bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrothermal Syntheses and Crystal Structures of Two New Mixed-valence Vanadium Oxides [Ni(en)2(H2O)2][Ni(en)3]2[V16O38Cl] · 3(H2O) and (H3O)2V3O8
Authors: Liu Xing , Yin Xian-Hong , Zhang Feng
Published: February 2015

Two vanadium oxides [Ni(en)2(H2O)2][Ni(en)3]2[V16O38Cl] ・3(H2O) (1) (en = ethylenediamine) and (H3O)2 V3O8 (2) were hydrothermally synthesized and characterized by single-crystal X-ray diffraction. 1 consists of [Ni(en)2(H2O)2]2+ and [Ni(en)3]2+ cations, discrete [V16O38Cl]6− cluster anions and H2O molecules, while 2 consists of anionic mixed-valent V5+/V4+ vanadium oxide layers constructed from pairs of corner-sharing VVO4 tetrahedra and VIVO5 square pyramids, with H3O+ cations occupying the interlayer space. Both 1 and 2 were synthesized under the same reaction conditions but with different V/Ni molar ratios, which shows that the reactant stoichiometry of the system plays a key role in the formation of different structures in the products.
A Vanadyl(V) Complex with a Pincer-type Thiobis(phenolate) and an Acetylacetonate Co-ligand, VO(tbp)(acac)
Authors: Bikas Rahman , Monfared Hassan Hosseini , Alami Somayeh , Pantenburg Ingo , Meyer Gerd
Published: February 2015

A new vanadyl(V) complex with the tridentate, pincer-type O,S,O-ligand thiobis(phenolate), tbp, was synthesized from the reaction of vanadium(IV) oxide bis(acetylacetonate), VO(acac)2, and 2,2’- thio-bis(4-methylphenol), H2tbp, in refluxing methanol in high yield. Single-crystal X-ray diffraction structure analysis revealed for VO(tbp)(acac) that the vanadium atom is octahedrally coordinated with an O5,S-donor environment where the thiobis(phenolate) ligand is O,S,O-bonded to the vanadyl(V) center facially in a tridentate dinegative fashion. Cyclic voltammetric experiments carried out with its solution in dimethyl sulfoxide revealed an irreversible peak at −0.768 V (vs. Ag/AgCl) relating to the V5+/V4+ reduction process.
Synthesis and Crystal Structures of Copper(II), Zinc(II), Lead(II) and Cadmium(II) Tetrazole-5-carboxylate Complexes Generated via in situ Hydrolysis Reaction
Authors: Kou Jun-Feng , Su Meng , Zhang Yu-Hong , Huang Zhan-Dong , Ng Seik Weng , Yang Guang
Published: February 2015

Four metal complexes, namely [Cu2(ttzCOO)2(H2O)4]・4H2O (1), [Zn2(ttzCOO)2(H2O)6]・2H2O (2), [Pb(ttzCOO)(H2O)2]n (3), and {[Cd(ttzCOO)(H2O)]・1/2H2O}n (4), where ttzCOO2− = tetrazole-5-carboxylate dianion, have been prepared by the reaction of the sodium salt of 1Htetrazole- 5-carboxylic acid ethyl ester in aqueous methanolic solution at room temperature with CuCl2, ZnI2, Pb(NO3)2, or Cd(NO3)2, respectively. The compounds were characterized by elemental analysis, IR spectroscopy, TG-DSC analysis and single-crystal X-ray diffraction. While 1 and 2 are structurally similar dinuclear complexes, 3 and 4 exhibit a 1D chain structure and a 3D polymeric framework, respectively.
5-Aminouracil as a Building Block in Heterocyclic Synthesis: Part III. One-pot Synthesis of Novel Pyrimido[5,4-b]quinoline-2,4,9-triones and Pyrimido[5,4-c]isoquinolines
Authors: Shaker Raafat M. , Sadek Kamal U. , Hafez Ebtisam A. , Elrady Mohamed Abd
Published: February 2015

An efficient and direct procedure for the synthesis of pyrimido[5,4-b]quinoline-2,4,9-trione and pyrimido[5,4-c]isoquinoline derivatives has been described. The products were characterized by elemental analyses, IR, 1H NMR, 13C NMR and MS spectra.
Synthesis and Crystal Structure of Nb0.84N
Authors: Frenzel Nancy , Irran Elisabeth , Lerch Martin , Buchsteiner Alexandra
Published: February 2015

A new compound of the composition Nb0.84N was prepared by ammonolysis of NbO2 at 1100 °C. The crystal structure refinement was performed by the Rietveld method using X-ray and neutron powder diffraction data. Nb0.84N crystallizes in the trigonal space group R3m (no. 166) with the lattice parameters a = 298.5(2) and c = 2384.3(4) pm. The niobium atoms form a close packing with a layer sequence which can be described by the Jagodzinski symbol hhc. The nitrogen atoms fill all octahedral voids. Along [001] a sequence of two layers of trigonal NbN6 prisms and one layer of NbN6 octahedra is formed. The nitrogen positions are fully occupied, the niobium positions only partially. Nb0.84N is part of a family of crystal structures between the anti-NiAs and the NaCl type consisting of close-packed metal layers with varying stacking sequences
The Metal-rich Phosphide Ce4Ir13.55P9
Authors: Pfannenschmidt Ulrike , Rodewald Ute Ch. , Pöttgen Rainer
Published: February 2015

Needle-shaped crystals of the metal-rich phosphide Ce4Ir13.55P9 were synthesized from the elements in a lead flux (starting composition 1 : 2 : 2 : 60) at 1370 K followed by slow cooling. Ce4Ir13.55P9 crystallizes with a new orthorhombic structure type: Pnma, a = 1269.1(2), b = 399.1(1), c = 3349.9(7) pm, wR2 = 0.0722, 2025 F2 values and 139 variables. Two of the 14 crystallographic iridium sites show small defects. All phosphorus atoms have slightly distorted tricapped trigonal prismatic metal coordination by cerium and iridium. The iridium and phosphorus atoms build up a threedimensional [Ir13.55P9]δ− polyanion in which the cerium atoms fill distorted hexagonal cavities. Within the polyanion the phosphide anions are isolated, and one additionally observes a broad range of Ir-Ir bonding (Ir-Ir distances 278 - 298 pm). From a geometrical point of view the Ce4Ir13.55P9 structure can be considered as an intergrowth structure of distorted ThCr2Si2- and SrPtSb-related slabs
AlkalineEarthMetal-Hydride-Iodide Compounds: Syntheses andCrystal Structures of Sr2H3I and Ba5H2I3.9(2)O2
Authors: Reckeweg Olaf , DiSalvo Francis J.
Published: February 2015

