Volume 66, Issue 2

The cubic iron hydroxy boracite Fe 3 B 7 O 13 OH・1.5H 2 O was synthesized from Fe 2 O 3 and B 2 O 3 under high-pressure/high-temperature conditions of 3 GPa and 960 °C in a modified Walker-type multianvil apparatus. The crystal structure was determined at room temperature by X-ray diffraction on single crystals. It crystallizes in the cubic space group F4̄3c (Z = 8) with the parameters a = 1222.4(2) pm, V = 1.826(4) nm 3 , R 1 = 0.0362, and wR 2 = 0.0726 (all data). The B-O network is similar to that of other cubic boracites. Graphical Abstract Synthesis and Characterization of a Cubic Iron Hydroxy Boracite

The new vanadoborate-supported zinc complex [Zn(teta)] 6 [(VO) 12 O 6 B 18 O 36 (OH) 6 ](H 2 O) ・8H 2 O (1, teta = triethylenetetramine) was synthesized hydrothermally and characterized by elemental and thermogravimetric analysis, and IR and UV/Vis spectroscopy. Complex 1 crystallizes in the trigonal system in space group R3̄ and consists of the neutral [Zn(teta)] 6 [(VO) 12 O 6 B 18 O 36 (OH) 6 ](H 2 O) cage aggregate that is built up from a [(VO) 12 O 6 B 18 O 36 (OH) 6 ] 12− cluster decorated with six [Zn(teta)] 2+ complex groups, and a water molecule occupying the center of the cluster cage. Graphical Abstract The New Vanadoborate-supported Hexanuclear Zinc Complex [Zn(teta)] 6 [(VO) 12 O 6 B 18 O 36 (OH) 6 ](H 2 O) · 8H 2 O

A hydrothermal reaction of Co(Ac) 2 ・ 4H 2 O, butane-1,2,3,4-tetracarboxylic acid (H 4 BTC), 1,10-phenanthroline (phen) and NaOH carried out at 160 °C yielded a new complex [Co 2 (H 2 O) 2 (phen) 2 (BTC)]. The complex has been characterized by single-crystal X-ray diffraction, IR spectroscopy, TG-DTA analyses, elemental analyses, powder X-ray diffraction, and magnetic measurements. The Co ions are linked by BTC 4− anions into a chain, and hydrogen bonding and π-π stacking interactions result in the formation of a 3D (3,4,6)-connected supramolecular architecture with the Schläfli symbol (43.62.8)2(46.66.83)(63)2. The temperature dependence of the magnetic susceptibility of the compound follows a Curie-Weiss law χm = C/(T −Θ) with C = 4.18(4) cm 3 mol −1 K and Θ = −1.43(5) K, and the magnetic behavior can be interpreted by means of a 1D chain Fisher model, where the magnetic superexchange is transmitted via π ···π stacking interactions between adjacent phen ligands, and the best fit results in J = −0.05 cm −1 , and zJʹ = 0.21 cm −1 . Graphical Abstract Synthesis, Topological Analysis and Properties of a Coordination Polymer with Butane-1,2,3,4-tetracarboxylato-bridged (Phenanthroline)cobalt(II) Units

Three new Cd(II) metal-organic coordination polymers, [Cd(bbi)(DNBA) 2 ] (1), [Cd(bbbi)- (DNBA) 2 ] (2), and [Cd(dmbbbi)(DNBA)Cl]·0.38H 2 O (3) [HDNBA = 3,5-dinitrobenzoic acid, bbi = 1,1-(1,4-butanediyl)bis(imidazole), bbbi = 1,1-(1,4-butanediyl)bis(benzimidazole), and dmbbbi = 1,1-(1,4-butanediyl)bis(5,6-dimethylbenzimidazole)], have been obtained from hydrothermal reactions of cadmium(II) chloride with the mixed ligands HDNBA and the three structurally related flexible bis(imidazole) derivatives. Single-crystal X-ray diffraction analyses have revealed that the dinuclear cadmium clusters acting as nodes interlinked by two μ 2- carboxylic groups, are connected to four other clusters through bridging bbi (for 1) and bbbi (for 2) units to generate two extended two-dimensional (2-D) networks. Compound 3 features a 1-D zigzag chain structure. A systematic structural comparison of the title compounds indicates that the conformations and the steric hindrance of flexible bis(imidazole) derivatives each play an important role in the formation of the Cd(II) coordination polymers. The thermal stability of 1 and 2, and the luminescence behavior of 3 were also investigated. Graphical Abstract Ligand-controlled Assembly of Cd(II) Metal-Organic Coordination Polymers Based on 3,5-Dinitrobenzoate and Flexible Bis(imidazole) Derivatives

