Volume 61, Issue 2

UCl 3 type La(OH) 2 I can be stabilized by additional water molecules during a hydrothermal synthesis from hydroiodic acid and lanthanum carbonate hydrate at 453 K to form La(OH) 2 I(H 2 O). The new rare earth (RE) hydroxide halide hydrate crystallizes monoclinically, space group C2/m with lattice parameters of a = 19.691(3), b = 4.136(1), c = 6.286(1) Å, β = 108.45(1)° and V = 485.6(2) Å 3 , wR2 = 0.0695, 648 F 2 values and 32 variables. La centered, distorted, tricapped, trigonal prisms formed by iodide, (OH − )- and (H 2 O) groups are connected via common edges in [001]-direction and common faces in [010]-direction to built up a zigzag like layered arrangement. Hydrogen bonding between the water molecules and iodide ions of adjacent La(OH) 2 I layers stabilize the UCl 3 related structure, which was only observed for the lighter homologues La(OH) 2 X (X = Cl, Br) so far. DTA/TG and IR measurements substantiated the occurrence of (H 2 O)- and (OH − )-groups and semiquantitative EDX analyses proved a 1:1 composition for La:I in La(OH) 2 I(H 2 O).

2,7-Diselenatricyclo[6.2.0.0 3.6 ]deca-1,3-diene-4,5,9,10-tetraone, C 8 O 4 Se 2 , was prepared from 1,2-diselenosquarate and squaric acid dichloride. Its crystal structure and the structure of the already known sulfur analogue C 8 O 4 S 2 were determined (C 8 O 4 S 2 : orthorhombic, Pca2 1 , a = 1413.64(2), b = 599.850(9), c = 968.8(1) pm; C 8 O 4 Se 2 : orthorhombic, Pnnm, a = 415.46(2), b = 894.29(5), c = 1160.14(7) pm). The structures are not isotypic and show a different packing of the molecules whose symmetry deviate only slightly from D 2h . In the four-membered C 4 rings the C-C bonds represent one single bond, one double bond and two slightly shortened single bonds. The C 4 rings are thus to be considered as cyclobutene-dione fragments. The vigorous exothermic decomposition of the compounds that occurs on heating to 220 to 240 °C shows that both are energetic materials. The explosions are accompanied by a heat evolution of −192 kJ/mol for C 8 O 4 S 2 and −224 kJ/mol for C 8 O 4 Se 2 . Performing the decomposition of C 8 O 4 S 2 in a closed autoclave leaves a residue of the composition “C 6 S” which was examined by transmission electron microscopy techniques and shown to consist mainly of amorphous carbon. This thermal behaviour is limiting the utilization of C 8 O 4 S 2 and C 8 O 4 Se 2 as precursors for the syntheses of OC 3 S and the yet unknown OC 3 Se via FVP. The formation of OC 3 S could be proven by the reaction of the trapped, slightly yellow product (evaporation at 200 °C, pyrolysis at 500 °C, trapping at −196 °C) with aniline which yielded thiomalonic acid dianilide, of which the crystal structure was determined (monoclinic, C2/c, a = 2814.8(16), b = 1201.7(8), c = 809.2(4) pm, β = 91.88(4)°, V = 2736(3) ・ 10 6 pm 3 ). The mass spectrum of C 8 O 4 Se 2 shows the strongest signal for OC 3 Se+, and FVP experiments (evaporation at 220 °C, pyrolysis at 650 °C, trapping at −75 °C) yielded small amounts of a bright yellow material which rapidly converted into a black polymer.

The crystal structure of the newly synthesized complex, trans-aqua-bis(benzylamino)-bis(5,5-dimethylhydantoinato) copper(II) was determined by X-Ray single crystal data. The thermal analyses, FT-IR and magnetic susceptibility data are also presented. The complex crystallizes in the monoclinic system, space group C2. The complex features a distorted square pyramidal [CuN 4 O] coordination with 5,5-dimethylhydantoinato, benzylamine and water ligands. The 5,5-dimethylhydantoinato anion is bonded to the copper(II) ion via its deprotonated N atom in the 3-position.