Single crystals of Sr2H3I andBa5H2I3.9(2)O2 were obtained by reacting Sr or Ba, respectively, with dried and sublimed NH4I in a 4 : 1 molar ratio in silica-jacketed Nb ampoules for 13 h at 1200 K. The crystal structures of the new compounds have been determined by means of single-crystal X-ray diffraction. Sr2H3I crystallizes in a stuffed anti-CdI2 structure isotypic to Ba2H3Cl in the space group P3m1 (no. 164) with the lattice parameters a = 426.0(1) and c = 774.9(2) pm, while Ba5H2I3.9(2)O2 crystallizes in a new structure type in the space group Cmcm (no. 63) with the lattice parameters a = 1721.0(2), b = 1452.5(2) and c = 639.03(9) pm. The structural results for Sr2H3I are corroborated by EUTAX calculations. For the disordered compound Ba5H2I3.9(2)O2, EUTAX calculations on an approximated, ordered structural model were used to find possible insights into the disorder
Synthesis and Structural Characterization of the Dinuclear Beryllium Species [Be2Cl2(μ-Cl)2(PCy3)2]
Authors: Braunschweig Holger , Gruß Katrin
Published: February 2015

The synthesis and full characterization of [Be2Cl2(μ-Cl)2(PCy3)2], which results from the reaction of [Pd(PCy3)2] and BeCl2 with concomitant precipitation of elemental palladium, is reported
An Alternative and Efficient Route to Chlorophacinone
Authors: Csuk René , Barthel Alexander , Ströhl Dieter
Published: February 2015

A straightforward synthesis for the anticoagulant rodenticide chlorophacinone is described. The short synthesis uses commercially available mandelic acid and 1,3-indanedione as staring materials
The New Vanadoborate-supported Hexanuclear Zinc Complex [Zn(teta)]6[(VO)12O6B18O36(OH)6](H2O) · 8H2O
Authors: Liu Xing , Zhou Jian
Published: February 2015

The new vanadoborate-supported zinc complex [Zn(teta)]6[(VO)12O6B18O36(OH)6](H2O) ・8H2O (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)12O6B18O36(OH)6](H2O) cage aggregate that is built up from a [(VO)12O6B18O36(OH)6]12− cluster decorated with six [Zn(teta)]2+ complex groups, and a water molecule occupying the center of the cluster cage.
Synthesis, Topological Analysis and Properties of a Coordination Polymer with Butane-1,2,3,4-tetracarboxylato-bridged (Phenanthroline)cobalt(II) Units
Authors: Zhu Hong-Lin , Zheng Yue-Qing
Published: February 2015

A hydrothermal reaction of Co(Ac)2 ・ 4H2O, butane-1,2,3,4-tetracarboxylic acid (H4BTC), 1,10-phenanthroline (phen) and NaOH carried out at 160 °C yielded a new complex [Co2(H2O)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 BTC4− 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) cm3 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.
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
Authors: Tiritiris Ioannis , Kantlehner Willi
Published: February 2015

The alkylammonium alkylcarbamates 2, 4a,b, 14 were prepared from the amines 1, 3a,b, 13 and CO2. 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 CO2. 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 CO2 to give the zwitterionic carbamates 18a,b.
Design, Synthesis and Characterization of Some Novel 3-Coumarinyl- 5-aryliden-1,3-thiazolidine-2,4-diones and Their Antioxidant Activity
Authors: Čačić Milan , Molnar Maja
Published: February 2015

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).
Four-component Synthesis of 1,3,4-Oxadiazole Derivatives from (N-Isocyanimino)triphenylphosphorane, (E)-Cinnamic Acids, Acetaldehyde and Secondary Amines
Authors: Ramazani Ali , Ahmadi Yavar , Nasrabadi Fatemeh Zeinali
Published: February 2015

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.
{[(PhCH2Sn)12(μ3-O)14(μ-OH)6](F3CSO3)2}: A New Dodecanuclear Organostannoxane
Authors: Plasseraud Laurent , Cattey Hélène , Richard Philippe
Published: February 2015

The new dodecanuclear organostannoxane {[(PhCH2Sn)12(μ3-O)14(μ-OH)6](F3CSO3)2} (2) has been isolated as single crystals from the reaction of trifluoromethanesulfonic acid (F3CSO3H) with the decanuclear dibenzyltin(IV)-oxo cluster, [(PhCH2)2SnO]6{[(PhCH2)2SnOH]2(CO3)}2 (1), in [D3]acetonitrile, at room temperature. Compound 2 was structurally characterized by X-ray diffraction analysis, multinuclear NMR and IR spectroscopy, mass spectrometry, and thermogravimetry. The structure of 2 can be described as a football cage framework containing twelve tin atoms, exhibiting two distinct coordination geometries, penta- and hexacoordinated respectively, and linked together through μ3-O and μ-OH ligands. Resulting from Sn-C bond cleavage, all tin atoms are only connected to one benzyl ligand. Furthermore, two of the three oxygen atoms of each trifluoromethanesulfonate counteranions are involved in hydrogen bonding interactions with bridging μ-OH groups of two distinct Sn12 cations leading to the propagation of a two-dimensional polymeric network.
First Principles Investigation of the Stability and the Chemical Behavior of Hydrogen in ThCoH4
Authors: Matar Samir F.
Published: February 2015

We address the changes in the electronic structure brought by the insertion of hydrogen into ThCo leading to the experimentally observed ThCoH4. Full geometry optimization positions the hydrogen in three sites stabilized in the expanded intermetallic matrix. From a Bader charge analysis, hydrogen is found to be in a narrow iono-covalent (~−0.6) to covalent (~−0.3) bonding which should enable site-selective desorption. The overall chemical picture shows a positively charged Thδ+ with the negative charge redistributed over a complex anion {CoH4}δ− with δ~1.8. Nevertheless this charge transfer remains far from the one in the more ionic hydridocobaltate anion CoH5
4− in Mg2CoH5, due to the largely electropositive character of Mg.
A New 1D Coordination Polymer Constructed From a Dissymmetrical Oxamidate Ligand: Structure and Magnetic Properties
Authors: Liu Bao Lin , Dang Juan , Tao Ruo Jie
Published: February 2015

