumarin (23) to give 21, 22 and 24, respectively.

The reaction of 3,4-dihydroisoquinolin-1-yl-acetonitrile with DMFDMA afforded the enaminonitrile 5. Compound 5 was reacted with 2-aminobenzimidazole to yield 4-amino-3-(dihydroisoquinolin- 1-yl)-benzo[4,5]imidazo[1,2-a]pyrimidine (11) and with acetonitrile derivatives to afford pyrido[2,1- a]isoquinolines (15a - g).

The asymmetric synthesis of the new lignan cubebin dimethyl ether was accomplished in eight steps with an overall yield of 40 %. In addition, the known lignans (+)-hinokinin and (+)-dihydrocubebin were synthesized by this route. Our approach involves the highly diastereoselective and enantioselective (de ≥ 98%, ee ≥ 98%) construction of a trans-substituted 2,3- dibenzylbutyrolactone through an asymmetric Michael addition of an enantiopure lithiated aminonitrile to 5H-furan-2-one.

The aerial part of Thymus cilicicus Linn. (Labiatae) has afforded two new hydroxy chalcone derivatives, characterized as 4, 2′, 4′, 6′, 7, 8-hexahydroxy-7 (8)-dihydro-chalcone (1), and 3, 4, 2′, 4′, 6′, 7, 8-heptahydroxy-7 (8)-dihydro-chalcone (2). The structures of the isolated compounds have been elucidated based on various spectral studies.

A new natural nor-sesquiterpene was isolated from the leaves of Jasonia montana, in addition to another rare nor-sesquiterpene. Their structures were established by spectroscopic methods, including 1 H, 13 C, DEPT, 1 H- 1 H COSY, HMQC, HMBC, NOESY, IR and HR-MS.

The North American stalked puffball Calostoma cinnabarinum (Boletales) owes its red-orange colour to the heptaene pigment calostomal. Its structure has been determined by 1 H and 13 C NMR spectroscopy of the corresponding methyl ester as all-trans-16-oxohexadeca-2,4,6,8,10,12,14- heptaenoic acid (1). Neither pulvinic acids nor other typical Boletales pigments could be detected in this fungus. The structural relationship of 1 to other polyene pigments from fungi is discussed.

The new sesquiterpenoid 8-deoxy-15-(3′-hydroxy-2′-methyl-propanoyl)-lactucin 3′-sulfate (1) was isolated from the methanolic extract of roots of Reichardia gaditana L. The compound was isolated by silica gel column chromatography (CC) and repeated Sephadex LH-20 CC. Structure elucidation was accomplished by high-resolution mass spectrometry and by 1D- and 2D-NMR spectroscopy. The chemosystematic significance of the new compound is discussed in the context of sesquiterpenoids from other members of the Lactuceae tribe of the Asteraceae family.

Extensive chromatographic purification of the alkaloid fraction of Aconitum vulparia Rchb. led to the isolation of a new norditerpene alkaloid, vulparine (1), besides the known compounds septentriodine (2), finetiadine (3), anthranoyllycoctonine (4), N-methyl-N-deethyllycoctonine (5) and delectinine (6). The structure of the new compound was determined by means of HRMS, 1D and 2D NMR spectroscopy. Detailed NMR studies, including 1 H- 1 H COSY, NOESY, HSQC and HMBC experiments, resulted in complete and unambiguous 1 H chemical shift assignments for 2 and 6, and revision of some 13 C NMR data. Compounds 1 - 4 were evaluated for their cytotoxic activities, and 1, 3 and 4 were found to exhibit marginal cell growth inhibitory activity against breast adenocarcinoma (MCF-7) and cervix adenocarcinoma (HeLa) cells.