Reactions of barium thiocyanate with trans-1,2-bis(4-pyridyl)ethylene (bpe) in acetonitrile/water using different molar ratios always lead to the formation of a new barium coordination polymer of composition {[[Ba(NCS)(H 2 O) 5 ]2](bpe)}(NCS) 2 (bpe) 3 (H 2 O) 2 (1). During the preparation of single crystals of compound 1, three additional new compounds were obtained (2 - 4), of which one crystallizes in two different polymorphic modifications (4I and 4II). In compound 1 the Ba cations are coordinated by six water molecules, two N-bonding thiocyanato anions and one N atom of a bpe ligand within an irregular polyhedron. Two Ba cations are linked by two water molecules and two μ- 1,1-N-bridging thiocyanato anions into centrosymmetric dimers that are further connected by the bpe ligands into chains. The coordination topology in the crystal structure of compound 2 is very similar to that in 1 in that two coordinating water molecules are exchanged by two terminal bpe ligands. As in 1, Ba dimers are observed that are connected by the bpe ligands into chains. In [[Ba(NCS) 2 ] 2 ]- (bpe) 3 (3) the barium cations are linked by two μ-1,3-bridging anions and one side-on-bridging thiocyanato anion into chains that are further linked by the bpe ligands into layers. In the first polymorphic modification of composition [Ba(NCS) 2 (bpe)(H 2 O)(CH 3 CN)]CH 3 CN (4I) each Ba cation is coordinated by one terminal N-bonding and two μ-1,1,3(N,Nʹ ,S)-bridging thiocyanato anions, two bridging water molecules, one acetonitrile molecule and one bpe ligand within an irregular polyhedron. The Ba cations are connected into chains that are further linked via O-H···N hydrogen bonding. The crystal structure of the second form 4II is very similar to that of form 4I, and significant differences are found predominantly in the packing of the complexes. Investigations using simultaneous differential thermoanalysis and thermogravimetry on compound 1 have shown that this compound decomposes in three steps with the formation of compound 3 in the second TG step. Graphical Abstract Synthesis, Crystal Structures and Properties of New Barium Thiocyanato Coordination Polymers with trans-1,2-Bis(4-pyridyl)ethylene as Ligand

Single crystals of Cs 2 (UO 2 )(NO 3 )Cl 3 were prepared by a hydrothermal method at 205 °C. The crystal structure has been solved by Direct Methods: monoclinic, P2 1 /n, a = 10.3748(13), b = 9.4683(13), c = 12.5535(16) Å, β = 110.280(2)◦, V = 1156.7(3) Å 3 , R 1 = 0.029. In the structure, strongly bonded linear uranyl cations UO 2 2+ are equatorially coordinated by two O and three Cl atoms to form (UO 2 )Cl 3 O 2 pentagonal bipyramids. Each bipyramid shares its O-O edge with an adjacent (NO 3 ) − anion to form finite clusters with the chemical composition [(UO 2 )(NO 3 )Cl 3 ] 2− . The Cs+ cations provide three-dimensional connectivity of the structure by forming Cs-O and Cs-Cl contacts to the uranyl nitrate chloride complexes. Related structures of mixed-ligand uranyl halides are compared. Graphical Abstract Crystal Chemistry of Uranyl Halides Containing Mixed (UO 2 )(X m O n ) 5 Bipyramids (X = Cl, Br): Synthesis and Crystal Structure of Cs 2 (UO 2 )(NO 3 )Cl 3

Zirconium oxide nitrides are active ammonia decomposition catalysts for the production of hydrogen. We present a route to zirconium oxide nitrides with high surface area. The precursor used consisted of a high-surface-area silica material coated with zirconium alkoxide. Subsequent hydrolysis and calcination resulted in ZrO 2 supported on SiO 2 . The high surface area of the material could be maintained in the following ammonolysis procedure leading to the corresponding zirconium oxide nitride. In contrast to the as-prepared ZrO 2 , the zirconium oxide nitrides exhibited a significant catalytic activity in ammonia decomposition, but compared to an iron oxide-based reference material, the new oxide nitrides showed a rather low activity. Nevertheless, zirconium oxide nitrides constitute suitable model systems for elucidating the effect of nitrogen in the anion substructure on the activity and selectivity of oxide-based ammonia decomposition catalysts. Graphical Abstract Präparation und Charakterisierung von SiO 2 -geträgerten Zirconiumoxidnitriden mit hoher Oberfläche und Untersuchung ihrer katalytischen Aktivität bei der Ammoniakzersetzung / Synthesis, Characterization, and Catalytic Activity of Zirconium Oxide Nitrides Supported on High-surface SiO 2