A new complex {{[Cu(oxbe)]Cu(tmen)}2・2ClO4}n (H3oxbe = N-benzoato-Nʹ-(2-aminoethyl)- oxamido, tmen = N,N,Nʹ,Nʹ-tetramethylethylenediamine) has been synthesized and characterized by IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction, and by its magnetic properties. It crystallizes in the triclinic system, space group P¯1, with a = 1.364(2), b = 1.379(2), c = 1.516(3) nm, α = 64.402(3), β = 66.098(3), γ = 89.604(3)°, V = 2.301(7) nm3, Z = 2, Dcalcd. = 1.71 g cm−3. The structure of 1 consists of tetranuclear units. Through syn-anti carboxylate bridges, the complex features a chain structure.
A Procedure for Rapid Determination of the Silicon Content in Plant Materials
Authors: Neumann Mike , Nöske Robert , Bach Grete , Glaubauf Thomas , Bartoszek Michael , Strauch Peter
Published: February 2015

An efficient, reliable and low-cost procedure to determine the silicon content in plant material is presented which allows to monitor the agricultural aspects like growth and yield. The presented procedure consists of a hydrochloric acid pre-treatment and a subsequent thermal oxidation. The method is compared to other processes like dissolution in hydrofluoric acid combined with ICP OES, energy-dispersive X-ray fluorescence spectroscopy (EDXRF) or aqua regia treatment.
Syntheses, Structures and Photoluminescent Properties of the Two Novel Coordination Polymers [Cd(pydc)2(tu)]n and [Cd2(SO4)(nic)2(tu)1.5(H2O)2]n (pydc = Pyridine-2,3-dicarboxylate, nic = Nicotinate, tu = Thiourea)
Authors: Xu Chao , Liu Sheng-Bo , Duan Taike , Chen Qun , Zhang Qian-Feng
Published: February 2015

Two novel cadmium coordination polymers, [Cd(pydc)2(tu)]n (1) and [Cd2(SO4)(nic)2(tu)1.5 - (H2O)2]n (2) (pydc = pyridine-2,3-dicarboxylate, nic = nicotinate, tu = thiourea), have been synthesized under hydrothermal conditions and structurally characterized by X-ray diffraction analysis. 1 is a one-dimensional ladder coordination polymer in a two-dimensional network formed by hydrogen bonds. 2 consists of two kinds of Cd(II) centers in different coordination environments connected via nicotinate and sulfate to form a two-dimensional grid network integrated in a three-dimensional framework generated by hydrogen bonds. 2 shows intense fluorescent emission in the solid state at room temperature
An Efficient Synthesis of 1-Thia-5-azaspiro[5.5]undec-2-ene and its Recyclization to 1,5-Diazaspiro[5.5]undec-2-ene and/or Spiro-Thieno[2,3-d]pyrimidin-4(1H)-one Derivatives
Authors: Shaker Raafat M. , Hamoda Asmaa , Ibrahim Yusria R. , El-Shaieb Kamal M. , Abdel-Latif Fathy F.
Published: February 2015

An efficient and direct synthesis of 1-thia-5-azaspiro[5.5]undec-2-ene is described, and the basecatalyzed recyclization of this compound was studied. The products have been characterized by elemental analyses, and IR, MS, 1H NMR, and 13C NMR spectroscopy
Assembly of 1,2,3,4-Benzenetetracarboxylic Acid and Zinc(II) Metal Centers to a Chiral 3D Metal-organic Framework: Syntheses, Structure and Properties
Authors: Ji Can , Zang Shuang-Quan , Liu Jun-Yi , Li Jia-Bin , Hou Hong-Wei
Published: February 2015

A new three-dimensional metal-organic framework {[Zn(mpda)0.5(bix)]·(H2O)1.5}n (1) (H4mpda = 1,2,3,4-benzenetetracarboxylic acid, m-bix = 1,3-bis(imidazol-1-ylmethyl)-benzene) has been synthesized and characterized by single-crystal X-ray diffraction and IR spectra. In 1, homochiral helical chains are formed in the Zn-mpda layer through spontaneous resolution by mpda4−. Such layers are further connected through the second m-bix ligand to form a 3D chiral metal-organic framework. The individual (4,4)-connected net in 1 can be specified by the Schläfli symbol (66)2(64.82). Bulk material of 1 has good second-harmonic generation (SHG) activity, approximately 0.4 times that of urea. In addition, a thermogravimetric analysis was carried out, and the photoluminescent behavior of the complex was also investigated
Synthesis, Crystal Structure and Luminescence Properties of the Inorganic-Organic Hybrid Compound [FTMA]2[CdI4] (FTMA = Ferrocenylmethyltrimethylammonium Cation)
Authors: Bai Yan , Zhang Guo Qiang , Dang Dong Bin , Qi Ze Yan , Zhang Li
Published: February 2015

The title compound [FTMA]2[CdI4] has been synthesized from [FTMA]I (ferrocenylmethyltrimethylammonium iodide) and 3CdSO4・8H2O and was characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The Cd(II) atom has a slightly distorted tetrahedral coordination sphere. In the solid state there are C-H・ ・ ・π interactions between adjacent ferrocenyl cations to generate a chain structure. The luminescence properties of the title compound were investigated in the solid state at room temperature
Chains of Condensed RuSm6/2 Octahedra in Sm3RuMg7 – A Ternary Ordered Version of the Ti6Sn5 Type
Authors: Linsinger Stefan , Pöttgen Rainer
Published: February 2015

The magnesium-rich intermetallic compound Sm3RuMg7 was synthesized by induction melting of the elements. Single crystals were grown by slow cooling of the polycrystalline sample. The structure was characterized by powder and single-crystal X-ray diffraction: ordered Ti6Sn5 type, P63/mmc, Z = 2, a = 1034.1(2), c = 611.3(1) pm, wR2 = 0.0216, 399 F2 values and 19 parameters. The ruthenium atoms have slightly distorted octahedral samarium coordination. These RuSm6/2 octahedra (Ru-Sm 279 pm) are condensed via common faces leading to chains in the c direction which are arranged in the form of a hexagonal rod packing. Between these rods the Mg2 atoms build chains of face-sharing trigonal prisms. Alternately these prisms are centered by Mg3 or capped by Mg1 atoms on the rectangular faces. Within the magnesium substructure the Mg-Mg distances range from 303 to 335 pm. The Mg3 site shows slight mixing with samarium, leading to the composition Sm3.16RuMg6.84 for the investigated crystal. The compounds RE3RuMg7 (RE = Gd, Tb) are isotypic.
Synthesis, Crystal Structure and Properties of a New Lanthanide Pyridine-2,4,6-tricarboxylato Coordination Polymer
Authors: Lin Jian-Li , Xu Wei , Zhao Li , Zheng Yue-Qing
Published: February 2015

