bluuebunny/crossref_metadata_2025 huggingface dataset:
Darstellung, Schwingungsspektren und Normalkoordinatenanalyse von (n-Bu4N)2[Pt(SCN)n(ox)], n = 2, 4, sowie Kristallstruktur von [(C5H5N)2CH2][Pt(SCN)4(ox)] / Synthesis, Vibrational Spectra and Normal Coordinate Analysis of (n-Bu4N)2[Pt(SCN)n(ox)], n = 2, 4, and Crystal Structure of [(C5H5N)2CH2][Pt(SCN)4(ox)]
Authors: Uttecht J.-G. , Nöther C. , Preetz W.
Published: August 2018

On exposure of trans-(n-Bu4N)2[Pt(SCN)2(ox)2] to photochemical reduction (n-Bu4N)2- [Pt(SCN)2(ox)] (1) is formed. Further treatment with (SCN)2 yields (n-Bu4N)2- [Pt(SCN)4(ox)] (2). The X-ray structure determination on a single crystal was performed of [(C5H5N)2CH2][Pt(SCN)4 (ox)] (triclinic, space group P1̅, a = 9.823(1), b = 14.850(1), c = 15.799(1) Å , α= 74.304(9), β= 86.268(9), γ= 87.455(9)°, Z = 4). Based on the molecular parameters of the X-ray determination the IR and Raman spectra have been assigned by normal coordinate analysis. The valence force constants of the symmetric axis S-Pt-S and of the asymmetrically coordinated S'-Pt-O* axes are fd(PtS) = 1.71, fd(PtS') = 1.92 (1), fd(PtS') = 2.02 (2) and fd(PtO•) = 2.45 (1) and 2.24 (2) mdyn/Å. Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved. The NMR shifts are δ(195Pt) = 1967.7 (1) and 2930.8 ppm (2)
Nitridsulfidhalogenide der leichten Lanthanide vom Typ M6N3S4X (M = La - Nd; X = Cl, Br) mit ausgeordneten Sulfid- und Halogenid-Lagen / Nitride Sulfide Halides of the Light Lanthanides with the Formula Type M6N3S4X (M = La - Nd; X = Cl, Br) with Ordered Sulfide and Halide Positions
Authors: Lissner Falk , Schleid Thomas
Published: August 2018

The oxidation of the light lanthanides (M = La - Nd) with sulfur and NaN3 in the presence of the tribromides MBr3 yields bromine-poor nitride sulfide bromides with the composition M6N3S4Br when appropriate molar ratios of the reactants are used. Additional NaBr as a flux secures complete and fast reactions (7 d) at 850 °C in evacuated silica tubes as well as singlecrystals of the pure phase (brownish needles). The orthorhombic crystal structure (Pnma, Z = 4) was determined from single crystal X-ray data for La6N3S4Br (a = 1159.23(9), b = 410.85(3), c = 2765.6(2) pm), Ce6N3S4Br (a = 1152.31(9), b = 407.52(3), c = 2747.4(2) pm), Pr6N3S4Br (a = 1145.42(9), b = 404.21(3), c = 2729.3(2) pm), and Nd6N3S4Br (a = 1138.59(9), b = 400.94(3), c = 2711.3(2) pm). Six crystallographically different M3+ cations are present, two of them (M1 and M2) build up chain I (1
∝ {[NM2]3+}) by cis-edge connection of [NM4] tetrahedra. The four remainders (M3 - M6) arrange as pairs [N2M6] of edge-shared [NM4] units which are further connected via four vertices to form a double chain (chain II = 1
∝ {[N2M4]6+}). Bundled along [010] like a closest packing of rods, both types of chains are commensurate in translation and held together by one Br- and four S2- anions which, in contrast to an earlier work on the pseudo-isotypic chloride analogues M6N3S4Cl (M = La - Nd), are perfectly ordered.
DFT Calculations of the Structures of Various Isomers (cis/trans) of [(CH3)(PH3)M-NH2-CH2-C(O)-O] and [(Cl)(PH3)M-NH2-CH2-C(O)-O] Complexes with M = Ni, Pd and Pt
Authors: Beck Wolfgang , Klapötke Thomas M. , Ponikwar Walter
Published: August 2018

The structural parameters of the following neutral complexes [(CH3)(PH3)M-NH2-CH2-C(O)-O] and [(Cl)(PH3)M-NH2-CH2-C(O)-O], M = Ni, Pd, Pt (P and N in cis and trans position) were computed at the density functional BPW91 level of theory using a 6-31++G(2d,p) basis set for H, C, N, O, P, Cl and Ni, and quasi-relativistic core potentials for Pd (ECP28MWB) and Pt (ECP60MWB) employing a (8s7p6d)/[6s5p3d] valence basis set. The structures were fully optimised without any symmetry constraints and were found to represent true minima (number of imaginary frequencies, NIMAG= 0). In the series ofmethyl complexes for the Ni and the Pd complexes, the trans isomers were found to be slightly more stable than the cis isomers by 1.9 (Ni) and 0.6 (Pd) kcal mol-1. In the case of the Pt complex, both isomers were computed to be essentially identical in their total energy with the cis isomer being only 0.25 kcal mol-1 more stable than the trans isomer. However, in the chloro series, the trans isomers were found to be more favourable than the cis isomers in all cases by 9.7 (Ni), 7.5 (Pd) and 6.5 (Pt) kcal mol-1. This finding is in perfect accord with the experimental data for a series of palladium and platinum complexes of the type Cl(R3P)M(N,O-chelate) for which the trans-P-M-N structure has been determined by X-ray diffraction. These complexes crystallize obviously as the thermodynamically stable trans isomers.
Studies of Monothiomalonamide and its Palladium(II) and Platinum(II) Complexes
Authors: De Beukeleer Sabrina , Papaefstathiou Giannis S. , Raptopoulou Catherine P. , Terzis Aris , Perlepes Spyros P. , Desseyn Herman O. , Manessi-Zoupa Evy
Published: August 2018

A project related to the crystal engineering of hydrogen bonded coordination complexes has been initiated and our first results are presented here. The cis and trans forms of monothiomalonamide (LH2) have been fully characterized by vibrational spectroscopy, thermal techniques and single-crystal X-ray diffraction. The cis form crystallizes in the monoclinic space group P21/c and the trans form in the monoclinic space group C2/c. The respective lattice constants are a = 5.602(3), b = 9.055(2), c = 10.945(5)Å , β = 101.29(2)" (cis-LH2) and a = 20.336(7), b = 4.317(1), c = 12.432(5) Å, β = 92.16(1)" (trans-LH2). The new complexes [Pd(LH2)4]X2 (X = Cl, Br), [Pt(LH2)4]X2 (X = Br, I), [PdX2(LH2)2] (X = Cl, Br, I) and [PtX2(LH2)2] (X = Cl, I) were prepared and characterized by elemental analyses and spectroscopic (IR, far-IR, Raman) studies. All data are discussed in terms of the nature of bonding in conjunction with assigned structures. The LH2 molecule behaves as a monodentate ligand binding through the sulfur atom. Monomeric square planar structures are assigned for the metal complexes in the solid state; the 1:2 complexes have the trans geometry. A detailed comparison of the new complexes with the corresponding monothiooxamide complexes is also presented.
Polysulfonylamine, CLXI. Ein neuartiges 1,2-Dihydroimidazochinolinylium-Kation: Zufällige Isolierung und Kristallstruktur des entsprechenden Dimesylamids Polysulfonylamines, CLXI. A Novel 1,2-Dihydroimidazoquinolinylium Cation: Serendipitous Isolation and Crystal Structure of the Corresponding Dimesylamide
Authors: Wijaya Karna , Moers Oliver , Blaschette Armand , Jones Peter G.
Published: August 2018

