bluuebunny/crossref_metadata_2025 huggingface dataset:
New One- and Two-Dimensional Heterometallic Cu/Cd Halogeno or Thiocyanato Bridged Coordination Polymers Synthesized Directly from Elemental Copper and Cadmium Oxide in the Presence of Ethylenediamine
Authors: Pryma Oksana V. , Petrusenko Svitlana R. , Kokozaya Vladimir N. , Shishkin Oleg V. , Zhigalko Marina V. , Linert Wolfgang
Published: August 2018

Three heterometallic Cu/Cd complexes [Cu(en)2CdBr4]·dmso (1), [Cu(en)2CdI4]·dmf (2) and [{Cu(en)2}3Cd(NCS)6](NCS)2 (3) have been synthesized by means of an open-air reaction of unactivated copper powder, cadmium oxide, NH4X (X = Br, I, NCS) and ethylenediamine in non-aqueous solvents, like dmso, dmf and CH3OH. The selection of a counter-anion in the initial ammonium salt provides a facile approach to the controlled assembly of one- or two-dimensional extended networks. Crystallographic investigations reveal that 1 and 2 possess 1D structures via semi-coordination (Cu2+ . . .X) and hydrogen bonds (NH2 . . . OSolv) forming chains with a zigzag arrangement of copper and cadmium atoms. In complex 3 the cadmium atom of each Cd(NCS)6
4− anionic block forms bridges with Cu(II) ions via the sulfur atoms of thiocyanate groups to give 2D polymeric sheets, featuring two different ring sizes, one a 32-membered ring [Cu4Cd4(μ−SCN−S,N)8] and the other a 16- membered ring [Cu2Cd2(μ−SCN−S,N)4]. It is noteworthy, that 3 shows a quite rare Cd(NCS)6
4− fragment with N-bonded thiocyanate groups.
(3-Iminio-1-propenyl)oxy-borates: New Acyclic Betaines from Enaminocarbonyl Compounds and Boron Trifluoride or Triphenylboron – Synthesis, Crystal Structure Analysis, and Quantum Chemical Calculations
Authors: Nikolai Joachim , Taubmann Gerhard , Maas Gerhard
Published: August 2018

Adducts of various acyclic enaminoketones and enaminoaldehydes with the Lewis acids boron trifluoride and triphenylboron were prepared. The adducts were characterized by NMR (1H, 13C, 11B) and IR spectroscopy, FAB-MS, and X-ray crystal structure analysis of the adducts of (E)-3- diethylamino-3-phenyl-2-propenal with BF3 (4a) and BPh3 (5a), respectively. The adduct formation occurs at the oxygen atom of the enaminocarbonyl compound and gives rise to a betainic structure with expressed equalization of the bond orders in the enaminocarbonyl moiety. The gas-phase structures of complexes 4a and 5a and of the corresponding free enaminoaldehyde were determined computationally by RHF and DFT methods, and a Natural Bond Orbital (NBO) analysis was undertaken.
Structural Investigation of a Configurationally Stable Seven-Membered Bridged Biaryl of Relevance for Atroposelective Biaryl Syntheses*
Authors: Bringmann Gerhard , Pfeifer Robert-Michael , Rummey Christian , Pabst Thomas , Leusser Dirk , Stalke Dietmar
Published: August 2018

The atroposelective ring opening of lactone-bridged biaryl systems is the key step in the total synthesis of a series of axially chiral biaryl natural products and useful reagents or catalysts for asymmetric synthesis. For a more in-depth understanding of the mechanism and stereochemical course of this remarkable cleavage reaction, a seven-membered ether analog of such useful biaryl lactones has been investigated structurally, both experimentally, by X-ray diffraction analysis, and by ab initio calculations (B3LYP/6-31G*). In a nearly perfect agreement, both methods show that these seven-membered bridged biaryls do not constitute helicene-like distorted molecules, but ‘true’ biaryls, whose sufficiently long lactone or ether bridge allows the two aromatic systems to adopt a large dihedral angle to each other, without any noticeable deviation from planarity for the two aromatic systems - in contrast to related six-membered analogs, which can rather be considered as helicene-like twisted polycyclic systems.
Atomvolumen, Packungsdichte und chemische Bindung in festem Iod unter Druck / Atomic Volume, Packing Density and Chemical Bonding in Solid Iodine under Pressure
Authors: Trömel Martin , Hübner Sven , Taxer Karlheinz
Published: August 2018

The volume changes of solid iodine under pressure are discussed with respect to the packing density of the atoms and to valence. The packing density of solid iodine which is 0.805 under ambient pressure increases to 0.976 in monoatomic iodine-II, 0.993 in iodine-III, and 1 in fcc iodine-IV. Simultaneously, the valence increases from 1 in the free molecule to 1.78 in the crystal structure under ambient pressure, 2.72 - 2.81 in iodine-II, 2.86 - 2.96 in iodine-III, and 3 in fcc iodine-IV. The valence then remains constant up to about 180 GPa and rises moderately to 3.15 at the highest investigated pressure of 276 GPa. Parameters for calculating bond numbers, valences and atomic volumes of densely packed halogens, hydrogen, oxygen, and nitrogen are given.
Ternary Rare Earth Metal Silicides RE2RE’3Si4 with Orthorhombic Sm5Ge4 or Tetragonal Zr5Si4 Type Structure
Authors: Rodewald Ute Ch , Heying Birgit , Johrendt Dirk , Hoffmann Rolf-Dieter , Pöttgen Rainer
Published: August 2018