A new lanthanide pyridine-2,4,6-tricarboxylato coordination polymer, [Dy2(H2O)5(ptc)2]·H2O (H3ptc = pyridine-2,4,6-tricarboxylic acid), was hydrothermally synthesized. The complex exhibits both mono-capped square antiprismatic DyNO8 chromophores and 4,4ʹ-bicapped trigonal prismatic DyNO7 chromophores, which are interconnected through ptc3− anions in μ3η6 and μ4η6 coordination modes to achieve a new 3D MOF of an unprecedented topology of (4 · 63 · 82)(63) type. This Dy(III) complex exhibits a characteristic luminescence in the visible region upon excitation at 300 nm. The temperature-dependent magnetic properties of the Dy(III) complex were investigated in the temperature range of 2 - 300 K.
Novel Phenylazo Derivatives of Condensed and Uncondensed Thiophene. Synthesis, Characterization, and Antimicrobial Studies
Authors: Gaber Hatem M. , Bagley Mark C. , Sherif Sherif M. , Sayed Mohsen A.
Published: February 2015

In the search for new therapeutic agents against microbial infections, two novel series of monocyclic and tricyclic 5-(phenylazo)thiophene systems were synthesized based on 3-amino-2-thioxopyrimidinone and 2-cyanoacetamidothiophene derivatives 4 and 6. Functionalization of the pyrimidine ring in precursor 4 resulted in the formation of the target tricyclic condensed thiophenes 7, 12, and 13a, b, by the application of a variety of addition, substitution, and condensation reactions. On the other hand, derivatization of the versatile cyanoacetylated compound 6 led to a second series of monocyclic N-substituted aminothiophenes 15, 17, 19, and 20, through convenient methods. The new thiophene-based derivatives were tested for their antimicrobial activity with reference to relevant standard drugs. They displayed different levels of antibacterial activity, with compound 7 showing essentially the highest antipseudomonal activity. As for antifungal action, the compounds under investigation, unfortunately, had no inhibitory effects against test fungi isolates except for 7 and 20, that revealed slight inhibition.
Photocatalytic Ring Opening of α-Epoxyketones in Cyclopentanone
Authors: Memarian Hamaid R. , Shokuhimehr Gholrokh , Soleymani Mousa
Published: February 2015

Electron transfer-induced ring opening of α-epoxyketones by 2,4,6-triphenylpyrylium tetrafluoroborate (TPT) in cyclopentanone resulted in the diastereoselective formation of 2,5-dioxaspiro[4,4]- nonanes through Cα-O bond cleavage and following nucleophilic attack of cyclopentanone to radical cation intermediates. The readiness for ring opening is influenced by the nature and the location of the additional s`ubstituent on the α-epoxyketones.
Hydrothermal Synthesis and Crystal Structure of a Nickel(II) Coordination Polymer with 1,1ʹ-Biphenyl-2,2ʹ-dicarboxylato- 6,6ʹ-dicarboxylic Acid and 2,2ʹ:6,2ʺ-Terpyridine Ligands
Authors: Mei Chong-Zhen , Shan Wen-Wen , Liu Bing-Tao
Published: February 2015

A new metal-organic framework {[Ni(H2BPTC)(tpy)- (H2O)] · (H2O)3}n (1) (H4BPTC = 1,1ʹ-biphenyl-2,2ʹ,6,6ʹ- tetracarboxylic acid, tby = 2,2ʹ:6,2ʺ-terpyridine) has been synthesized and characterized by single-crystal X-ray diffraction and IR spectroscopy. The one-dimensional metalorganic chains of the title complex, namely {Ni(H2BPTC)- (tpy)(H2O)}n, are connected through weak π · · ·π and C- H· · ·π interactions to form layers, which are further held together by rich O-H· · ·O hydrogen bonding to give a threedimensional supramolecular network. The thermal stability of the title complex was studied by thermal gravimetric (TG) and differential thermal analyses (DTA).
Ternary Stannides RE3Ru4Sn13 (RE = La, Ce, Pr, Nd) – Structure, Magnetic Properties, and 119Sn Mössbauer Spectroscopy
Authors: Mishra  , Schwickert Christian , Langer Thorsten , Pöttgen Rainer
Published: February 2015

The ternary stannides RE3Ru4Sn13 (RE = La, Ce, Pr, Nd) were obtained by arc-melting of the elements. The polycrystalline samples were characterized by powder X-ray diffraction. The structures of three compounds were refined from single-crystal diffractometer data: Yb3Rh4Sn13 type, Pm3̄n, a = 977.74(3) pm, wR2 = 0.0379, 280 F2 values for La3Ru4Sn13, a = 971.34(9) pm, wR2 = 0.0333, 274 F2 values for Ce3Ru4Sn13, a = 970.68(8) pm, wR2 = 0.0262, 272 F2 values for Nd3Ru4Sn13 with 13 variables per refinement. The structures consist of three-dimensional networks of condensed RuSn6/2 trigonal prisms with the RE (CN 16) and Sn2 (CN 12) atoms in two different types of cavities of the networks. The two crystallographically independent tin sites have been resolved by 119Sn Mössbauer spectroscopy. Temperature-dependent magnetic susceptibility measurements of Ce3Ru4Sn13 gave a reduced magnetic moment of 2.32 μB per Ce atom, indicating intermediate cerium valence. No magnetic ordering was evident down to 3 K.
Intermetallic REPtZn Compounds with TiNiSi-type Structure
Authors: Mishra Trinath , Pöttgen Rainer
Published: February 2015