Orange-coloured 1,2-dihydro-2,2-dimethyl-imidazo[4,5,1-ij]quinolinylium dimesylamide (1) was accidentally obtained on treating 8-aminoquinoline with one equivalent of dimesylamine in acetone solution. To the best of the authors’ knowledge, the tricyclic cation in question or congeners thereof have not been reported previously. The crystal structure of 1 (monoclinic, space group P21/c, Z = 4; - 130 °C) consists of (MeSO2)N- layers, between which the cations are intercalated to form centrosymmetric (π-π)-bonded pairs. Each cation is connected to the adjacent anion layers by a conventional NDH···(O,N) three-centre hydrogen bond and a set of weak C(sp2)DH···O = S and CH2DH···O = S interactions.
Crystal and Molecular Structure of 4-Arylhexahydro-1H,3H-pyrido[1,2-c]pyrimidine-1,3-dione Derivatives
Authors: Wolska Irena , Herold Franciszek
Published: August 2018

The X-ray crystal structure determination of 4-(2-methylphenyl)hexahydro-1H,3H-pyrido[ 1,2-c]pyrimidine-1,3-dione (2) and 4-(3-methylphenyl)hexahydro-1H,3H-pyrido[1,2-c]- pyrimidine-1,3-dione (3) is reported. The crystal structures show the formation of centrosymmetric dimers via intermolecular N-H···O hydrogen bonds. The saturated ring adopts a slightly distorted halfchair conformation in both 2 and 3. In either compound the planar phenyl ring is twisted with respect to the pyrimidine-1,3-dione fragment.
Ni(C2(COO)2)(H2O)4 · 2 H2O und Ni(C2(COO)2)(H2O)2: zwei Koordinationspolymere mit dem Acetylendicarboxylat-Dianion / Ni(C2(COO)2)(H2O)4 · 2 H2O and Ni(C2 (COO)2)(H2O)2: Two Co-ordination Polymers of the Acetylenedicarboxylate Dianion
Authors: Hohn Frauke , Billetter Heinrich , Pantenburg Ingo , Ruschewitz Uwe
Published: August 2018

From a solution of Ni(CH3COO)2 ∙ 4 H2O and acetylenedicarboxylic acid in deionized water single crystals of Ni(C2(COO)2)(H2O)4 ∙ 2 H2O(P21/a, Z = 2, isotypic to Co(C2(COO)2)(H2O)4 ∙ 2 H2O) were obtained by slow evaporation of the solvent. In the solid state structure nickel is octahedrally surrounded by four water molecules and two oxygen atoms of the carboxylate anions. These octahedra are connected to chains by the dicarboxylates. Heating the hexahydrate to 100 °C in a stream of argon leads to Ni(C2(COO)2)(H2O)2 (C2/c, Z = 4, isotypic to Mn[C2(COO)2] ∙ 2 H2O). Here, the NiO6 octahedron is built by two water molecules and four oxygen atoms of the dicarboxylate ligands, which connect the Ni octahedra to a three-dimensional network. Thermoanalytical investigations show another mass loss at about 200 °C, which leads to non-crystalline products. Finally, at about 400 °C NiO is formed. Measurements of the magnetic susceptibilities result in the expected behaviour for Ni2+ in an octahedral co-ordination (3A2 ground state). The effective magnetic moment at room temperature is μeff = 3.20 μB.
Peri-Interactions in Naphthalenes, 9 [1]. On Hypercoordination in Non-Quaternary Phosphonium Salts and a Secondary Phosphine with the (8-Dimethylamino-Naphth-1-Yl) Substituent
Authors: Schiemenz Günter Paulus , Näther Christian , Pörksen Simon
Published: August 2018

The 31P NMR data of non-quaternary (8-dimethylamino-naphth-1-yl)phosphonium salts, with emphasis on the 1J(31P, 1H) coupling constants, where scrutinized for their potential to yield information about N→P dative interactions. As for δ (29Si) and 1J(29Si, 1H) in the isosteric silanes, the data do not permit conclusions in favour of such interactions. 1J(31P, 1H) of bis(8-dimethylaminonaphth- 1-yl)phosphine in conjunction with the distances d(N···P) invalidates the basic assumption on which the claim of dative N→P/Si bonding in such phosphorus and silicon compounds rests, viz. that N···P/Si distances of ca. 270 pm are evidence for P/Si-hypercoordination. No evidence for hydrogen bonds N···H-P was found.
Beryllium Dichloride Coordination by Nitrogen Donor Molecules
Authors: Dressel Martina P. , Nogai Stefan , Berger Raphael J. F. , Schmidbaur Hubert
Published: August 2018

The reaction of anhydrous beryllium chloride with nitrogen donors L in diethylether as a solvent under mild conditions affords 1:2 complexes of the type L2BeCl2 [L = benzonitrile (1), pyridine (2), 3,5-dimethylpyridine, pyrrolidine, piperidine (8), and diethylamine (10)]. Structural studies of compounds 1, 2, 8 (CHCl3), and 10 have shown that the complexes have the beryllium centers N2Cl2- tetracoordinated with a distorted tetrahedral geometry of the core unit. In crystals of 8 and 10 these molecules are associated to form helical strings via distinct N-H-Cl hydrogen bonding. The reaction of the weak donor pyrazole (pyz) with (Et2O)2BeCl2 at low temperature gives the mixed complex [(Et2O)(pyz)BeCl2] (4), in which one diethylether molecule is retained in the inner coordination sphere of the metal. In tetrahydrofuran (thf) solution, no reaction is observed with pyrazole, indicating that tetrahydrofuran is the stronger donor as compared to pyrazole, and the (thf)2BeCl2 solvate remains intact. By contrast, with the strong base pyrrolidine (pyrr) the same reaction leads to substitution of one chloride ligand to give the ionic product [(pyrr)3BeCl]+Cl−, (7). Both products (4, 7) have been structurally characterized. At room temperature the reactions with pyrazole or piperidine lead to ether cleavage as a side-reaction which may even become dominant at long reaction times and more forcing conditions. Dinuclear complexes of the type [LBeCl(μ2-OR)]2 are formed, the structures of which have also been determined. The results suggest that hydrogen bonding may assist in the ether cleavage process, since this reaction is not observed for ligands devoid of N-H functions.
Ba9[NbN4]2O[Cn2] – Synthesis, Crystal Structure and Raman Spectrum
Authors: Reckeweg Olaf , DiSalvo Francis J.
Published: August 2018