Ternary silicides RE2RE′3 Si4 (RE = La, Ce; RE′= Y, Lu) were synthesized by arc-melting of the elements. Single crystals were grown by annealing the arc-molten buttons slightly below the melting points in water-cooled silica tubes in an induction furnace. Five silicides RE2RE3′Si4 were investigated by X-ray powder and single crystal diffraction: Zr5Si4 type, P41212, a = 779.4(3), c = 1441.3(9) pm, wR2 = 0.072, 1806 F2 values, 45 variables for La1.72(4)Y3.28(4)Si4, P43212, a = 769.92(7), c = 1412.3(1) pm, wR2 = 0.079, 1846 F2 values, 45 variables, BASF = 0.36(4) for La1.72(2)Lu3.28(2)Si4, P41212, a = 778.6(1), c = 1433.9(3) pm, wR2 = 0.054, 1910 F2 values, 46 variables, BASF = 0.34(4) for Ce1.82(6)Lu3.18(6)Si4, P43212, a = 778.8(3), c = 1436.0(10) pm, wR2 = 0.166, 1916 F2 values, 45 variables for Ce1.71(7)Y3.29(7)Si4, and Sm5Ge4 type, Pnma, a = 749.2(2), b = 1484.2(7), c = 780.3(2) pm, wR2 = 0.070, 1956 F2 values and 49 variables for Ce1.47(3)Y3.53(3)Si4. The local coordinations of both structure types are very similar, i. e. CN 18, 16, and 14 coordination polyhedra for the RE1, RE2, and RE3 atoms. The main structural motif is the eightfold coordination of the RE3 positions by rare earth metal atoms. These slightly distorted RERE’8 cubes are condensed via common corners (Zr5Si4 type) or via common edges (Sm5Ge4 type). All silicon atoms in these silicides form Si2 pairs at Si-Si distances ranging from 254 to 258 pm. DFT band structure calculations confirm the metallic character of both silicides and the trivalent state of cerium in Ce5Si4. The COHP analysis (Crystal Orbital Hamilton Population) of the Si-Si bonds shows a significant occupation of Si-Si antibonding orbitals, which is partially compensated by a Si-Si π*,σ*Y-4d (Ce-5d) back donation.
Four Isotypic Highly Coordinated Lanthanide Complexes of the Tripodal Ligand Bis[(2-pyridyl)methyl][(1-methylimidazol-2-yl)methyl]amine
Authors: Merkel Michael , Pascaly Matthias , Köster Christian , Krebs Bernt
Published: August 2018

The Ln(III) complexes (Ln = Pr, Nd, Sm and Tb) of the tripodal ligand bis[(2-pyridyl)methyl][(1- methylimidazol-2-yl)methyl]amine (bpia) have been synthesized and characterized by single crystal X-ray structure determination as well as vibrational spectroscopy. The coordination spheres of the lanthanide cations are completed by three chelating nitrate anions yielding neutral complexes with a tenfold coordination of the metal ions. All four compounds are found to be isotypic, crystallizing in space group P1̄ (No. 2) with Z = 2. On comparing the IR-spectra of the new complexes to the spectra of the free ligands a shift to higher wave numbers is observed for corresponding bands in both, bpia and nitrate ligands.
Synthesis and Structure of Sodium Tetraoxo Nitrido Molybdate, Na5MoO4N
Authors: Arumugam Nachiappan , Peters Eva M. , Jansen Martin
Published: August 2018

The new oxynitride of molybdenum, Na5MoO4N was prepared from stoichiometric mixtures of the starting materials MoO2, Na2O2 and NaN3 which were heated in a special regime up to 500°C, and cooled down slowly. Its crystal structure was solved and refined from single crystal data (orthorhombic, Cmcm, a = 991.1(2), b = 574.3(1), c = 1067.7(2) pm, R1 = 0.0153, wR2 = 0.0427). The structure consists of isolated [MoO4N]5− rectangular pyramids which are separated by Na+ cations. This compound is structurally related to Na5WO4N which crystallizes in space group Cmc21
Preparation and Crystal Structures of the Isotypic Compounds CdXO4 · 2 HgO (X = S, Se)
Authors: Weil Matthias
Published: August 2018

Colourless single crystals of the compounds CdXO4 · 2 HgO (X = S, Se) were obtained under hydrothermal conditions (250 °C, 5 d), starting from stoichiometric amounts of HgO, CdSO4 ·7H2O and CdSeO4 ·2H2O, respectively. The crystal structures were determined from X-ray diffraction data sets. The CdXO4 · 2HgO compounds crystallise isotypically with two formula units in space group P1̅ (# 2) [CdSO4 · 2HgO (CdSeO4 · 2HgO): a = 6.793(2) (6.9097(5)) Å , b = 7.205(2) (7.1786(6)) Å , c=7.359(2) (7.4556(6)) Å ,α =73.224(6) (74.586(2))°, β =66.505(6) (68.229(1))°, γ =63.054(5) (63.886(1))°, 1670 (1786) structure factors, 92 parameters, R[F2 > 2σ(F2)] = 0.0379 (0.0244)] and are made up from zig-zag [O-Hg-O]∞ chains with very short bonds of d̅(Hg-O) 2.025 Å , distorted [CdO6] octahedra (d̅(Cd-O)= 2.297 Å ), and XO4 tetrahedra (d̅(S-O)= 1.458 Å , d̅(Se-O)= 1.633 Å ) as the main building blocks. The CdXO4 ·2HgO compounds reveal no structural relationship with the corresponding HgXO4 ·2HgO phases
Absolute Konfiguration von (+)-1,2,3,4,6,7,8,8a-Octahydro-6-isochinolon- 8a-carbonsäuremethylester und die Stereochemie einer Kupfer-katalysierten asymmetrischen Michael-Reaktion / Absolute Configuration of Methyl (+)-1,2,3,4,6,7,8,8a-Octahydro-6-isoquinolone-8a-carboxylate and Stereochemistry of a Copper-Catalyzed Asymmetric Michael Reaction
Authors: Christoffers Jens , Frey Wolfgang , Scharl Heiko , Baro Angelika
Published: August 2018