The equiatomic rare earth compounds REPtZn (RE = Y, Pr, Nd, Gd-Tm) were synthesized from the elements in sealed tantalum tubes by high-frequency melting at 1500 K followed by annealing at 1120 K and quenching. The samples were characterized by powder X-ray diffraction. The structures of four crystals were refined from single-crystal diffractometer data: TiNiSi type, Pnma, a = 707.1(1), b = 430.0(1), c = 812.4(1) pm, wR2 = 0.066, 602 F2, 21 variables for PrPt1.056Zn0.944; a = 695.2(1), b = 419.9(1), c = 804.8(1) pm, wR2 = 0.041, 522 F2, 21 variables for GdPt0.941Zn1.059; a = 688.2(1), b = 408.1(1), c = 812.5(1) pm, wR2 = 0.041, 497 F2, 22 variables for HoPt1.055Zn0.945; a = 686.9(1), b = 407.8(1), c = 810.4(1) pm, wR2 = 0.061, 779 F2, 20 variables for ErPtZn. The single-crystal data indicate small homogeneity ranges REPt1±xZn1±x. The platinum and zinc atoms build up three-dimensional [PtZn] networks (265 - 269 pm Pt-Zn in ErPtZn) in which the erbium atoms fill cages with coordination number 16 (6 Pt + 6 Zn + 4 Er). Bonding of the erbium atoms to the [PtZn] network proceeds via shorter RE-Pt distances, i. e. 288 - 293 pm in ErPtZn.
Synthesis, Crystal Structure and Properties of a Cobalt(II) Coordination Polymer with Cyclohexane-1,2,3,4,5,6-hexacarboxylic Acid
Authors: Xu Wei , Zheng Yue-Qing
Published: February 2015

Hydrothermal reaction of CoCl2 ・ 6H2O, H6chhc (all-cis-1,2,3,4,5,6-cyclohexanehexacarboxylic acid), phen (1,10-phenanthroline), and NaOH in aqueous solution afforded a new coordination polymer Co(phen)(H2O)(H2chhc), which crystallizes in the space group P1̄ with the cell constants a = 7.267(2), b = 10.749(2), c = 10.826(2) A° , α = 97.86(3), β = 103.62(3), γ = 95.00(3)◦, V = 807.8(3) °A3 and Z = 2. The [Co(phen)(H2O)]2+ cations in the title complex are interlinked by the di-protonated (H2chhc)4− anions in a η6μ4 bridging mode to form 1
∞[Co(phen)(H2O)(H2chhc)1/2] polymer chains running along the [100] direction. Variable temperature magnetic susceptibility studies revealed the presence of weak, long-range antiferromagnetic ordering and zero-field splitting [J = −0.32(5) cm−1 and D = 11.5(1) cm−1 with g = 2.306(4)]. The IR spectrum and results of thermal and elemental analyses are also presented.
Sesquiterpene Lactones from Cichorium intybus
Authors: Shah Shazia , Ali Zulfiqar , Malik Abdul , Khan Ikhlas A. , Saied Sumayya
Published: February 2015

Two new sesquiterpene lactones (guaianolides), 15-hydroxytaraxacin (1) and 6,8,11-epi-desacetylmatricarin (2), along with three known compounds, desacetylmatricarin (3), 11β ,13-dihydrolactucin (4), and 11β ,13-dihydrolactucopicrin (5), were isolated from the aerial parts of Cichorium intybus L.
Gingerol Derivatives from the Rhizomes of Zingiber Officinale
Authors: Wang Zhi , Wang Kai-Jin , Cheng Chen-Shu , Li Ning , Wang Tian-Ming , Dia Lei
Published: February 2015

Two new gingerol derivatives, [8]-gingesulfonic acid (1) and [10]-gingesulfonic acid (2), were isolated from the rhizomes of Zingiber officinale, along with nine known gingerol derivatives, [6]- gingesulfonic acid (3), 1-dehydro-[6]-gingerdione (4), 1-dehydro-[8]-gingerdione (5), 1-dehydro- [10]-gingerdione (6), [6]-gingerdione (7), [10]-gingerdione (8), [6]-gingerol (9), methyl [6]-gingerdiol (10), and 6-hydroxyl-[6]-shogaol (11). Their structures were elucidated on the basis of spectral evidence and comparisons with literature data.
Structure Refinement and Magnetic Properties of Ce2RuAl3 and a Group-Subgroup Scheme for Ce5Ru3Al2
Authors: Mishra Trinath , Hoffmann Rolf-Dieter , Schwickert Christian , Pöttgen Rainer
Published: February 2015

The hexagonal Laves phase Ce2RuAl3 (≡ CeRu0.5Al1.5) was synthesized by high-frequencemelting of the elements in a sealed tantalum tube and subsequent annealing. The structure was refined from single-crystal X-ray diffraction data: MgZn2 type, P63/mmc, Z = 2, a = 565.38(9), c = 888.3(1) pm, wR2 = 0.0231, 193 F2 values and 13 parameters. The 2a (0.824 Ru + 0.176 Al) and 6h (0.956 Al + 0.044 Ru) Wyckoff positions show mixed occupancies leading to the composition CeRu0.48Al1.52 for the investigated crystal. The aluminum atoms build up Kagomé networks at z = 1/4 and z = 3/4 which are connected to a three-dimensional network by the ruthenium atoms. The cerium atoms fill cavities of coordination number 16 (3 Ru + 9 Al + 4 Ce) within the [RuAl3] network. The Ce2RuAl3 sample orders ferromagnetically at TC = 8.0(1) K. The cerium-rich aluminide Ce5Ru3Al2 shows unusually short Ce-Ru distances of 253 and 260 pm for the Ce1 position as a result of intermediate cerium valence. The structural distortions are discussed on the basis of a group-subgroup scheme for Pr5Ru3Al2 (space group I213) and the superstructure variant Ce5Ru3Al2 (space group R3).
Ternary Antimonides RE2Ir3Sb4 (RE = La, Ce, Pr, Nd)
Authors: Schäfer Konrad , Hermes Wilfried , Rodewald Ute Ch. , Hoffmann Rolf-Dieter , Pöttgen Rainer
Published: February 2015