Red transparent single crystals of Ba9[NbN4]2O[CN2] were synthesised by the reaction of BaO coated Ba metal, C and Nb powder in arc-welded Nb ampoules at 1300 K. The title compound was characterised by X-ray single crystal diffraction (P1̅ , a = 799.05(2), b = 962.61(2) and c = 1264.38(4) pm; α = 75.859(1), β = 85.745(1) and γ = 87.8621(8)°; Z = 2) and Raman spectroscopy (νsym = 1234 and δ = 632/658/668 cm−1). It now seems likely that a nitride-azide compound we previously reported, Ba9[NbN4]2N[N3], does not exist, but is in fact the title compound.
Decarbonylation of Pentamethylcyclopentadienyl Tetracarbonylvanadium, Cp*V(CO)4, in the Presence of Oxygen. The X-Ray Crystal Structure Analyses of Cp*V(CO)4 and [Cp*V(O)(μ-O)]4
Authors: Herberhold Max , Dietel Anna-Maria , Milius Wolfgang
Published: August 2018

The reaction of Cp*V(CO)4 (1) with molecular oxygen in diluted pentane solution leads to a tetrameric dioxide, [Cp*V(O)(μ-O)]4 (2), which is a precursor of the octanuclear aggregate Cp*6V8O17 (3). The molecular structures of 1 and 2 have been determined by X-ray crystallography.
Formation of a Doubly C,N-Bridged Six-Membered Metallacyclic Bis[(2-imidazolyl)zirconocene] Dication
Authors: Vagedes Dominik , Erker Gerhard , Kehr Gerald , Fröhlich Roland , Grimme Stefan , Mück-Lichtenfeld Christian
Published: August 2018

Treatment of 1-methylimidazol-2-yl lithium with Cp2Zr(Cl)CH3 (6) gave the corresponding methyl(1-methyl-2-imidazolyl)zirconocene complex 7. Treatment of 7 with B(C6F5)3 (8) led to selective methyl abstraction. The resulting (imidazolyl)zirconocene cation 9 dimerized under the reaction conditions to yield the dinuclear imidazolyl bridged bis(zirconocene) dication complex 10 that was structurally characterized by X-ray diffraction and by DFT calculations.
Metallkomplexe mit biologisch wichtigen Liganden, CLI [1]. Metallorganische Komplexe mit R-3-(3-Pyridyl)alaninat
Authors: Ponikwar Walter , Beck Wolfgang
Published: August 2018

Reactions of chloro bridged complexes with R-3-(3-pyridyl)alanine afford the chelate complexes LnM[NH2CH(CO2)CH2C5H4NH+]Cl− (LnM = Ph3P(Cl)Pd, (tol3P)(Cl)Pd, (Ph-pyridyl)2Ir, Cp٭(Cl)Rh, Cp٭(Cl)Ir, (p-Cymol)(Cl)Ru) with protonated pyridine substituents. An analogous Cp٭Rh complex with 3-(2-pyridyl)alaninate was also obtained. Addition of base (NaOMe) to these complexes gives dimeric and trimeric complexes with coordination of the pyridine N atom.
Large Scale Synthesis of 4’-(4-Bromophenyl)-2,2’:6’,2”-terpyridine and Nature of the Mysterious Green By-product
Authors: Siemeling Ulrich , der Brüggen Jens Vor , Vorfeld Udo , Stammler Anja , Stammler Hans-Georg
Published: August 2018

4’-(4-Bromophenyl)-2,2’:6’,2”-terpyridine (5) was prepared on a large scale (up to 100 g batches) from 2-[3-(4-bromophenyl)-1-oxoprop-2-enyl]pyridine (3a) and N-[2-oxo-2-(2-pyridyl)- ethyl]pyridinium iodide (4). In the presence of substoichiometric amounts of 4, 1-[3-(4- bromophenyl)indolizin-1-yl-1-imino]-3-[4-bromophenyl]-1H-indolizinium iodide (6aI) was formed as an intensely coloured by-product. The synthesis of several related novel indolizinium derivatives is described, including 1-[3-(4-methylphenyl)indolizin-1-yl-1-imino]-3-[4-methylphenyl]-1Hindolizinium hexafluorophosphate (6cPF6), whose crystal structure has been determined.
R2Sn3 (R = La – Nd, Sm): A Family of Intermetallic Compounds with their Own Triclinic Structure
Authors: Fornasini Maria L. , Manfrinettib Pietro , Palenzonab Andrea , Dharc Sudesh K.
Published: August 2018

A new family of intermetallic compounds with stoichiometry R2Sn3 has been identified in the R-Sn system for R = La, Ce, Pr, Nd and Sm. All compounds have a new triclinic crystal structure: P1̄, a = 6.378(1), b = 8.422(1), c = 11.098(1) Å , α = 107.37(1)◦, β = 96.78(1)◦, γ = 100.03(1)◦ for Nd2Sn3. As a characteristic motif, the structure contains infinite chains of neodymium trigonal prisms centred by tin and sharing alternately a lateral face and an edge of a triangular face. Heat capacity measurements reveal that the compounds with R = Ce, Pr, Nd and Sm order magnetically and undergo multiple magnetic transitions; from entropy considerations it appears that the four symmetry in-equivalent Ce atoms in Ce2Sn3 and the Sm atoms in Sm2Sn3 are all in the trivalent state. The highest transition temperature of nearly 24 K is observed for Sm2Sn3. The magnetisation and heat capacity data of La2Sn3 indicate a superconducting transition with a Tc of about 2.5 K.
Crystal Structures of Heteronuclear Nickel(II)/Zinc(II) Doubly Oxygen Bridged Schiff-Base Complexes
Authors: Elmali Ayhan , Elerman Yalçın
Published: August 2018

{[μ-Bis(5-chlorosalicylidene)-1,3-propanediaminato]nickel(II)}dichlorozinc(II) ·2 dmf (dmf = dimethylformamide) 1 and {[μ-bis(5-bromosalicylidene)-1,3- propanediaminato]nickel(II)}- dichlorozinc(II) ·2 dmf (dmf) 2 were synthesized and their crystal structures determined. In both structures, the Ni(II) ions have a distorted octahedral geometry involving the N2O2 atoms of the Schiff-base ligands and two oxygen atoms of dimethylformamide (dmf) molecules. The coordination around the Zn(II) ions is distorted tetrahedral. The Ni···Zn distances are 3.132(1) Å for 1 and 3.122(1) Å for 2.
Manganiophosphonium-Salze: Synthese, Eigenschaften und Struktur von Komplexen des Typs [CpMn(CO)(NO)PPh2H]BF4 und [Cp′Mn(CO)(NO)PPh2R]X (R = H, CH3, {CpMn(CO)(NO)}; X = BF4, PF6)
Authors: Rudolph Stefan , Geicke Jan , Lorenz Ingo Peter , Seifert Thomas , Polborn Kurt , Hörner Manfredo
Published: August 2018