Enantiopure Boc-protected piperidine derivative (+)-5c, with a quaternary stereocenter, was obtained by copper-catalyzed, L-valine diethylamide-mediated Michael reaction. For determination of the absolute configuration, 5c was derivatized by cyclization with pyrrolidine/AcOH to give compound 6 with bicyclo[4.4.0]-constitution, deprotection of the amino function with TFA and subsequent reaction with 2-iodobenzoic acid to yield the crystalline bicyclic amide 7. X-ray crystallographic analysis confirmed the constitution of compounds 5c and 6 and established the (R) configuration of 7. Thus, starting Michael addition product (+)-5c has to be (S) configured, because an epimerization at the quaternary stereocenter is excluded. This result is in accordance with our working model of the Cu-catalyzed, auxiliary-assisted Michael reaction.
Reactions of 3-Chloropropeniminium Salts with Aminopyridines. Synthesis of N-Pyridylpyridinium and Pyrido[1,2-a]pyrimidinium Salts
Authors: Girreser Ulrich , Heber Dieter , Rostaie-Gerylow Mojgan , Schütt Martin
Published: August 2018

N-(Pyridyl)pyridinium salts 7 and 8 as well as 4-phenylpyrido[1,2-a]pyrimidinium salts 4 and 12 have been prepared by reactions of 3-aryl-3-chloropropeniminium salts 5 with aminopyridines (6) using glacial acetic acid as solvent. 2-Phenylpyrido[1,2-a]pyrimidinium salts 2 are formed when ethanol is used as the solvent. The condensation of 2-aminopyridine (6a) with 3-chloro-2,3- dehydromorpholino-2-carbiminium salt 13 is described. The HSAB principle of Pearson is discussed to explain the different regioselective ring closure reactions.
Cleavage of a Dibenzotetraazafulvalene to Yield a Rh(I) Carbene Complex
Authors: Hahn F. Ekkehardt , Fehren Thorsten von , Wittenbecher Lars , Fröhlich Roland
Published: August 2018

The reaction of the dibenzotetraazafulvalene C6H4(NC2H5)2C=C(NC2H5)2C6H4, 1 = 1, with [(COD)Rh(μ-Cl)2Rh(COD)] proceeds via cleavage of the C=C double bond and yields the carbene complex [(COD)RhCl(1)], 2. The X-ray structure analysis shows 2 to be a mononuclear complex with a rhodium(I) center coordinated in a slightly distorted square-planar fashion.
Iridoid and Phenylethanoid Glycosides from Phlomis nissolii and P. capitata
Authors: Kırmızıbekmez Hasan , Piacente Sonia , Pizza Cosimo , Dönmez Ali A. , Çaliș İhsan
Published: August 2018

A new iridoid glucoside, lamiidic acid was isolated from Phlomis nissolii, along with one known iridoid glucoside, lamiide and 13 phenylethanoid glycosides, verbascoside, isoverbascoside, leucosceptosides A and B, martynoside, arenarioside, forsythoside B, alyssonoside, lamiophlomiside A, samioside, integrifoliosides A and B, and hattushoside. A new iridoid glucoside, ipolamiidic acid was isolated from Phlomis capitata together with two known iridoid glucosides, lamiide and ipolamiide. The known phenylethanoid glycosides, isoverbascoside, forsythoside B, alyssonoside and hattushoside, a known lignan glycoside, liriodendrin, three flavonoid glycosides, luteolin 7-O- (6”-O-α-L-rhamnopyranosyl)-β -D-glucopyranoside, luteolin 7-O-(6”-O-β -D-apiofuranosyl)-β -Dglucopyranoside and chrysoeriol 7-O-β -D-glucopyranoside, an acyclic monoterpene, betulalbuside A, and a quinic ester derivative, chlorogenic acid were also obtained and characterized. The structures of the isolated compounds were elucidated by means of spectroscopic (HRESI-MS, 1D and 2D NMR) evidence.
Unprecedented Coordination Environment in Poly-{μ-bis(methylthienyltellane)( chlorido)(thienyl)platinum(II)}
Authors: Oilunkaniemi Raija , Laitinen Risto S. , Ahlgrén Markku
Published: August 2018

The reaction of methylthienyltellane TeMeTh (Th = thienyl, C4H3S) and [PtCl2(NCPh)2] affords in addition to the main product [PtCl2(TeMeTh)2], also small amounts of yellow crystalline [PtCl(Th)(TeMeTh)2]n that exhibits unprecedented quasi-octahedral coordination environment around platinum(II). There are four weak Pt-Te bonds of 2.898(1) and 3.419(1) Å forming an approximate squareplane the quasi-octahedral coordination being completed by a Pt-Cl bond of 2.400(2) Å and a Pt-C bond of 1.998(8) Å of a discrete thienyl ring. The TeMeTh acts as a bridging ligand. Tellurium shows a distorted tetrahedral coordination and the weak Pt-Te bonds can be rationalized in terms of sharing one tellurium electron lone-pair by two adjacent platinum centers. The closest contacts between the polymer chains involve thienyl rings.
Neue Erdalkalimetall-reiche binäre Indide: Ca2In, Sr28In11 und Sr5In3 / New Alkaline Earth Rich Binary Indides: Ca2In, Sr28In11 und Sr5In3
Authors: Wendorff Marco , Röhr Caroline
Published: August 2018