The antimonides RE2Ir3Sb4 (RE = La, Ce, Pr, Nd) were synthesized by arc-melting of the elements and subsequent annealing or via high-frequency melting. The samples were characterized by X-ray powder diffraction, and the four structures were refined from single-crystal X-ray diffraction data: Pr2Ir3Sb4 type, Pnma, Z = 4, a = 1621.9(2), b = 458.60(8), c = 1099.8(1) pm, wR2 = 0.036, 1558 F2 values for La2Ir3Sb4, a = 1616.6(8), b = 456.5(2), c = 1094.8(5) pm, wR2 = 0.092, 1080 F2 values for Ce2Ir3Sb4, a = 1613.0(5), b = 454.9(2), c = 1094.1(5) pm, wR2 = 0.057, 1428 F2 values for Pr2Ir3Sb4, and a = 1609.8(6), b = 452.9(2), c = 1092.3(5) pm, wR2 = 0.052, 1472 F2 values for Nd2Ir3Sb4, with 56 parameters per refinement. The Sb1 atoms show enhanced displacement off the mirror planes at y = 1/4 and y = 3/4. A series of temperature-dependent structure refinements of Pr2Ir3Sb4 down to 90 K are indicative of static disorder. The iridium and antimony atoms build up covalently bonded three-dimensional [Ir3Sb4] networks with Ir-Sb distances ranging from 256 -269 pm (Nd2Ir3Sb4). The two crystallographically independent rare earth sites fill cavities of coordination numbers 17 (8 Ir + 9 Sb) and 15 (6 Ir + 9 Sb) within the [Ir3Sb4] polyanions. Temperature-dependent magnetic susceptibility measurements indicate a stable trivalent ground state for the cerium compound. No magnetic ordering was evident down to 3 K.
A Rare Example of a Dinuclear Cobalt(II) Complex with Dipicolinate and Bridging 2-Aminopyrazine Ligands. Preparation, Structural, Spectroscopic and Thermal Characterization
Authors: Tabatabaee Masoumeh , Kukovec Boris-Marko , Razavimahmoudabadi Vajieh
Published: February 2015

A dinuclear cobalt(II) complex, [Co2(H2O)4(dipic)2(μ-apyz)] (dipicH2 = pyridine-2,6-dicarboxylic (dipicolinic) acid, apyz = 2-aminopyrazine) (1), has been hydrothermally synthesized and characterized by elemental analyses, spectroscopic methods (IR, UV/Vis), thermal analysis as well as by X-ray diffraction studies. The dinuclear complex is composed of two cobalt(II) ions bridged by a 2-aminopyrazine molecule. Each cobalt(II) ion is coordinated by one nitrogen and two oxygen atoms of the tridentate dipicolinate anion, one heterocyclic nitrogen atom of the 2-aminopyrazine and two oxygen atoms of coordinated water molecules. The resulting geometry for the CoN2O4 coordination environment can be described as distorted octahedral. Various hydrogen bonds of the type O-H···O and N-H···O are also present in the crystal structure. This arrangement leads to the formation of a 3D structure.
Synthesis, Crystal Structures, and Spectroscopic and Thermal Properties of New Cobalt Thiocyanato Coordination Compounds Based on 3-Methylpyridine as a Neutral Coligand
Authors: Boeckmann Jan , Reimer Björn , Näther Christian
Published: February 2015

Reaction of cobalt(II) thiocyanate with 3-methylpyridine in water leads to the formation of the new ligand-rich cobalt(II) thiocyanato coordination compounds [bis(thiocyanato-N)-tetrakis(3-methylpyridine- N)cobalt(II)] (1) and [bis(thiocyanato-N)-bis(3-methylpyridine-N)-diaqua-cobalt(II)] (2). The crystal structures of 1 and 2 consist of discrete complexes in which the cobalt(II) cations are coordinated by two terminally N-bonded thiocyanato anions and four or two terminally bonded coligands, respectively, in a slightly distorted octahedral geometry. Investigations on the thermal degradation behavior of 1 and 2 using simultaneous differential thermoanalysis and thermogravimetry as well as X-ray powder diffraction and IR spectroscopy have proven that on heating a stepwise decomposition takes place, which leads to the formation of the new phase-pure ligand-deficient intermediate [bis(thiocyanato-N)-bis(3-methylpyridine-N)cobalt(II)] (3). The crystal structure of 3 also consists of discrete complexes, but the cobalt(II) cations are only tetrahedrally coordinated by two terminally N-bonded thiocyanato anions and two terminally bonded coligands. The structures and the thermal properties are discussed and compared with that of related transition metal thiocyanato coordination compounds.
Caesium Tetrachlorido Aurate(III), CsAuCl4
Authors: Kraus Florian
Published: February 2015

The crystal structure of caesium tetrachlorido aurate(III), CsAuCl4, is presented. The compound crystallizes in the form of orange, needle-shaped single crystals in the monoclinic space group C2/c with a = 12.923(2), b = 6.1715(9), c = 96512(13) Å , β = 105.049(13)°, V = 743.34(19) Å3, and Z = 4. As expected, the compound consists of isolated Cs+ cations and square planar AuCl4
- anions
Preparation, Photophysical, Electrochemical, and Ion-Binding Properties of Ru(II) Polypyridyl Complexes Containing a Crown Ether Unit
Authors: Cheng Feixiang , Tang Ning , Chen Jishu , Wang Fan , Chen Longhai
Published: February 2015

Two polypyridyl ligands, 4`-(4,5-diazafluoren-9-ylimino)benzo-15-crown-5 (L1) and 4` -(4,5-diazafluoren- 9-ylimino)benzo-12-crown-4 (L2), and their Ru(II) complexes [(bpy)2RuL1](PF6)2 and [(bpy)2RuL2](PF6)2, respectively, have been synthesized and characterized. The two complexes display metal-to-ligand charge transfer absorptions at around 444 nm in CH3CN solution at r. t. and emission at around 573 nm in an EtOH-MeOH (4 : 1, v/v) glassy matrix at 77 K. Electrochemical studies of the complexes show one Ru(II)-centered oxidation at around 1.33 V and three ligandcentered reductions. The binding ability of the complexes with Na+ and Li+ has been investigated by UV/Vis absorption and emission spectroscopy and electrochemical titrations. Addition of Na+ and Li+ to solutions of the complexes results in a progressive quenching of the emission, a hyperchromic effect of the UV/Vis absorption, and a progressive cathodal shift of the Ru(II)-centered E1/2 potential. The stability constants for the stoichiometric 1 : 1 ratio of the complexes and the cations have been obtained by UV/Vis absorption titration.
An Efficient Synthesis of Rubin’s Aldehyde and its Precursor 1,3,5-Tribromo-2,4,6-tris(dichloromethyl)benzene
Authors: Holst Christoph , Schollmeyer Dieter , Meier Herbert
Published: February 2015

2,4,6-Tribromobenzene-1,3,5-tricarboxaldehyde (4) can be efficiently prepared in two reaction steps from 1,3,5-tribromobenzene. The intermediate 1,3,5-tribromo-2,4,6-tris(dichloromethyl)benzene (3) crystallizes from petroleum ether in its C3h structure. However, in CDCl3 solution it exists at room temperature in two isomeric forms: 3a (C3h) and 3b (Cs) (1:1.15).The intramolecular Br・・・Cldistances are much smaller than the sum of the van der Waals radii. Therefore, the exocyclic C-C bonds show a hindered rotation.
Crystal and Molecular Structure of Palladium(II) and Silver(I) Complexes with Oxotetrazolinate Ligands [1-Me-N4C(O)]-
Authors: Noth Heinrich , Burger Klaus , Beck Wolfgang
Published: February 2015