The reaction of [Cp′Mn(CO)2NO]X (Cp = C5H5, C5H4Me = Cp′; X =BF4, PF6) with PPh2H leads to the formation of the diphenylmanganiophosphonium salts [{CpMn(CO)NO}PPh2H]X, which can be deprotonated by DABCO to give the not isolable manganiophosphane {CpMn(CO)NO}PPh2. This reactive intermediate, however, can be methylated by MeI and CF3SO3Me or organometallated by C5H5Fe(CO)2Cl to yield the phosphonium salts [{Cp′Mn(CO)NO}PPh2Me]PF6 and [{Cp′Mn(CO)NO}PPh2{C5H5Fe(CO)2}]PF6, respectively. The methyl derivative is deprotonated by πBuLi to give the unstable methylene phosphorane {Cp′Mn(CO)NO}PPh2=CH2, an organometallated phosphorus ylide. The in situ from [{Cp′Mn(CO)NO}PPh2H]BF4 generated phosphane {Cp′Mn(CO)NO}PPh2 is oxidized by epoxycyclohexane to give the intermediate oxophosphorane {Cp′Mn(CO)NO}P(O)Ph2, which reacts with the still available starting material to yield the first dimanganiodiphenylphosphonium salt [{Cp′Mn(CO)NO}2PPh2]BF4. The compounds have been characterized by spectroscopic (IR, NMR, MS), analytical (C, H, N) and X-ray diffraction investigations ([{C5H5Mn(CO)NO}PPh2H]BF4, [{Cp′Mn(CO)NO}PPh2Me]BF6, [{Cp′Mn(CO)NO}2PPh2]-BF4).
Synthesis, Crystal and Magnetic Structure of the New Double Perovskite Ba2MnMoO6
Authors: Martínez-Lope M. J. , Alonso J. A. , Casais M. T.
Published: August 2018

We describe the preparation and characterization of a new double perovskite of formula Ba2MnMoO6. It has been obtained in polycrystalline form by thermal treatment, in a H2/N2 flow, of previously decomposed citrate precursors. This material has been studied by X-ray (XRD) and neutron powder diffraction (NPD): it crystallizes, at room temperature, in the cubic space group Fm3̄̄̄̄̄m, and shows an almost perfect ordering between Mn2+ and Mo6+ cations at the B substructure. Below TN = 10.8 K, it experiences a long range antiferromagnetic ordering that was followed from sequential NPD data. The low-temperature magnetic structure is defined by the propagation vector k = (1⁄2, 1⁄2, 1⁄2). The ordered magnetic moment of Mn is found to be 4.04(8) μB at 2 K, suggesting a divalent oxidation state for Mn cations, in a high spin t3
2ge2
g (S = 5/2) electronic configuration.
Teilweise Sauerstoff-Wanderung in der photochemischen Wolff-Umlagerung – α-Oxocarben-Oxiren-Isomerisierung oder intermolekularer Mechanismus?
Authors: Haiss Peter , Zeller Klaus-Peter
Published: August 2018

Crossover experiments between isotopomeric species of 2-diazo-1-oxo-1-phenylethane (18O, 13C, D) establish beyond doubt that the oxygen migration accompanying the photochemical Wolff rearrangement is not the result of intermolecular processes. This is in agreement with a carbenecarbene rearrangement via an intermediate oxirene in competition to the rearrangement into a ketene, as reason for the partial oxygen migration in the Wolff rearrangement products.
Dimorphism in Mercury(II) Iodate(V): Preparation and Thermal Behaviour of α- and β-Hg(IO3)2, and Single Crystal Structure Analysis of β-Hg(IO3)2
Authors: Weil Matthias
Published: August 2018

Mercury(II) iodate(V) is dimorphous and crystallizes in two polymorphs named α- and β - Hg(IO3)2. The α-modification was prepared by precipitation of a slightly acidified Hg(NO3)2 solution with an excess of an aqueous HIO3 solution; for the polycrystalline material unindexed powder data is given. Colourless to light-yellow single crystals of the β -modification, with an edge-length of up to 0.3 mm and a plate-like habit, were grown during hydrothermal treatment (220 °C, 10 d) of the polycrystalline precipitate. The crystal structure of β -Hg(IO3)2 was determined from single crystal X-ray data (space group P21 (no. 4), Z =2, a=5.7818(9), b=5.6077(10), c=8.9849(12) Å, β =102.890(2)°, 1668 structure factors, 83 parameter, R[F2 >2σ (F2)]=0.0175, wR(F2 all) = 0.0382) and is made up from trigonal pyramidal IO3 groups with an average I-O distance of 1.825 Å and distorted [HgO8] polyhedra with a mean Hg-O bond length of 2.537 Å as the main building units. Infinite zig-zag chains of cis-corner-sharing [HgO4/2O4/1] polyhedra extend parallel to [010]. The chains are connected by IO3 groups along the [100] direction to form layers parallel to the (001) plane. The three-dimensional framework is held together by weak intermolecular I-O interactions > 2.58 Å along the [001] direction. No α ↔ β phase transformation was detected upon heating. Both polymorphs decompose completely in an one-step mechanism around 500°C.
Photolysis of Naphthol Green B in Aqueous Solution. Photoreduction of Fe(III) Induced by Ligand-to-Metal Charge Transfer Excitation
Authors: Kunkely Horst , Vogler Arnd
Published: August 2018

The intense long-wavelength absorption of Naphthol Green B at λmax = 712 nm is assigned to a ligand-to-metal charge transfer (MLCT) transition. LMCT excitation of the complex in aqueous solution leads to the reduction of Fe(III) to Fe(II) with a quantum yield of ϕ = 1.14×10−3 at λirr = 577 nm.
Non-Stoichiometric Monoclinic Cr5Se8 Prepared at High-Pressure and High-Temperature and the Crystal Structure Refined from Rietveld Data
Authors: Huppertz H. , Lühmann H. , Bensch W.
Published: August 2018

The non-stoichiometric chromium selenide Cr5.095(5)Se8 was prepared under high-pressure hightemperature conditions. The structure was refined from X-ray powder data with the Rietveld method in the non-conventional monoclinic space group F2/m, a = 12.2992(2), b = 7.12753(12), c = 11.4486(2) Å , β = 90.927(1)° and V = 1003.49(3) Å3. Three of the four unique Cr sites are fully occupied, and one site is only partially occupied. The structure may be viewed as being composed of alternating full and metal deficient layers which are oriented perpendicular to the crystallographic c axis of the pseudo-hexagonal unit cell. All Cr atoms are in an octahedral environment of six Se atoms. The CrSe6 octahedra of neighbouring layers share common faces whereas the octahedra with layers are joined by common edges. As a result short Cr-Cr distances of 2.867(3) and 2.951(6) Å are found across common faces while Cr-Cr separations between CrSe6 octahedra sharing edges are significantly longer. From a formal point of view charge balance requires a formulation as Cr4+
0.715Cr3+
4.38Se8. On the basis of the distortion of the CrSe6 octahedra the Cr4+ ions are mostly located on two different sites.
SiF-NH-Funktionelle Cyclodisilazane – Synthese und Reaktivität / SiF-NH-Functional Cyclodisilazane – Synthesis and Reactivity
Authors: Reiche Clemens , Klingebiel Uwe , Noltemeyer Mathias
Published: August 2018