The new binary alkaline earth rich indides Ca2In (orthorhombic, space group Pnma, a =727.5(2), b = 537.1(2), c = 999.0(3) pm, Z = 4, R1 = 0.0252, Co2Si structure type) and Sr28In11 (orthorhombic, space group Imm2, a=582.6(3), b=6687.8(9), c=823.5(6) pm, Z =2, R1=0.0571, Ca28Ga11 structure type) have been synthesized from stoichiometric melts of the elements. Both crystal structures exhibit isolated In atoms coordinated by seven to ten alkaline earth atoms. In the crystal structure of Sr5In3 (tetragonal, space group I4/mcm, a = 874.4(3), c = 1642.9(8) pm, Z = 4, R1 = 0.0347, Cr5B3 structure type) isolated In atoms coexist with In2 dumbbells exhibiting short In-In contacts (284.4 pm). The electronic structures of the less elaborate compounds Ca2In and Sr5In3 are discussed in comparison with those of the closely related, nominally electron precise Zintl compounds Ca2Sn and Sr5Sn3.
Neue 3-Imidazolin-1-oxyl-Radikale mit pyridyl und chinolylhaltigen 4-(2-Aminovinyl)-Substituenten und Palladium, Platin und Ruthenium-Komplexe mit diesen 4-Amino-1-azadien-Liganden / New 3-Imidazoline-1-oxyl Radicals with Pyridyl and Quinolyl Containing 4-(2-Aminovinyl) Substituents and Palladium, Platinum and Ruthenium Complexes of these 4-Amino-1-aza-diene Ligands
Authors: Sommer Christian , Nöth Heinrich , Ponikwar Werner , Beck Wolfgang
Published: August 2018

The addition of pyridyl and quinolyl nitriles to the 4-lithium salt of 1-hydroxy-2.2.4.5.5- pentamethyl-3-imidazoline with a silyl protected OH group affords 4-aminovinyl substituted imidazoline derivatives 3, 6, 9, 12, and 15 which can be converted into the corresponding nitroxide radicals 5, 8, 11, 14 and 17. The 4-amino-1-azadiene residues of these imidazoline nitroxides form a series of chelates of palladium (22 - 26, 29 - 32) and with ruthenium half sandwich complexes (33 - 36). Coordination of the pyridine or quinoline N atom has been observed in mononuclear (19 - 21) and trinuclear (27, 28) palladium complexes and the structure of 19 was determined by X-ray diffraction.
Adducts of the Heavier Group 13 Element Halides with Aminoiminoboranes
Authors: Böck Barbara , Braun Ulrike , Habereder Tassilo , Mayer Peter , Nöth Heinrich
Published: August 2018

2,2,6,6-Tetramethylpiperidino-tert-butylimino borane, 1a, and 2,2,6,6-tetramethyl-piperidino-2,6- diisopropylphenylimino borane (1b), react with the trichlorides of Al, Ga and In or with AlBr3 to 1:1 to give the addition products tmp=B=N(ECl3)tBu (E = Ga (2a), In (2b) and tmp = B = N(EHal3)(C6H3,2,6-iPr2), (E = Al, Hal = Cl, (2c), E = Al, Hal = Br (2d)). E = Ga, Hal = Cl (2e). All these compounds have an allene type structure with short BN bonds as shown by the determination of the crystal structures of 2a, b. NMR data are in accord with this structure. No isomerization to tmp-BHal-NR-EHal2 has been observed at temperatures up to their melting points
Reduction of Carbonyl Compounds with NaBH4 under Ultrasound Irradiation and Aprotic Condition
Authors: Zeynizadeh Behzad , Yahyaei Saiedeh
Published: August 2018

A variety of carbonyl compounds are reduced to their corresponding alcohols with sodium borohydride under ultrasound irradiation and aprotic condition. Reduction reactions are performed in THF at room temperature or under reflux condition. The product alcohols were obtained in good to excellent yields. The chemoselective reduction of aldehydes over ketones was achieved successfully with this system.
Synthesis of 5-Methyl-1,2,3,4,5,6-hexahydrocyclopenta[g]carbazole-1,7- diones and Crotonyl-2-isopropyl-1-oxo-1,2,3,4-tetrahydrocarbazoles from 1-Oxo-1,2,3,4-tetrahydrocarbazoles by Friedel-Crafts Reaction
Authors: Danish Isravel A. , Prasad Karnam J. R.
Published: August 2018

The reaction of 1-oxo-1,2,3,4-tetrahydrocarbazoles (1) with crotonic acid in polyphosporic acid afforded hitherto unknown 5-methyl-1,2,3,4,5,6-hexahydrocyclopenta[g]carbazole-1,7-diones (2) and 6-crotonyl-2-isopropyl-1-oxo-1,2,3,4-tetrahydrocarbazoles (3) in a single step. A plausible mechanism for the formation of the title compounds has been proposed, and all new compounds were characterized by IR, NMR, mass spectral methods and elemental analysis.
Ethenetetracarbonitrile and Heterocyclization of Symmetrical Dithiobiurea as well as Thioureidoethylthiourea Derivatives
Authors: Hassan Alaa A. , Mourad Aboul-Fetouh E. , El-Shaieb Kamal M. , Abou-Zied Ashraf H.
Published: August 2018

N,N’-Disubstituted hydrazinecarbothioamides 6a - c and substituted thioureidoethylthioureas 12a - c react with ethenetetracarbonitrile (TCNE) in ethyl acetate or chlorobenzene to form the derivatives of pyrazole 7, 8; thiadiazole 10, 11 thiadiazepine 9, thiadiazepane 13, imidazolidine 14 and diazepine 15.
Metal Complexes of Biologically Important Ligands, CLV [1]. Some Derivatives of 4-Ethynylphenylalanine
Authors: Enzmann Armin , Beck Wolfgang
Published: August 2018

The benzoyl protected 4-ethynyl-L-phenylalanine methyl ester gives with octacarbonyldicobalt and ethylene-bis(triphenylphosphine)platinum(0) the complexes Co2(CO)6(HC≡CR) and (Ph3P)2 Pt(HC≡CR) (R = p-C6H4CH2CH(CO2Me)N(HCOPh).