The complex-formation of the lanthanide(III) cations with D-penicillamine methyl ester have been investigated in acidic and neutral media. The macroscopic protonation constants of the ligand and the formation constants of [Ln·Pme] 2+ , [Ln·(Pme) 2 ]+, [Ln·Pme·OH] + and [Ln·Pme·(OH) 2 ] complexes have been determined from pH-metric data using BEST computer program. Species distribution diagrams of the complexes were obtained and plotted using SPE and SPEPLOT computer programs. Elemental analyses of the solid complexes indicate the formation of 1:1 metal:ligand species. Infrared spectra show that coordination takes place through the NH 2 , the SH and the C=O groups of the ligand. The complexes decompose in four steps as shown by their TG and DTA analysis with the formation of Ln 2 (SO 4 ) 3 as a final product. Activation energy values (ΔE a ) are correlated with the atomic radii of the metal ions. The mechanism of the thermal decomposition is proposed.

Preparation, X-ray crystal structure, thermal behavior, and IR spectroscopic studies of cis-diaquabis(1,10-phenanthroline)zinc(II) diorotate hydrate are described. In the compound [Zn(H 2 O) 2 (C 12 H 8 N 2 ) 2 ](C 5 H 3 N 2 O 4 ) 2 ·(H 2 O) 2.125 (1), the zinc ion, located on a twofold axis, is coordinated by two aqua ligands together with a pair of bidentate 1,10-phenanthroline (phen) molecules, and exhibits a distorted octahedral coordination. The orotate anions have a single negative charge each. The metal−coordinated water molecules link the orotate ions to the metal complex via O-H· · ·O hydrogen bonds. Also the uncoordinated water molecules are bonded to orotate ions through O-H· · ·O hydrogen bonds. Thus, an extensive network of hydrogen bonds together with π-π, and π-ring interactions stabilize the crystal structure and form an infinitive three dimensional structure. The thermal decomposition pathway of 1 has been investigated by the help of thermal analysis data (TG, DTG and DTA).

Bis(2-aminopyrimidine-N)diaquabis(saccharinato-O)copper(II) di(2-aminopyrimidine), [Cu(sac-O) 2 (ampym-N) 2 (H 2 O) 2 ] · 2ampym was synthesized and characterized by means of elemental analysis, IR and UV-vis spectroscopy, magnetic susceptibility, simultaneous TG, DTG, DTA techniques, and X-ray diffraction. The complex crystallizes in the monoclinic space group P21/c [a = 7.4697(5), b = 10.1679(5), c = 22.743(2)Å , β = 92.844(5), Z = 2, R = 0.0275, wR= 0.0757, V = 1725.26(19) Å 3 ]. The copper atom is bonded to two ampym N atoms and two sac O atoms as well as to two water O atoms in trans positions in the geometry of a distorted octahedron. There are also two ampym moieties as solvate molecules in the unit cell. The crystal structure is stabilized by N-H· · ·O, O-H· · ·N and C-H· · ·O type hydrogen bonding interactions. Intermolecular π−π interactions between the phenyl rings of ampym groups and C-H· · ·π interactions also support the packing of the molecules. The thermal decomposition of the complex has been studied.

The new thallide EuPdTl 2 , synthesized from the elements in a sealed tantalum tube in a highfrequency furnace, was investigated by X-ray diffraction on powders and single crystals: MgCuAl 2 type, Cmcm, Z = 4, a = 446.6(1), b = 1076.7(2), c = 812.0(2) pm, wR2 = 0.0632, 336 F 2 values, 16 variables. The structure can be considered as an orthorhombically distorted, palladium-filled variant of the binary Zintl phase EuTl 2 . The palladium and thallium atoms build up a three-dimensional [PdTl 2 ] polyanion with significant Pd-Tl (286 - 287 pm) and Tl-Tl (323 - 329 pm) interactions. The europium atoms fill distorted hexagonal channels of the [PdTl 2 ] polyanion. Susceptibility measurements show a magnetic moment of 7.46(5) μ B /Eu atom, indicative of divalent europium. EuPdTl 2 is a soft ferromagnet with a Curie temperature of T C = 12.5(5) K.