Dichlorosilanes with bulky substituents R(Me3C)SiCl2 react with liquid ammonia to give geminal silyldiamines [R(Me3C)Si(NH2)2, 1: R = CH2 Me, 2: R = CHMe2]. In the reaction of the monolithium derivatives of these compounds with halosilanes 1-amino-1.3-disilazanes are obtained [(NH2)(Me3C)RSi-NH-SiR1R2R3; 3: R = CMe3, R1 = R2 = R3 = Me; 4: R = R1 = CMe3, R2 = R3 = Me; 5: R = R1 = R2 = CMe3, R3 = H; 6: R = R1 = CMe3, R2 = Me, R3 = F; 7: R = CHMe2, R1 = R2 = R3 = Me]. If monolithiated diamines are treated with trifluorosilanes cyclisation occurs to give (NH-Si(CMe3)2-NH-SiFR)cyclodisilazanes [R = N(SiMe3)(CMe3) (8); R = N(SiMe2CMe3)2 (9)]. 50% of the educts are recovered. The spirocyclic compound 10 is isolated from the reaction of the dilithiated 1-amino-1.3-disilazane 3 with F3SiN(SiMe2CMe3)2. NH-SiF-Functional cyclodisilazanes can be obtained in the reaction of the dilithium derivative of compound 4 with trifluorosilanes [(N(SiMe2CMe3)-Si(CMe3)2-NH-SiFR), R = Ph (11); R = CMe3 (12)]. The lithium derivative of 12 crystallises with TMEDA as adduct 13. In the reaction of the lithiated compound 12 with Me3SiCl, LiCl elimination and substitution of the N-atom is observed (14). The treatment of 13 with PhCHO leads to a 1.3-diaza-5-oxa-2.4-disila-cyclohexane (15 a, b). Starting from lithiated 12 the methoxysubstituted cyclodisiloxane 16 is accessible in the reaction with MeOH. As result of its reactivity towards Me2SiF2 the fluorosilyl-substituted cyclodisilazane 17 is obtained. Crystal structures of 9-11 and 13 have been determined.
Synthesis, Electronic Spectra and Solvent-Induced Reversible Dissociation of Diphosphine(hexafluoroacetylacetonato)copper(I) Complexes
Authors: Pawlowski Valeri , Strasser Andreas , Vogler Arnd
Published: August 2018

The complexes CuI(P-P)(hfac) with P-P = 1,2-bis(diphenylphosphino)ethane (diphos), 1,3-bis-(diphenylphosphino)propane (prophos), 2,2’-bis(diphenylphosphino)-1,1’-binaphthyl (binap) and hfac = hexafluoroacetylacetonate were synthesized and spectroscopically characterized. In the solid state or in solutions of non-polar solvents these compounds are yellow owing to a long-wavelength (hfac− →P-P) ligand-to-ligand charge transfer absorption. In coordinating solvents such as CH3CN the complexes undergo a reversible dissociation according to the equation:

Cu(P-P)(hfac) + n CH3CN ⇌ [Cu(P-P)(CH3CN)n]+hfac−.

While the complexes are not luminescent the ion pairs [Cu(P-P)(CH3CN)n]+hfac− are emissive at 77 K. The cations and the anions show separate emissions as indicated by the excitation spectra.
Cadmium Carboxylate Chemistry: Preparation, Crystal Structure, and Thermal and Spectroscopic Characterization of the One-dimensional Polymer [Cd(O2CMe)(O2CPh)(H2O)2]n
Authors: Stamatatos Theocharis C. , Katsoulakoua Eugenia , Nastopoulos Vassilios , Raptopoulou Catherine P. , Manessi-Zoupa Evy , Perlepes Spyros P.
Published: August 2018

Compound [Cd(O2CMe)(O2CPh)(H2O)2]n (1) was initially obtained in a serendipitous way during efforts to prepare a CdII /PhCO2 −/bepy complex (bepy = 2-benzoylpyridine). With the identity of 1 established by single-crystal X-ray crystallography, a rational preparative route to this complex was designed and carried out by reacting Cd(O2CMe)2·2H2O with a slight excess of PhCOOH in MeCN under reflux. The crystal structure of 1 consists of isolated zig-zag chains. The CdII atom is coordinated to five carboxylate and two aqua oxygen atoms creating a distorted, capped trigonal prismatic coordination polyhedron. The acetate group exhibits the η1:η2:μ2 coordination mode, while the benzoate ligand is chelating. There is an extensive hydrogen-bonding network which reinforces the chains and also links them generating sheets. The new complex was characterized by IR, far-IR, Raman, CP MAS and solution 113Cd NMR spectroscopy. The spectroscopic data are discussed in terms of the nature of bonding and the known structure. An anhydrous compound with the empirical formula Cd(O2CMe)(O2CPh) was isolated during the thermal decomposition of 1; the vibrational study of this thermally stable intermediate supports an 1D polymeric structure with 6-coordinate CdII ions.
Electrodeposition and Corrosion Resistance of Zn-Pd Alloy from the ZnCl2-EMIC(1-ethyl-3-methylimidazolium chloride)-PdCl2 Room Temperature Molten Salt
Authors: Hsu Hsin-Yi , Yang Chao-Chen
Published: August 2018

Electric conductivities of 50-50 mol% ZnCl2-EMIC and its mixtures with 0.6714 mol% PdCl2 room-temperature molten salts (RTMS) have been measured by a computerized system based on a d.c. four-probe method. The conductivity of the former is greater than that of the latter. These conductivities are well fitted by Arrhenius equations and the activation energies are calculated to be 25.22 and 26.28 kJ/mol, respectively. Cyclic voltammetry for the ZnCl2-EMIC-PdCl2 melt has been performed on Pt and Cu working electrodes. The cathodic reduction waves of Pd2+ and Zn2+ species and the oxidation waves for Zn-Pd alloys rich in Zn and Pd have been observed for the cyclic voltammograms on the Pt working electrode. The deposition potentials have been measured to be −0.7 V and −1.3 V on the Cu substrate. The morphology and composition of the electrodeposited layers obtained under different conditions have been analyzed by SEM and EDS, respectively; layers with a finer (about 300 - 500 nm), denser and higher Pd content have been obtained by pulse plating on the Cu sheet at ton/toff = 3/1 under −0.7 V at 80 °C. The XRD patterns also reveal that the structure of these deposited layers can be regarded as amorphous. Tafel polarization curves of the electrodeposited layers in 3.5 wt% NaCl solution have been drawn. The results indicate that the Zn-Pd alloy deposits have much higher corrosion resistance and protection efficiency than the Zndeposited layer; the corrosion potentials shift positively by about 700 ∼ 950 mV. Furthermore, the pulse plating has a better performance than the direct current plating, and the reason is discussed.
Azide und Cyanamide – ähnlich und doch anders/Azides and Cyanamides – Similar and Yet Different
Authors: Reckeweg Olaf , Simon Arndt
Published: August 2018