The heterocumulene [Cp(Ph3P)2Ru=C=C(H)R]+BF4
− (R = p-C6H4CH2C(H)N(H)-Boc is formed from [Cp(Ph3P)2Ru]+BF4
− and N-t-Boc-4-ethynylphenylalanine methyl ester. The alkynyl bridged tetraamino acid with a tetraphenylmethane backbone C[p-C6H4C≡C-p-C6H4-CH2CH(CO2Me)NH-t- Boc]4 was synthesized from tetrakis(4-iodophenyl)methane and N-Boc-4-ethynylphenylalanine methyl ester by Sonogashira coupling.
Direct Conversion of an ortho-Allylphenol into a Chlorosulfonyl-3-methyl-1,2-benzoxathiin 2,2-Dioxide
Authors: Qaisi Ali M. , El-Abadelah Mustafa M. , Voelter Wolfgang
Published: August 2018

A one-pot synthesis of methyl 6-chlorosulfonyl-3-methyl-1,2-benzoxathiin-8-carboxylate 2,2- dioxide (9), characterized as its 6-(4-methylpiperazin-1-yl)sulfonyl derivative 10, is achieved via direct reaction of methyl 3-allylsalicylate (1) with chlorosulfonic acid at −7°C. The latter reagent converts methyl 2-methyl-2,3-dihydrobenzofuran-7-carboxylate (3) into the respective 5-chlorosulfonyl derivative 7 (identified as its 5-(4-methylpiperazin-1-yl)sulfonyl derivative 8), while contrary to literature reports, the aromatic δ -sultones 9, 10 (anticipated to be produced from 3) were not detected.
Synthesis, Crystal Structures and Properties of Three New Tetrathiomolybdates with Organic Ammonium Cations
Authors: Srinivasan Bikshandarkoil R. , Dhuri Sunder N. , Poisot Martha , Näther Christian , Bensch Wolfgang
Published: August 2018

Three new tetrathiomolybdates (pipH2)[MoS4] (1), (trenH2)[MoS4]·H2O (2) and [(prop)4N]2- [MoS4] (3) (pip = piperazine, tren = tris(2-aminoethyl)amine and prop = n-propyl) were synthesized and characterized by elemental analysis, infrared spectroscopy, single crystal X-ray crystallography, and thermoanalysis. All compounds were prepared by the base promoted cation exchange method, i.e. by the reaction of the ammonium salt of [MoS4]2− with the corresponding organic amine or organic ammonium hydroxide. In the compounds 1 and 2 the organic amines pip and tren are diprotonated and they are linked to the tetrahedral [MoS4]2− dianions through weak hydrogen bonding interactions. The strength and number of these hydrogen bonds affect the Mo-S bond lengths and a relatively long Mo-S bond of 2.2114(8) Å is observed in 1 while the longest Mo-S bond in 2 is 2.1951(5) Å . In compound 3 no S···H-N interactions are possible and the Mo-S bond lengths scatter in a more narrow range compared to those in compounds 1 and 2. The thermal behavior was investigated using differential thermal analysis and thermogravimetry. On heating compound 1 decomposes in two closely related steps while 2 loses first the crystal water followed by the decomposition of the tetrathiomolybdate. The final products are amorphous molybdenum sulfides. The decomposition of compound 3 yields a very porous material with sponge-like morphology.
Secondary Interactions in Gold(I) Complexes with Thione Ligands, 3. Three Ionic Dimesylamides [1, 2]
Authors: Friedrichsa Friedrichsa , Jones Peter G.
Published: August 2018

Three structures of the form bis(thione)gold(I) di(methanesulfonyl)amide [thione = imidazolidine- 2-thione, 1; 1-methyl-imidazolidine-2-thione, 2; thiazolidine-2-thione, 3] were determined; all crystallize with one formula unit in the asymmetric unit. Each N-H hydrogen bond donor forms one classical two-centre hydrogen bond with an anion acceptor. Compound 1 thereby forms a complex layer structure with a layer thickness of 10.17 Å ; the packing may be analysed in terms of thinner subunit layers consisting of interlinked, hydrogen-bonded chains and rings. Compound 2 forms a chain structure consisting of a series of “hairpin bends”, a common feature in the gold complexes of 1-alkyl-imidazolidine-2-thiones. Compound 3 forms a corrugated ribbon structure in which the central region consists of parallel S-Au-S axes linked by aurophilic interactions; the anions exercise a “clamping” function by forming hydrogen bonds at the periphery of the ribbons. Further short contacts can be classed as weak hydrogen bonds C-H ··· X, with X = N, O, S or Au.
Synthesis and Structure of the Helicate (M)-(–)-[Pt2 {(R,R)-tetraphos}2](CF3SO3)4 · 4.5 H2O
Authors: Kitto Heather J. , Rae A. David , Willis Anthony C. , Zank Johann , Wild S. Bruce
Published: August 2018

The complex (M)-(-)-[Pt2{(R,R)-tetraphos}2](CF3SO3)4 · 4.5 H2O, where tetraphos = 1,1,4,7, 10,10-hexaphenyl-1,4,7,10-tetraphosphadecane, has been isolated and structurally characterized. The compound crystallizes in the space group C2 with two crystallographically different, but very similar, cations in the structure, each of which contains a 2-fold axis coincident with the crystallographic 2-fold axis. Each independent cation of the salt consists of a double-stranded, diplatinum(II) helicate that completes a ca. one-eighth turn of a double α-helix in the M direction, as evidenced by the angle between the two, non-orthogonal PtP4 square planes in each of the independent molecules. A feature of the structures is the 10-membered ring containing the two platinum atoms and the four chiral phosphorus stereocentres of R configuration; this ring has a distorted twist-boat-chair-boat conformation of λ helicity, which is responsible for the M twist of the helicate.
Trioxorhenium(VII) Complexes with Imidazolin-2-iminato Ligands
Authors: Tamm Matthias , Beer Stephan , Herdtweck Eberhardt
Published: August 2018