A new molybdenum oxynitride Y 2 Mo 2 O 4.5 N 2.5 with cubic pyrochlore structure (a = 10.3350(2) Å, space group Fd3̅m, Z =8) has been synthesized by heating the parent Y 2 Mo 2 O 7 oxide in flowing ammonia at 898 K. The polycrystalline sample has been characterized by thermal analysis, X-ray and neutron diffraction (NPD), and magnetic susceptibility measurements. The analysis of high resolution NPD data, based on the contrast existing between the scattering lengths of O and N, shows that both atoms are distributed at random at the anion substructure; the refined crystallographic formula implies an oxidation state of +5.25 for Mo cations. The thermogravimetric curve shows a weight gain of 7.5% at 1000 K in air, corresponding to the complete elimination of N 2 and oxidation to Mo(VI) oxide, in good agreement with the proposed composition. The magnetic susceptibility exhibits a Pauli-like, temperature-independent term which derives from the partial delocalization of Mo electrons on Mo-(O,N) bands with a broader bandwidth, as a consequence of the significant opening of the Mo-(O,N)-Mo angle and strengthening of the Mo-(O,N) interactions with respect to the parent Y 2 Mo 2 O 7 oxide. As in this oxide, a reminiscent spin-glass behaviour is observed at low temperature.

The organogallium compound [{Me 2 NCH 2 Ga(Cl,I) 2 } 2 ] (1) and the organoindium compounds [Me 2 NCH 2 In(Cl,Br) 2 ] 2 (2) and [Me 2 NCH 2 InCl 2 ] 2 (3) have been prepared by the reactions of the low valent metal halides “GaI”, InBr and InCl with the iminium salt [Me 2 N=CH 2 ]Cl. Compounds 1 and 2 are heterohalogen mixtures. These compounds were characterised by NMR spectroscopy and mass spectrometry, 1 furthermore by single crystal X-ray diffraction and 3 by elemental analysis. During the work-up procedure, minor amounts of hydrogen halide adducts of compounds 2 and 3 were isolated as single crystals, which contain a further equivalent of THF. These zwitter-ionic species Me 2 N(H)CH 2 In(Br,Cl) 3 ·THF (2·H(Cl,Br)·THF) and Me 2 N(H)CH 2 InCl 3 · THF (3 ·HCl ·THF) were identified by single crystal X-ray diffraction. Methylation reactions of compounds 1 and 2 with MeLi gave two well-established compounds [{Me 2 NCH 2 GaMe 2 } 2 ] and [{Me 2 NCH 2 InMe 2 } 2 ], which were obtained previously by different preparation procedures.

A new procedure for the synthesis of 2-(4-propylphenyl)ethanol is provided. This new procedure significantly reduces side-products as 1-(4-propylphenyl)ethanol and 2-bromoethanol, which are obtained when using the previously known procedure. Only with the new procedure an efficient purification on the large scale needed for avoided-level-crossing muon-spin resonance experiments was possible. Structural details of the title compound could be derived from an X-ray structure analysis of a crystalline derivative, the nitrobenzoyl ester.

It is shown theoretically that the ground state of a new class of non-Kekulé polymethine molecules can be a triplet state with non-degenerate singly occupied MOs. The investigated polymethine cyanine cations, polymethine oxonol anions, and neutral polymethine merocyanines are derivatives of the stable 2-azaphenalenyl radical whose pentamethine fragment is part of the polymethine chain.