The crystal structures of LiN3*H2O (P63/mcm (No. 193), Z = 6; 924.01(13); 560.06(7) pm); NH4N3 (Pmna (No. 53), Z =4; a=889.78(18), b=380,67(8), c=867.35(17) pm); Ca(N3)2 (Fddd (No. 70), Z = 8; a=595.4(2), b=1103.6(5), c=1133.1(6) pm), Sr(N3)2 (Fddd (No. 70), Z =8; a= 612.02(9), b = 1154.60(18), c = 1182.62(15) pm); Ba(N3)2 (P21/m (No. 11), Z = 2; a = 544.8(1), b = 439.9(1), c = 961.3(2) pm, β = 99.64(3)°) and TlN3 (I4/mcm (No. 140), Z = 2; 618.96(9); 732.71(15) pm) have been either determined for the first time or redetermined by X-ray diffraction on single crystals. The afore mentioned compounds, AN3 (A = Na, K, Rb, Cs), M(N3)2 · 2.5 H2O (M = Mg, Zn) and the cyanamides Li2CN2, CdCN2 and CuCN2 were investigated by Raman and IR spectroscopy (KBr technique). Structural features and spectroscopic data of azides and cyanamides from this work and from literature are listed and compared.
Synthesis and Characterization of Metal Carbonyls [M(CO)6(M =Cr, Mo, W), Re(CO)5Br, Mn(CO)3Cp] with 2-Hydroxy-1-napthaldehyde Ethanesulfonylhydrazone (nafesh)
Authors: Senturk Ozan Sanli , Serta Sema , Özdemirc Ümmuhan
Published: August 2018

Five new complexes, M(CO)5(nafesh) (M = Cr (1), Mo (2), W (3)), Re(CO)4Br(nafesh) (4) and Mn(CO)3(nafesh) (5) have been synthesized by the photochemical reaction of metal carbonyls M(CO)6 (M = Cr, Mo, W), Re(CO)5Br, and Mn(CO)3Cp with 2-hydroxy-1-napthaldehyde ethanesulfonylhydrazone (nafesh). The complexes have been characterized by elemental analysis, EI mass spectrometry, FT-IR, 1H NMR spectroscopy. The spectroscopic studies show that nafesh behaves as a monodentate ligand coordinating via imine N donor atom in M(CO)5(nafesh) (M = Cr, Mo, W) and Re(CO)4Br(nafesh) and as tridentate ligand in Mn(CO)3(nafesh).
A New Pyranoacridone Alkaloid from the Bark of Medicosma subsessilis (Rutaceae)
Authors: Minh Nguyen Tuan , Michel Sylvie , Tillequin Francçois , Litaudon Marc , Sévenet Thierry , Lallemand Marie-Christine
Published: August 2018

The alkaloids evolitrine, acronycidine, melicopine, melicopidine, normelicopine, normelicopidine, acronycine, noracronycine, 12-desmethylacronycine, (+)-cis-1,2-dihydroxy-1,2-dihydroacronycine, and (-)-trans-1,2-dihydroxy-1,2-dihydroacronycine were isolated from Medicosma subsessilis bark, together with the new 1-oxo-2-hydroxy-1,2-dihydro-12-desmethylnoracronycine. The structure of the latter compound was elucidated on the basis of spectral data and partial synthesis.
A New Eudesmane Derivative from Leontodon tuberosus
Authors: Spitaler Renate , Ellmerer Ernst-P. , Zidorn Christian , Stuppner Hermann
Published: August 2018

Besides the known compounds 2,4,6-trihydroxyacetophenone 4-O-β -D-glucopyranoside and syringaresinol 4’-O-β -D-glucopyranoside, the novel sesquiterpenoid 1,2-dehydro-3-oxocostic acid β - D-glucopyranoside ester was isolated from Leontodon tuberosus L. and its structure established by mass spectrometry and 1D- and 2D-NMR spectroscopy. Additionally, a number of fatty and phenolic acids was identified in the crude methanolic extract by HPLC-DAD and HPLC-MS. The chemosystematic impact of the new sesquiterpenoid is discussed briefly.
Polyol Metal Complexes, 45 [1]. D-Glucopyranosides as Ligands in Nickel Complexes
Authors: Herdin Sven , Kettenbach Gerhard , Klüfers Peter
Published: August 2018

Crystalline nickel complexes with dianionic glucopyranoside ligands have been obtained by the reaction of methyl-D-glucopyranoside (Me-β -D-Glcp) or sucrose (Suc) with the cellulose solvent Ni-tren, an aqueous solution of [(tren)Ni(OH)2], tren = tri(2-aminoethyl)amine. Crystals of a nickel complex of α,α-trehalose (α,α-Tre) form after the reaction of the disaccharide with Ni-Me3 tren, the N,N′,N″-trimethyl analogue of Ni-tren. The metal-binding site is the O3,O4 diolate in [(tren)Ni(Me-β-D-Glcp3,4H−2)] · 5.5H2O; in [(tren)Ni(Suc2’,3’H−2)] · 6H2O, hydrogen-bond-supported O2,O3 chelation in the glucose part of the disaccharide is observed. The same metal-binding site as sucrose is exhibited by α,α-trehalose in [(tren)Ni(α,α-Tre2,3H−2)] ・ 5H2O but without the support by an intramolecular hydrogen bond.
Pubesamides A, B, and C, Three New N-Benzoyltyramide Derivatives Isolated from Casimiroa pubescens
Authors: García-Argáez Aída N , González-Lugo Nadia M. , Parra-Delgado Hortensia , Martínez-Vázquez Mariano
Published: August 2018

Three new N-benzoyltyramides derivatives named pubesamides A, B and C together with the known skimmianine, β -sitosterol and daucosterol were isolated from seeds of C. pubescens. Their structures were determined by spectroscopic data.
Synthesis and Structure of RhMg3 and Ir3Mg13
Authors: Hlukhyy Viktor , Rodewald Ute Ch. , Hoffmann Rolf-Dieter , Pöttgen Rainer
Published: August 2018