The Staudinger reaction of the N-heterocyclic carbenes 1,3-di-tert-butylimidazolin-2-ylidene (1a), 1,3-dimesitylimidazolin-2-ylidene (1b) and 1,3-diisopropyl-4,5-dimethylimidazolin-2- ylidene (1c) with trimethylsilyl azide in boiling toluene furnishes the corresponding 2- (trimethylsilylimino)imidazolines 2a - c. Treatment of Re2O7 with a twofold excess of these N-silylated imines results in the formation of the imidazolin-2-iminato trioxorhenium(VII) complexes 3a - c and hexamethyldisiloxane, Me3SiOSiMe3. The molecular structures of 2a, 3a and 3b are reported. In addition, the X-ray crystal structure determination of complex 3c · H2O is presented, which has formed by hydrolysis and cleavage of the metal-nitrogen bond in 3c. 3c · H2O consists of 2-aminoimidazolium cations and tetraoxorhenate(VII) anions, which are linked by N-H-O hydrogen bonds.
Pd(II) Complexes of N-Allyl Substituted N-Heterocyclic Carbenes
Authors: Hahn F. Ekkehardt , Heidrich Beate , Lügger Thomas , Pape Tania
Published: August 2018

The unsymmetrically substituted imidazolium salt 1-ethyl-3-allyl-imidazolium bromide 1 was synthesized by treatment of imidazole with one equivalent each of n-butyl lithium and ethyl bromide followed by treatment with one equivalent of allyl bromide. The symmetrically substituted derivatives 1,3-diallyl-imidazolium bromide 2 and 1,3-bis(3-methyl-2-butenyl)-imidazolium bromide 3 were obtained from imidazole and two equivalents of allyl bromide or 4-bromo-2-methyl-2-butenyl bromide, respectively, in the presence of sodium hydrogencarbonate as a base. The imidazolium bromides 1- 3 react with Pd(OAc)2 to afford the palladium(II) dicarbene complexes trans-[PdBr2(L)2] (L = 1- ethyl-3-allyl-imidazolin-2-ylidene, 4; L = 1,3-diallyl-imidazolin-2-ylidene, 5; L = 1,3-di(3-methyl-2- butenyl)imidazolin-2-ylidene, 6) by in situ deprotonation of the imidazolium salts. The X-ray structure analyses of 4- 6 show all three complexes to be mononuclear with palladium(II) coordinated in a square-planar fashion by two carbene and two bromo ligands.
Synthesis of Dimeric Acridine Derived Nucleic Acid Intercalators
Authors: Csuk René , Brezesinski Thorsten , Göthe Gunnar , Raschke Christian , Reißmann Stefan
Published: August 2018

A series of antiviral compounds consisting of an intercalating acridine derived part, a spacer region and a reactive EDTA-derived conjugate was synthesized in an easy sequence. Suitably monoprotected 1,ω-alkyldiamines gave upon reaction with 6,9-dichloro-2-methoxyacridine (1) followed by deprotection and reaction with EDTA dianhydride the target molecules. In the presence of ascorbate a reduction of the phage-titer of the MS2 phages by > 8 logarithmic decades was achieved.
Magnetic Properties of SmRhIn
Authors: Lukachuk Mar’yana , Hoffmann Rolf-Dieter , Pöttgen Rainer
Published: August 2018

The indide SmRhIn (ZrNiAl type, P6̅2̅m, a = 750.93(8), c = 397.52(4) pm) was synthesized from the elements by arc-melting. SmRhIn orders antiferromagnetically at 8.0(5) K. The non-linearity of the temperature dependence of the inverse susceptibility points to a large van Vleck term for the samarium atoms. Magnetization measurements indicate a metamagnetic transition at a flux density of 3 T.
Synthesis And Crystal Structures Of The Polygermanide Ammoniates K4Ge9 · 9 NH3, Rb4Ge9 · 5 NH3 And Cs6Ge18 · 4 NH3
Authors: Suchentrunk Christof , Daniels Jörg , Somer Mehmet , Carrillo-Cabrera Wilder , Korber Nikolaus
Published: August 2018

The new compounds K4Ge9 ·9 NH3 and Rb4Ge9 ·5 NH3 were prepared by the extraction of K4Ge9 and Rb4Ge9 with liquid ammonia and characterized by low temperature X-ray structure analysis. They both contain monocapped square antiprismatic Ge9
4− anions. Cs6Ge18 ·4 NH3 was prepared by the extraction of K2Cs2Ge9 with liquid ammonia in the presence of [(Bu)3MeN](Br2I) as an oxidizing agent, and contains a [Ge9-Ge9]6− dimer in which two Ge9
4− anions are linked by a single Ge-Ge bond
Zur Strukturchemie von 2-Methylenimidazolinen [1]
Authors: Kuhn Norbert , Abu-Rayyan Ahmed , Al-Sheikh Ahmed , Eichele Klaus , Maichle-Mößmer Cäcilia , Steimann Manfred , Sweidan
Published: August 2018

The 2-methylenimidazolines ImC(CN)2 (6a - c, Im = 1,3-dialkyl-4,5-dimethylimidazol-2-ylidene) are prepared by the reaction of the imidazolium salts [ImBr]Br (5) and malodinitrile while ImC{C(O)Ph}2 (7) is obtained from ImCH2 (2) and benzoic fluoride. Both the structural data of 6b, 6c, and 7 and the 13C NMR data demonstrate the influence of steric and electronic effects on the charge separation and the nonplanar arrangement of the substituents attached at the carbon atoms of the central olefinic bond
Tin(II)chloride Mediated Addition Reaction of Bromonitromethane to Aldehydes
Authors: Mahasneh Ali S.
Published: August 2018