The reaction behavior of HF-HNO 3 -H 2 O etching mixtures, which are frequently used for texturing silicon surfaces, is significantly influenced by the addition of sulfuric acid. For high concentrations of sulfuric acid, nitronium ions NO 2 + ions have been detected by means of 14 N NMR spectroscopy, and results of Raman spectroscopic investigation have allowed the quantification of the nitronium ions. Maximum etching rates of 4000 - 5000 nm s −1 are reached for HF (40 %)-HNO 3 (65%)-H 2 SO 4 (97%) mixtures with w (40%-HF)/w (65%-HNO 3 ) ratios of 2 to 4 and w (97%-H 2 SO 4 )<0.3. For higher concentrations of sulfuric acid, H 2 SO 4 can be considered as a diluent. In order to investigate the influence of the sulfuric acid at constant HF and HNO 3 quantities, fuming HNO 3 (100 %) was used and the water in the mixtures successively replaced by H 2 SO 4 . A sudden increase of etching rates was found for sulfuric acid concentrations around 6 mol L −1 correlating with the characteristic color of the etching solutions. Decreased reaction rates at > 7 molL −1 H 2 SO 4 are attributed to high solution viscosities and the formation of fluorosulfuric acid. Generally, in HF-HNO 3 -H 2 SO 4 /H 2 O etching mixtures a reduced dissociation of nitric acid, the formation of nitronium ions, the solubility of neutral nitrogen intermediates (e. g. NO 2 , N 2 O 3 ), as well as other effects influence the attack of silicon surfaces. The structure of etched silicon surfaces was investigated by means of scanning electron (SEM) and laser scanning microscopy (LSM). The morphologies are influenced most significantly by the relative amounts of sulfuric acid. Unexpectedly, in nitronium ion-containing mixtures rough surfaces with pore-like etching pits are generated. Graphical Abstract HF-HNO 3 -H 2 SO 4 /H 2 O Mixtures for Etching Multicrystalline Silicon Surfaces: Formation of NO 2 + , Reaction Rates and Surface Morphologies

The alkylammonium alkylcarbamates 2, 4a,b, 14 were prepared from the amines 1, 3a,b, 13 and CO 2 . The crystal structures of 2 and 4b show carbamate anions, which are connected by N-H···O hydrogen bonds to form centrosymmetric dimers. The zwitterionic carbamates 7a,b, 8a,b and 11 are formed in the reactions of the diamines 6a,b and 10 with CO 2 . The crystal structures of 7a and 8b show strong intermolecular hydrogen bonds involving water molecules, the ammonium and the carbamate groups. In these compounds the molecules are interconnected in an extended two- or three-dimensional network. Due to the absence of crystal water molecules, the structure of 11 contains intermolecular hydrogen bonds involving the ammonium and the carbamate group in double-stranded chains. The diamines 17a,b react with CO 2 to give the zwitterionic carbamates 18a,b. Graphical Abstract Orthoamide und Iminiumsalze, LXX [1]. Zur Fixierung vonKohlendioxid mit organischen Basen (Teil 1) – Reaktionen von Diaminen mit Kohlendioxid / Orthoamides and Iminium Salts, LXX [1]. Capturing of Carbon Dioxide with Organic Bases (Part 1) – Reactions of Diamines with Carbon Dioxide

In our effort to obtain biologically active compounds, new 3,5-disubstituted 1,3-thiazolidine-2,4- diones (5a - r) were synthesized. A series of 5-arylmethylidene-1,3-thiazolidine-2,4-diones (3a - r) were prepared by Knoevenagel reaction from 1,3-thiazolidine-2,4-dione (2) and appropriate aromatic aldehydes. Condensation of 3a - r with 7-hydroxy-4-bromomethyl-2-oxo-2H-chromene (1) afforded novel 3-(7-hydroxy-2-oxo-2H-chromen-4-ylmethyl)-5-arylidene-1,3-thiazolidine-2,4-diones 5a - r. Compounds 3a - r and 5a - r were evaluated for their antioxidant activity (DPPH free radical scavenging activity). Graphical Abstract Design, Synthesis and Characterization of Some Novel 3-Coumarinyl- 5-aryliden-1,3-thiazolidine-2,4-diones and Their Antioxidant Activity