Two new silver(I) saccharinate (sac) complexes, [Ag(sac)(pz)(H 2 O)] n (1) and [Ag(sac)(im)]·2H 2 O (2) (pz = pyrazole and im = imidazole), have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P2 1 /c and triclinic space group P1̅, respectively. The sac, pz and im ligands all are N-coordinated. In 1, the [Ag(sac)(pz)] units are bridged by aqua ligands to generate a one-dimensional helical chain, in which the silver(I) ions exhibit a distorted square-planar AgN 2 O 2 coordination geometry. The polymeric chains are connected by N-H· · ·O hydrogen bonds into sheets, which are further linked by aromatic π(pz) · · ·π(sac) stacking interactions into a three-dimensional supramolecular network. Complex 2 consists of individual molecules containing linearly coordinated silver(I) ions with a slightly distorted coordination of AgN 2 . The molecules interact with each other through hydrogen bonds and π· · ·π interactions to form a three-dimensional supramolecular network.

An efficient synthetic method has been developed for the preparation of symmetrical and unsymmetrical diaryl selenides through a one-pot reaction of diaryl diselenides and diaryliodonium salts in the presence of Zn/AlCl 3 system in aqueous media.

Catharanthus roseus cell suspension cultures were employed for the biotransformation of (-)-caryophyllene oxide (1), and four metabolites, 15-hydroxycaryophyllene oxide (2), 4β ,5α- dihydroxycaryophyll-8(13)-ene (3), 2β -hydroxycaryophyllene oxide (4), and 2-hydroxy-4,5- epoxycaryophyllan-13-ol (5) were obtained. Metabolites 4 and 5 were found to be new compounds, and their structures were deduced by different spectroscopic techniques.

Phytochemical studies on the methanolic extract of the leaves of Buxus hyrcana pojark, collected in Iran, have resulted in the isolation of two new triterpenoidal alkaloids, (+)-2α,16β ,31- triacetylbuxiran (1), (+)-2α,16β ,31-triacetyl-9-11-dihydrobuxiran (2). Spectroscopic methods were used to elucidate the structures of these new natural products.

The base catalyzed condensation reaction between 4-hydroxycoumarin and 3-acetylcoumarin (3-benzoylcoumarin) in water at reflux led to the formation of 1-methyl (1-phenyl)- benzopyrano[4’,3’-c]-benzo[3”,4”-ƒ ]-2,8-dioxabicyclo[3.3.1]nonane (2a, b) as final products. When 4-hydroxycoumarin and 3-acetylcoumarin reacted in a glacial acetic acid in the presence of potassium acetate the final product was 7-[3-acetyl-2-oxo-3,4-dihydro-2H-[1]benzopyran-4-yl]methyl- 6H,14H,14bH-bis-([1]benzopyrano)[4,3-b:4’,3’-d]pyran-6,14-dione (4). 4-Hydroxycoumarin and 4-(5-bromo-2-hydroxyphenyl)-3-buten-2-one were condensed in water at reflux and 1- methylcoumarino-[4’,3’-c]-bromobenzo[3”,4”-ƒ ]-2,8-dioxabicyclo[3.3.1]nonane was a final product (3).

1,3-Dipolar cycloaddition of azomethine ylides derived from acenaphthylene-1,2-dione and 5- methyl-benzo[b]-thiophene-2,3-dione with L-proline, thiazolidine-4-carboxylic acid and 1,2,3,4- tetrahydroisoquinoline-3-carboxylic acid with various electron deficient dipolarophiles leads to the formation of novel spiroheterocycles having two or more chiral centers. Semiempirical studies have been performed to understand the stereochemical course of the reaction. The synthesized cycloadducts have been screened for antimicrobial and toxicological activity.

A new cocrystal based upon 2,2’-diamino-4,4’-bis(1,3-thiazole) and 4,4’-bipyridine has been synthesized and characterized. Self-assembly of this compound in the solid state is likely caused by both hydrogen boding and π-π stacking, and the network contains large vacant voids.