Bromonitromethane adds to aliphatic aldehydes in the presence of tin(II) chloride to yield β -nitro alcohols via a Reformatsky-type reaction in high yields, while aromatic aldehydes give low yields. The products were characterized by IR, NMR, and mass spectroscopy and by elemental analysis
Darstellung und Kristallstruktur von Strontiumozonid-Ammoniakat, Sr(O3)2 · 9 NH3 / Synthesis and Crystal Structure of Strontium Ozonide Ammoniate, Sr(O3)2 · 9 NH3
Authors: Klein Wilhelm , Jansen Martin
Published: August 2018

Strontium ozonide has been synthesised, starting from caesium ozonide, via cation exchange in liquid ammonia. From these solutions, if kept at −78 °C for 14 days, an ammoniate, Sr(O3)2 · 9 NH3, crystallises. The coarse, ruby red crystals decompose above the boiling temperature of ammonia and are extremely sensitive to moisture. According to a single crystal structure determination (P4/nmm; a = 7.597(1), c = 13.496(2) Å , Z = 2; R1 = 7.50%; 254 independent reflections) Sr(O3)2 · 9 NH3 consists of ozonide anions and strontium cations. The complex cations form an approximately cubic close packing, where the octahedral and half of the tetrahedral interstices are occupied by ozonide anions. The anions are orientationally disordered
NaBH4/NaHSO4·H2O a Heterogeneous Acidic System for a Mild and Convenient Reduction of Carbonyl Compounds under Protic Condition
Authors: Zeynizadeh Behzad , Behyar Tarifeh
Published: August 2018

NaBH4 in the presence of sodium bisulfate (NaHSO4·H2O), a weakly acidic reagent, efficiently reduces a variety of carbonyl compounds such as aldehydes, ketones, α,β -unsaturated aldehydes and ketones, α-diketones and acyloins to their corresponding alcohols in acetonitrile under heterogeneous condition. Reduction reactions were accomplished at room temperature or under reflux condition
Deca(4-methylbenzyl)ferrocen und -stannocen / Deca(4-methylbenzyl)ferrocene and -stannocene
Authors: Schumann Herbert , Sühring Klaudia , Weimann Roman , Hummert Markus
Published: August 2018

Cyclopentadiene reacts with five equivalents of 4-methylbenzylalcohol (1:5,6 mole ratio) and sodium yielding penta(4-methylbenzyl)cyclopenta-2,4-diene (1), which upon treatment with butyl lithium affords the lithium salt [(4-MeC6H4CH2)5C5]Li (2). The reactions of 2 with FeCl2 and SnCl2 result in the formation of deca(4-methylbenzyl)ferrocene (3) and deca(4-methylbenzyl)stannocene (4), respectively. The 1H and 13C NMR, IR and mass spectra of the new compounds as well as the single crystal X-ray structure analysis of 1 are reported and discussed.
One New Prenylated Furanone and Other non Polar Constituents from Mutisia friesiana
Authors: Viturro Carmen I. , de la Fuente Juana R. , Maier Marta S.
Published: August 2018

In addition to the known furanones 1 and 2, the aerial parts of the shrub Mutisia friesiana afforded a new prenylated furanone, Mutisifuranone A (3), together with the known triterpenoids oleanic (4) and ursolic (5) acids and some sesquiterpenoids and n-alkanes. Their structures were elucidated by spectroscopic methods.
Structural Data and Vibrational Spectra of the Copper(II) Complex of L-Selenomethionine
Authors: Baran Enrique J.
Published: August 2018

A Cu(II) complex of the amino acid L-selenomethionine of stoichiometry Cu(L-SeMet)2, has been prepared and characterized. Crystallographic data were obtained by means of X-ray powder diffractometry and showed that the compound is isostructural with the related complex of L-methionine, Cu(L-Met)2. The structural analogy is also supported by the analysis of the IR and Raman spectra of the complex, which are briefly discussed in comparison with those of free L-selenomethionine.
1,3-Dimethylbarbiturat-Salze organischer Kationen / 1,3-Dimethylbarbiturate Salts of Organic Cations
Authors: Kuhn Norbert , Maichle-Mößmer Cäcilia , Niquet Elke , Steimann Manfred , Sweidan Kamal
Published: August 2018

The barbiturate salts 2-amino-1,3-dimethylimidazolium N,N’-dimethylbarbiturate (8) and 1,3- diisopropyl-4,5-dimethylimidazolium N,N’-dimethylbarbiturate (10) are obtained from N,N’- dimethylbarbituric acid (6) and 2-imino-1,3-dimethylimidazoline (7) or 2,3-dihydro-1,3-diisopropyl- 4,5-dimethylimidazol-2-ylidene (9) in good yields. Their crystal structures reveal the presence of strong interionic N-H-O (8) and C-H-O (10) hydrogen bonds to give dimeric (8) and monomeric (10) ion pairs. These pairs are linked by weak C-H-O hydrogen contacts to give three-dimensional networks.
Oxotellurate(IV) der Lanthanide: II. Die isotype Reihe M2Te5O13 (M = Dy – Lu) / Oxotellurates(IV) of Lanthanides: II. The Isotypic Series M2Te5O13 (M = Dy – Lu)
Authors: Meier Steffen F. , Schleid Thomas
Published: August 2018