The structures of (n-Bu3P)2Pd[1-Me-N4C(O)]2 (1) and of (Ph3P)3Ag[1-Me-N4C(O)] ・ 1-Me-4-H-N4C(O) (2) were determined by X-ray crystallography. The oxotetrazolinate ligands are N4-coordinated in contrast to the corresponding Scoordinated tetrazole-thionates.
Synthesis and Crystal Structure Determination of a Guanidine Adduct of Sodium Guanidinate, NaCN3H4(CN3H5)2
Authors: Hoepfner Veronika , Englert Ulli , Dronskowski Richard
Published: February 2015

Well-grown single crystals of NaCN3H4(CN3H5)2 were synthesized from guanidine and sodium hydride. The new compound crystallizes in the monoclinic space group P21/n (no. 14) with Z = 4 and a = 6.2007(4), b = 9.6261(8), c = 15.7630(11) A° and β = 93.783(3)◦ at 293 K. The asymmetric unit comprises two sodium cations on special positions, one guanidinate anion and two symmetry-independent guanidine molecules. The structure is built up from columns of facesharing NaN6 octahedra oriented along the crystallographic a axis. The coordinating organic ligand anions and molecules are connected by hydrogen bonds from amino H atoms to imino N atoms to generate a tube-like motif. These tubes are then linked by two more hydrogen bonds to form a threedimensional network.
A Dodecanuclear Copper(I) Complex Containing a Cubic (CuS)4 Core Stabilized by a Tripodal (N,N,P)-Chelating Ligand
Authors: Meinholz Margret M. , Stalke Dietmar
Published: February 2015

We present the structure elucidation of a copper(I) complex of a monoanionic phosphanylalkyl-diimido sulfonate ligand centered by a sulfur-copper cube. It has the formula [{Me2PCH2S(NSiMe3)2}4 Cu8{CuS}4] (2) and is the first example of a copper(I) complex of this new ligand type.
The Influence of d10-d10 Interactions in Ag5Te1.8Se0.2Cl and Ag5Te1.6Se0.4Cl on Structural and Thermoelectric Properties
Authors: Eckstein Nadine , Bobet Jean-Louis , Chevalier Bernard , Nilges Tom
Published: February 2015

Measurements of the thermopower and of the thermal diffusivity and a detailed analysis of the structural features by temperature-dependent single-crystal structure determinations of silver ionconducting Ag5Te1.8Se0.2Cl and Ag5Te1.6Se0.4Cl were performed to investigate the interaction of silver ions in their disordered state. The substituted phases show an order/disorder phase transition at 273.3(2) and 302.5(2) K, respectively, accompanied by a drop of the thermal diffusivity and a minimum plateau of the thermopower right after the transition. Silver ions are arranged in welldefined strands along the crystallographic c axis characterized by a set of not fully occupied sites. Ag5Te1.6Se0.4Cl shows a negative thermal expansion during temperature rise right after the silver order/disorder phase transition; this is explicable by attractive d10-d10 interactions within the disordered silver substructure. After the minimum values of the thermopower have been reached, these values rise in parallel to the decrease of the d10-d10 interactions. Ag5Te1.6Se0.4Cl shows a very low value of the thermal diffusivity of 0.070 mm2 s−1 at 300.7 K.
Neue Lanthan-Stannide/Germanide: La3Sn4.4Ge0.6, La3Sn3.1Ge0.9 und La9Sn6.7Ge3.3 / New Lanthanum Stannide/Germanides: La3Sn4.4Ge0.6, La3Sn3.1Ge0.9 and La9Sn6.7Ge3.3
Authors: Dürr Ines , Röhr Caroline
Published: February 2015

Three new ternary mixed lanthanum stannide/germanides have been synthesized and characterized in the course of a systematic study of the phase formation at the 3 : 5, 3 : 4 and 1 : 1 pseudo-binary sections of the ternary system La - Ge - Sn, i. e. a study of the ’coloring’ in mixed tetrelides. The structures of the title compounds have been determined using single-crystal X-ray data, and the electronic structure was analyzed by means of simple electron counting rules and FP-LAPW band structure methods. Even a very minor substitution of Sn by Ge in the 3 : 5 stannide La3Sn5 already changes the structure from the Pu3Pd5 type of the binary stannide towards the Tl4PbTe3 type (La3Sn4.4Ge0.6: tetragonal, space group I4/mcm, a = 861.35(10), c = 1211.48(13) pm, Z = 4, R1 = 0.0420). According to the anionic building blocks present, isolated [Ge/Sn]4− anions and heavily puckered 4.82 nets of three-bonded tin atoms (i. e. [Sn4]4− Zintl ions), a small formal electron excess (+9/−8) occurs, which is also apparent from the position of the minimum in the calculated tDOS. In contrast, starting from the known binary stannide La3Sn4 (orthorhombic, space group Cmcm, Er3Ge4 structure type) a substitution of tin by germanium is possible without a change of the structure type up to the border composition La3Sn3.1Ge0.9 (a = 448.61(5), b = 1170.68(14), c = 1556.0(2) pm, Z = 4, R1 = 0.0380). Germanium preferentially occupies the sites of the [Ge/Sn]3 trimers, whereas the site of the square-planar coordinated Sn(3), which is stabilized by hypervalent bonding, is not populated by germanium. Taking the respective partial bonding into account, the Zintl electron count is also nearly exact (+9/−8). The new complex mixed tetrelide La9Sn6.7Ge3.3 (tetragonal, space group P42/ncm, a = 1602.04(3), c = 1724.42(5) pm, Z = 8, R1 = 0.0706) exhibits nine crystallographically different tetrel positions, which are occupied by isolated Sn and Ge atoms, [Sn/Ge]2 dumbbells, bent [Sn3] trimers, planar four-membered rings [Ge4], and planar six-membered rings [M6]. In this compound, the electron count following the Zintl concept also reveals only a very small formal excess of electrons (+54/−52).
Crystal Structure and Magnetic Properties of the Novel Hollandite Ba1.3Co1.3Ti6.7O16
Authors: Shlyk Larysa , Niewa Rainer
Published: February 2015