The binary transition metal magnesium compounds RhMg3 and Ir3Mg13 have been synthesized from the elements in sealed niobium tubes and investigated on the basis of X-ray powder and single crystal data: Cu3P type, P63cm, a = 790.5(4), c = 825.6(3) pm, wR2 = 0.0244, 344 F2 values, 27 variable parameters for RhMg3, and R3̅c, a = 1607.0(2), c = 844.88(9) pm, wR2 = 0.0535, 656 F2 values, 29 variable parameters for Ir3Mg13. The rhodium atoms in RhMg3 have coordination number 11. These polyhedra show an AB AB stacking sequence like in the hexagonal close-packed structure. The crystal chemical relation of the Cu3P type structure of RhMg3 with the aristotype Na3As (IrAl3) is discussed on the basis of a group-subgroup scheme. Ir3Mg13 crystallizes with a new complex structure type with coordination numbers of 11, 14, 15, 14, and 12 for the Ir, Mg1, Mg2, Mg3, and Mg4 atoms, respectively
Preparation, Crystal Structure at 298 and 90 K and Phase Transition in (C2H5NH3)2[SbBr5] Studied by the Single Crystal X-Ray Diffraction Method
Authors: Bujak Maciej , Zarychta Bartosz , Kobel Aleksandra , Zaleski Jacek
Published: August 2018

The reaction of antimony(III) oxide with ethylamine, in molar ratios from 1:1 to 1:10, in concentrated hydrobromic acid leads to the formation of one product - bis(ethylammonium) pentabromoantimonate( III). The structure of (C2H5NH3)2[SbBr5] was determined at 298 and 90 K, below and above the phase transition that occurs at about 158.5 K. The orthorhombic system was found in both phases, space groups Cmca and Pbca at 298 and 90 K, respectively. At both temperatures the structure consists of [SbBr6]3− octahedra connected via cis bromine atoms forming one-dimensional zig-zag [{SbBr5}2−]n chains. The ethylammonium cations fill the space between polyanionic chains. The organic and inorganic substructures are held together by a system of N(-H)···Br interactions. Their influence on the deformation of [SbBr6]3− octahedra is well reflected in differences in the corresponding Sb-Br bond lengths and Br-Sb-Br angles in both phases. The phase transition is of the first order and the order-disorder type. It is related to changes in the molecular dynamics of the ethylammonium cations. In the low-temperature phase the organic cations are ordered, while at 298 K both crystallographically independent cations are disordered. The type of disorder is realized by the presence of two positions of the methyl carbon atoms
Isolation of Bioactive Compounds from Aspergillus terreus
Authors: Choudhary Muhammad I. , Musharraf Syed G. , Mukhmoor Talat , Shaheen Farzana , Ali Shamsher , Rahman Atta-ur
Published: August 2018

A new metabolite, 6-(4’-hydroxy-2’-methyl phenoxy)-(-)-(3R)-mellein (1) was isolated from the ethyl acetate extract of Aspergillus terreus culture medium along with three known isocoumarin derivatives, (-)-(3R)-6-methoxymellein (2), (-)-(3R)-6,7-dimethoxymellein (Kigelin) (3) and (3R, 4R)-6,7-dimethoxy-4-hydroxymellein (4). Metabolites 1 and 4 showed significant activity against human pathogenic dermatophytes, Microsporum canis and Trichophyton longifusus. Metabolite 1 also exhibited potent antioxidant activity. The structures of metabolites were characterized on the basis of spectroscopic techniques. 13C NMR data of metabolites 2 - 4 are also being reported for the first time
Enantioselective Synthesis of Epi-Emetine Analogues: Control of the Facial Selectivity in a Three-Component Domino Knoevenagel-Hetero-Diels-Alder Reaction*
Authors: Tietze Lutz F. , Rackelmann Nils
Published: August 2018

The domino Knoevenagel-hetero-Diels-Alder reaction of the aldehyde rac-8, Meldrum’s acid 2 and enol ether 3 leads to the cycloadduct rac-17 as the main product which in a second domino process was transformed into the benzoisoquinolizidine rac-18 by solvolysis, hydrogenolysis, condensation and hydrogenation; rac-18 was used as a substrate for the synthesis of the two diastereomeric epiemetine analogues 9 and 10 with > 96% ee (9) and 80% ee (10), respectively, by condensation with the phenylethylamine 23, Bischler-Napieralski reaction and “enantioselective” hydrogenation using the chiral catalyst (R,R)-26.
Dinuclear Ruthenium(I)Triazenide Complexes as Catalysts for Carbenoid Cyclopropanation Reactions
Authors: Leger Claus-Dieter , Maas Gerhard
Published: August 2018

The ability of ruthenium(I) triazenide complexes [Ru(CO)3(ArNNNAr)]2 (Ar = C6H4-4-X, X = CH3, Cl, Br) to catalyze the cyclopropanation of alkenes with methyl diazoacetate is investigated. With terminal alkenes (styrene, ethyl vinyl ether, 1-hexene), the cyclopropanecarboxylic esters are formed in good to high yield and with an E : Z diastereoisomer ratio of about 1.0 in most cases. 2-Methyl-2-butene is cyclopropanated in low yield but with a syn-selectivity up to 90:10.
Hexaethyl-2,4-dicarba-nido-hexaborane(8), Deprotonation and Complexation Studied by NMR Spectroscopy and Density Functional Theory (DFT) Calculations
Authors: Wrackmeyer Bernd , Schanz Hans-Jörg
Published: August 2018

Deprotonation of hexaethyl-2,4-dicarba-nido-borane(8) 2 leads first to the hexaethyl-2,4-dicarbanido- borate(1−) 3, and further deprotonation, using BuLi/KOtBu, gives the hexaethyl-2,4-dicarbanido- hexaborate(2−) 4. The reaction of 3 with FeCl2 affords the commo-ferracarborane [Fe(Et6-2,4- C2B4H)2] 5, and the analogous reaction of 4 leads to the anionic sandwich complex [Fe(Et6-2,4- C2B4)2]2− 6 which can be protonated to give 5. The complex 5 contains two hydrido ligands, each bridging the iron and two boron atoms. Reactions were monitored and the products were characterised by 11B NMR spectroscopy in solution. The geometries of the carboranes, the borates (all unsubstituted and permethyl-substituted) and the iron complexes (all unsubstituted) were optimised by DFT methods [B3LYP/6-311+G(d,p) or B3LYP/6-31+G(d)], and the relevant NMR data [chemical shifts δ11B, δ13C, δ57Fe, and coupling constants 1J(13C,1H), 1J(11B,1H), 1J(57Fe,1H), 1J(57Fe,11B)] were calculated at the same level of theory.
Phase Transitions and Distortion of [BiCl6]3– Octahedra in (C3H5NH3)3[BiCl6] – DSC and Single-Crystal X-Ray Diffraction Studies
Authors: Zarychta Bartosz , Bujak Maciej , Zaleski Jacek
Published: August 2018