The 1 : 1 iminium intermediate, generated by the addition of a secondary amine to acetaldehyde is trapped by the (N-isocyanimino)triphenylphosphorane in the presence of an (E)-cinnamic acid derivative, leading to the formation of the corresponding iminophosphorane intermediate. Disubstituted 1,3,4-oxadiazole derivatives are formed via intramolecular aza-Wittig reaction of the iminophosphorane intermediates. The reactions were completed under neutral conditions at room temperature, and the corresponding disubstituted 1,3,4-oxadiazole derivatives were produced in excellent yields. Graphical Abstract Four-component Synthesis of 1,3,4-Oxadiazole Derivatives from (N-Isocyanimino)triphenylphosphorane, (E)-Cinnamic Acids, Acetaldehyde and Secondary Amines

The ionic liquid 1-butyl-3-methyl-imidazolium hydrogen sulfate, [bmim]HSO 4 , was used as a catalyst and reaction medium for the pyrrole synthesis, and a wide range of aliphatic, aromatic, heteroaromatic and carboxylic 1,4-diketones easily underwent condensations with aniline and ethylenediamine to form polysubstituted pyrroles. Sequential decarboxylation/Paal-Knorr pyrrole condensation was observed, which provides a new and facile approach to monoester pyrroles from 1,4-diketo-2,3-dicarboxylic acid esters. Graphical Abstract An Efficient Procedure for the Synthesis of Polysubstituted Pyrroles in an Ionic Liquid

The bisoxazoles 1a - 1c that feature structures with two oxazole moieties connected to a 2,6- pyridylene central linker and contain different aryl substituents in 4- and 5-positions of the oxazole rings have been synthesized. Single-crystal X-ray structure determinations of the free ligand 1a, containing the NiCl 2 complex of 1c as the CH 3 COOH solvate as well as the 1,4-dioxane-solvated diester intermediate 2a are reported, which show specific molecular conformations and packings in the crystals. The conformation of 1a is syn with reference to the oxazole nitrogen atoms and anti with reference to the oxazole and pyridine nitrogen atoms. In the Ni2+ complex, the metal ion is in an octahedral coordination environment with the nitrogens of 1c and an oxygen of an acetic acid molecule in the basal plane, while two chloride ions occupy the axial positions of three additional acetic acid molecules one is hydrogen-bonded to a chloride and two form a carboxylic dimer, thus giving rise to a 1 : 1 : 4 (1c: NiCl 2 :HOAc) stoichiometric ratio. The crystalline 1 : 1 inclusion compound of 2a with 1,4-dioxane suggests a typical clathrate owing to the bulkyness of the host molecule. Graphical Abstract New Pyridylene-bridged Bisoxazoles – Synthesis and Structural Study

The phosphide ScIrP was synthesized from the elements in a bismuth flux and characterized by powder and singlecrystal X-ray diffraction: ZrNiAl type, P6̄2m, Z = 3, a = 637.2(3), c = 389.2(2) pm, wR2 = 0.0280, 250 F 2 values, 15 variables. The two crystallographically independent phosphorus sites have tricapped trigonal-prismatic metal coordination P1Ir 3 Sc 6 and P2Ir 6 Sc 3 . The shortest interatomic distances occur for Ir-P (244 - 251 pm) within the 3D [IrP] network in which the scandium atoms fill cavities of coordination number 15 (4 Sc + 6 Ir + 5 P). Graphical Abstract ScIrP with ZrNiAl-type Structure

A metal-organic framework (MOF) was prepared from 1,4-di(pyridin-4-yl)buta-1,3-diyne and nickel(II) nitrate hexahydrate in methanol and dichloromethane at room temperature. The crystals are orthorhombic, space group C222 1 , Z = 4. The rhombic cavities of the MOF are occupied by disordered molecules of dichloromethane Graphical Abstract A Metal-Organic Framework Constructed of 1,4-Di(pyridin-4-yl)- buta-1,3-diyne and Nickel(II) Nitrate