Single crystals of the new barium hollandite Ba1.3Co1.3Ti6.7O16 were obtained from a BaCl2 flux (I2/m, Z = 1, a = 9.9470(4), b = 2.9714(2), c = 10.2260(5) Å , β = 90.906(2)◦). In the crystal structure piles of Ba atoms are situated within a framework of edge- and vertex-sharing octahedra (Co,Ti)O6. The composition was deduced from microprobe analyses, structure refinements and charge balance arguments in agreement with the observed magnetic properties. The temperature dependence of the magnetic susceptibility χ(T) of Ba1.3Co1.3Ti6.7O16 single crystals reveals paramagnetism down to 2 K. The value of the Co magnetic moment deduced from the Curie-Weiss law agrees well with the theoretical value of the high-spin state spin-only moment of μeff = 3.87 μB for Co2+ (S = 3/2)
Basic Beryllium ortho-Fluorobenzoate and its Mono-hydroxo Derivative
Authors: Berger Raphael J. F. , Jana Surajit , Fröhlich Roland , Mitzel Norbert W.
Published: February 2015

The preparation of tetraberyllium-μ4-oxo-hexa[η2-(ortho-fluorobenzoate)] [Be4O(o-C6H4FCOO) 6, 2] and tetraberyllium-μ4-oxo-μ2-hydroxo-penta[η2-(ortho-fluorobenzoate)] [Be4(o-C6H4F-COO)5(OH), 3] from silver ortho-fluorobenzoate and BeCl2 in Et2O/thf solution containing varying amounts of water is reported. The single-crystal structures of 2·tetrahydrofuran and 3·Et2O·2 hexane are discussed in comparison with the structure of the known basic beryllium and zinc carboxylates [M4O(RCOO)6, M = Be, Zn]. DFT calculations show that lower symmetry has to be expected for Be-based M4O-framework-type compounds as compared to the corresponding Zn compounds. Compound 2 is a potential precursor for new compounds with MOF substructure motifs
Synthese, Struktur und optoelektronische Eigenschaften von para- und meta-Bismethylborylbenzol-Komplexen mit 5-Fluor-2-(2´-pyridyl)indol
Authors: Heilmann-Brohl Julia , Schdel Frauke , Bolte Michael , Wagner Matthias , Lerner Hans-Wolfram
Published: February 2015

To examine their luminescence behavior, two air-stable BN addition compounds were synthesized by the reaction of 5-fluoro-2-(2′-pyridyl)indole with 1,4- and 1,3-bis(bromo(methyl)boryl)benzene, respectively. Both BN adducts are luminescent. Their emission maxima (1,3-substituted BN adduct: 495 nm; 1,4-substituted BN adduct: 497 nm) are comparable with the value (490 nm) of the related mono-borylated benzene species, which is composed of a BPh2 fragment and a 5-fluoro-2-(2′-pyridyl) indole unit. The starting materials 1,4- and 1,3-bis(bromo(methyl)boryl)benzene were accessible by treatment of 1,4- or 1,3-bis(dibromoboryl)benzene with two equivalents of SnMe4. In addition, the results of the X-ray structure analyses of the B,B′-bis-5-fluoro-2-(2′-pyridyl)indolyl-complexed meta-bismethylborylbenzene fragment (9, triclinic, P1̅) as well as of 5-chloro-2-(2′-pyridyl)indole (2, monoclinic, P21/c) and 5-fluoro-2-(2′-pyridyl)indole (1, orthorhombic, Pca21) are reported. The pyridylindole derivatives of this approach were synthesized by an optimized two-step procedure from 2-acetylpyridine and 4-fluoro- or 4-chlorophenylhydrazine hydrochloride
Investigations into the Regioselectivity of Fischer Indole and Friedländer Quinoline Syntheses with Octahydroisobenzofuran and Octahydroisoindole Derivatives
Authors: Bender Matthias , Christoffers Jens
Published: February 2015

A Fischer indole synthesis with a cis-configurated octahydroisobenzofuran-6-one yielded exclusively a furo[3,4-c]carbazole derivative as the product of a regioselective angular annulation reaction. A Friedländer quinoline synthesis from the same substrate gave a mixture of angular and linear annulation products, i. e. furo[3,4-a]acridine and furo[3,4-b]acridine derivatives. When submitting a mixture of cis- and trans-octahydroisoindole derivatives to Fischer and Friedländer syntheses, the trans-starting material gave regioselectively linear annulation products, i. e. pyrrolo[3,4-b]carbazole and pyrrolo[3,4-b]acridine derivatives. In contrast, the respective cis-configurated isoindole gavemixtures of angular and linear annulation products. The constitutions and relative configurations of nine new indole and quinoline derivatives were established by 2D NMR experiments and X-ray singlecrystal investigations.
Pyridine-promoted Cyclization of Functionalized N-Silylated Boron-Nitrogen Compounds
Authors: Schurz Fanny , Jansen Martin
Published: February 2015

Dichloroboryldisilylamines [SiClm(CH3)3−m]N[Si(CH3)3](BCl2) (m = 1 - 3) as well as chloromethylboryl- bis-(chlorodimethylsilyl)amine [SiCl(CH3)2]2N[BCl(CH3)] form 1 : 1 adducts with pyridine (1 - 4). Those with m = 2 and 3 have been converted into functionalized diazadiboretidine derivatives which are still coordinated by pyridine: [(SiClm(CH3)3−m)NBCl · Py]2 (5: m = 2, 6: m = 3). Single-crystal X-ray diffraction structure analyses confirm the presence of planar, rhombusshaped, four-membered boron-nitrogen rings with tetra-coordinated boron atoms and nitrogenbonded, chlorine-functionalized silyl groups, for both compounds.
Synthesis, Characterization and Luminescence of Silver(I) and Gold(I) Complexes Bearing a Diethyl Acetal Functionalized N-Heterocyclic Carbene
Authors: Leitner Sebastian , List Manuela , Monkowius Uwe
Published: February 2015

1-(2,2ʹ-Diethoxyethyl)-3-methyl-imidazolium bromide, 1, has been prepared and used as a precursor for the synthesis of the corresponding silver bromide complex [(NHC)2Ag][AgBr2], 2. Transmetallation of 2 with (tht)AuBr (tht = tetrahydrothiophene) yields (NHC)AuBr, 3. The solid-state structures of 2 and 3 have been determined by single-crystal X-ray diffraction revealing a loose aggregation of the complexes by weak metal-metal interactions. Due to the presence of these contacts, both complexes are emissive in the solid state.