The DSC diagram of tris(allylammonium) hexachlorobismuthate(III), (C3H5NH3)3[BiCl6], revealed three anomalies at 152, 191 and 299 K. The structure of the salt was determined at 200 and 315 K, below and above the high-temperature phase transition at 299 K. In both phases the crystals are monoclinic. At 200 K the space group is C2/c whereas at 315 K it is C2/m. The structures, at both temperatures, are composed of [BiCl6]3− octahedra and allylammonium cations. The organic and inorganic moieties are attracted to each other by a network of the N-H. . .Cl hydrogen bonds. The relationship between corresponding parameters of the unit cells has been found. The phase transition at 299 K, of the order-disorder type, is attributed to the ordering of one non-equivalent allylammonium cation in the low-temperature phase.
Carbazolylsilane: Synthese und Kristallstrukturen / Carbazolylsilanes: Synthesis and Crystal Structures
Authors: Liebau Verena , Noltemeyer Mathias , Magull Jörg , Klingebiel Uwe
Published: August 2018

Carbazole reacts with n-BuLi and fluorosilanes to give the lithium carbazolide (1) which crystallizes as a dimer from THF. In the reactions of 1 and difluorosilanes, F2SiR2, the carbazolylsilanes C12H8N-SiFR2 (2 - 4 R = Me (2), i Pr (3), t-Bu (4)), are obtained. Bis(carbazolyl)silanes, (C12H8N)2SiFR, are formed in the reaction of 1 with trifluorosilanes, F3SiR, in a molar ratio of 2:1, R = t-Bu (5), Ph (6), Me (7). Using F3SiMe and 1 in a molar ratio of 1:3 the tris(carbazolyl)silane (C12H8N)3SiMe (8) is isolated. The carbazolylfluorosilane 3 reacts with n-BuLi to give 1 and n-butyldiisopropylfluorosilane, or with lithium pyrrolide to give carbazolyl(-diisopropyl)pyrrolylsilane (9). Lithiumpyrrolide cleaves the Si-NC12H8-bond of 9 and forms the diisopropyl-bis(pyrrolyl)silane 10.

The crystal structures of 5, 6 and 7 have been determined and are discussed.
A New Triterpenoid Saponin and Two Neolignans from Ligularia veitchiana
Authors: Zhu Hui , Tu Pengfei
Published: August 2018

Phytochemical investigation of the rhizomes and roots of Ligularia veitchiana afforded a new triterpenoid saponin and two known neolignans named liguveitoside B (1), citrusin A (2) and citrusin B (3), respectively. This is the first demonstration of the occurrence of a 8-O-4’ neolignan and the second report on the isolation of triterpenoid saponin in the genus Ligularia. Their structures were elucidated on the basis of spectral data, particularly HSQC, HMBC and NOE experiments. Compound 1 exhibited weak cytotoxicity against a human acute promyelocytic leukemia cell-line (HL-60).
Two New Tirucallane Triterpenes with Six-Membered Hemiacetal from Amoora dasyclada
Authors: Yang Shu-Min , Ding Li , Wu Shao-Hua , Ma Yun-Bao , Luo Xiao-Dong , Wu Da-Gang
Published: August 2018

Two novel tirucallane derivatives, 3α,21β ,25-triol-tirucalla-21,24-epoxy-23-one (1) and 21β ,25- diol-tirucalla-21,24-epoxy-3,23-dione (2), were isolated from Amoora dasyclada. Their structures were identified by spectroscopic and chemical means.
Crystal Structure of N-3-Pyridinyl-methanesulfonamide and trans-Diiodobis(N-3-pyridinyl-methanesulfonamide)platinum(II)
Authors: Dodoff Nicolay I. , Varga Richard A. , Kovala-Demertzi Dimitra
Published: August 2018

Crystals of N-3-pyridinyl-methanesulfonamide, PMSA (monoclinic, P21/c, a = 5.6436(7), b = 33.875(4), c = 8.3356(10) Å , β = 96.885(2)°) contain two non-equivalent molecules differing considerably in their conformations. The structure is stabilized by a network of hydrogen bonds, the strongest one being between the pyridine N atom and the sulfonamide H atom. Crystals of trans-[Pt(PMSA)2I2] (monoclinic, C2/c, a = 22.912(2), b = 5.2397(5), c = 17.3376(17) Å , β = 92.631(2)◦) contain centrosymmetric complex molecules in which PMSA is coordinated via the pyridine N atom, and Pt has a planar coordination. A system of hydrogen bonds of the types N−H· · ·O and C−H· · ·O links the complex molecules.
A New Ternary Arsenide LaNi5As3: Preparation and Crystal Structure
Authors: Babizhetskyy Volodymyr , Guérin Roland , Simon Arndt
Published: August 2018

The title compound was prepared from the elements by arc-melting followed by annealing in silica tubes at 1070 K for 3 months. The orthorhombic structure of LaNi5As3 was solved and refined from X-ray single crystal data: space group Pnma, a = 11.179(2), b = 3.9133(5), c = 24.443(3) Å , Z = 8, R = 0.040, Rw = 0.039 for 1045 unique reflections with I > 2σ (I) and 110 parameters. It is a new structure type, which can be described by condensed units of trigonal prisms around the arsenic atoms linked together to infinite zigzag chains. The structural features of LaNi5As3 are discussed in comparison with some representatives of a large family of structures with a metal/non-metal ratio equal or close to 2:1.
1,2-Deoxygenation of vic-Dihydroxyindenoimidazoles: Optimization of a Novel Deoxygenation Reagent
Authors: Hemmerling Hans-Jörg , Merschenz-Quack Angelika , Wunderlich Hartmut
Published: August 2018

Treatment of vic-dihydroxyindeno[1,2-d]imidazoles with N,N,N’,N’-tetraalkyl sulfurous diamides yields indeno[1,2-d]imidazoles by deoxygenation. Isochromeno[3,4-d]imidazoles are formed as byproducts. An X-ray crystal structure analysis confirmed the structure of deoxygenated products. The ratio of products depending on the reaction conditions was analyzed. A mechanism of the reaction is discussed.
Macrocyclic Gold(I) Complexes with Bridging Diacetylide and Diphosphine Ligands
Authors: Hunks William J. , Jennings Michael C. , Puddephatt Richard J.
Published: August 2018

The new dialkynyldigold(I) complexes [Ar(OCH2C≡CAu)2]n {Ar = 1,4-C6H4(CMe2-4-C6H4)2, 4,4’-C6H4C6H4 and 1,5-C10H6} react with diphosphines LL = Ph2P(CH2)nPPh2 (n = 1 to 6) and trans-Ph2PCH=CHPPh2 to give luminescent macrocyclic digold(I) or tetragold(I) complexes with bridging diphosphine and diacetylide ligands. The digold(I) complex [1,4-C6H4(CMe2-4- C6H4OCH2C≡CAu)2(μ-LL)], with LL = trans-Ph2PCH=CHPPh2, forms a 28-membered ring, and the rings associate through aurophilic bonding in the solid state. In contrast, the tetragold(I) complex [4,4’-C6H4C6H4(OCH2C≡CAu)2(μ-LL)], with LL = Ph2PCH2PPh2, forms a more rigid 42-membered ring.