For the shortly discovered formula type M2Te5O13 (triclinic, P1̄), the establishment of an isostructural series in the last third of the lanthanide family (M = Dy - Lu) was possible. The excessive formula unit TeO2 additional to the well-known composition M2Te4O11 (monoclinic, C2/c) leads to the slicing of the [M2O10]14− layers which are typical for the tellurium-oxide poorer compounds. By coupling together the bicapped trigonal prismatic (M1, CN = 8) and the pentagonal bipyramidal (M2, CN = 7) lanthanide-oxygen polyhedra via edges, [M4O20]28− bands are formed stretching along the a axis and piling up to a primitive rod-packing. The linkage of these bands occurs parallel to the (010) plane via Te3 as well as via Te4 parallel to (100). Besides the usual 3+1 coordination, two of the five crystallographically independent tellurium sites are coordinated regularly fourfold (d(Te−O) ≈ 186−213 pm) and even 3+2-fold by oxygen atoms. The tellurium-oxygen polyhedra form corrugated layers running parallel to (101) which follow so close to each other that the tellurium-oxygen partial structure appears to be almost three-dimensional at a passing glance. As in M2Te4O11-type representatives, the non-bonding electron pair (lone pair) of each Te4+ cation shows stereochemical activity which always appears to flock together in large tellurium neighboured positions.
High-Pressure Synthesis and Crystal Structure of the New Orthorhombic Polymorph β-HgB4O7
Authors: Emme Holger , Weil Matthias , Huppertz Hubert
Published: August 2018

The new orthorhombic polymorph β-HgB4O7 has been synthesized under high-pressure and hightemperature conditions in a Walker-type multianvil apparatus at 7.5 GPa and 600 °C. β-HgB4O7 is isotypic to the known ambient pressure phases MB4O7 (M = Sr, Pb, Eu) and the high-pressure phase β-CaB4O7 crystallizing with two formula units in the space group Pmn21 with lattice parameters a = 1065.6(2), b = 438.10(9), and c = 418.72(8) pm. The relation of the crystal structure of the high-pressure phase β-HgB4O7 to the normal pressure phase α-HgB4O7 as well as the relation to the isotypic phases MB4O7 (M = Sr, Pb, Eu) and β-CaB4O7 are discussed.
A Convenient Synthesis of Novel 20-, 23-, and 26-Membered Macrocyclic Oxathiadibenzo- and Oxathiadinaphthalenocrown Ethers, Part 1
Authors: Ashram Muhammad
Published: August 2018

A series of novel oxathiadibenzo- and oxathiadinaphthalenocrown ethers 1 - 18 have been successfully synthesized in good yield and in a simple way. They were characterized by NMR, mass spectroscopy and elemental analysis.
Compounds Ln5(Ag, Ga)19 – x (Ln = Gd, Tb) – Defective Partially Ordered Representatives of the Rb5Hg19 Structure Type
Authors: Gumeniuk Roman V. , Akselrud Lev G. , Kuz’ma Yurij B.
Published: August 2018

New compounds Ln5(Ag, Ga)19−x (Ln = Gd, Tb) have been found to crystallise with the Rb5Hg19 structure type (space group I4/m). The crystal structures were refined for Gd5Ag1.8Ga15 and Tb5Ag2Ga15.6 from X-ray powder data: a = 9.4635(1), c = 9.8638(2) Å , RI = 0.093 and a = 9.4313(1), c = 9.8491(2) Å , RI = 0.085, respectively. Some positions in the crystal structures of new the compounds are occupied partially.
Syntheses of New Pyridoxazines, Benzoxa(thia)azines, and Benzoxa(thia)azepines via Cyclocondensation and Elimination Reactions between Donors and Acceptors
Authors: Aly Ashraf A. , Hassan Alaa A. , El-Shaieb Kamal M. , Shaker Rafaat M.
Published: August 2018

Reaction of 3-amino-2-hydroxypyridine and 2-amino(thio)phenols with various selected π-acceptors are herein reported. Different modes of cyclization via elimination and/or condensation reactions were observed during the reaction of the donors with 3,4,5,6-tetrachloro-1,2-benzoquinone (CHLo), 2,3,5,6-tetrachloro-1,4-benzoquinone (CHL-p), 2,3-dicyano-1,4-naphthoquinone (DCNQ) and 2- dicyanomethyleneindane-1,3-dione (CNIND). A series of pyridoxazines, benzoxa(thia)azines, benzoxa( thia)azepines has been synthesized in good yields.
Synthesis and Structure of Pyrrolidinobromodiboranes(4)
Authors: Nie Yong , Pritzkow Hans , Siebert Walter
Published: August 2018

The reaction of tetrapyrrolidinodiborane(4) (1) with BBr3 in a 1:1 molar ratio yields a mixture of 1,2-dibromo-1,2- dipyrrolidinodiborane(4) (2) and bromotripyrrolidino- diborane( 4) (3), while a 1:2 molar ratio leads in Et2O to compound 2 as the main product along with a small amount of [(C4H8N)2B2Br3(OEt)] (4). The new compounds have been characterized by NMR and MS data, as well as by X-ray structure analyses of 2 and 4, of which the former exhibits an interesting polymorphism phenomenon.
Furanoeremophilanes from Roldana ehrenbergiana
Authors: Pérez-Castorena Ana-L. , Arciniegas Amira , Hernández Ma. Lourdes , de la Rosa Isai , Contreras José L. , de Vivar Alfonso Romo
Published: August 2018

Two new furanoeremophilanes, roldehrenbergin A and roldehrenbergin B, and several known compounds were isolated from Roldana ehrenbergiana. Structural determination of the new compounds was achieved by spectroscopic analyses and chemical evidence.
Effect of Preferential Solvation on the Kinetics and Thermodynamics of Oxidation of Anilines by Nicotinium Dichromate
Authors: Bhuvaneshwari Durvas S. , Elango Kuppanagounder P.
Published: August 2018

The nicotinium dichromate (NDC) oxidation of anilines, in varying mole fractions of benzene/2- methylpropan-2-ol mixtures, in the presence of p-toluenesulfonic acid (TsOH) is first order in NDC and TsOH and zero order with respect to anilines in the concentration range investigated. The NDC oxidation of 15 meta- and para-substituted anilines complies with the isokinetic relationship but not to any of the linear free energy relationships. The activation free energy data failed to correlate with macroscopic solvent parameters such as εr and ENT. Correlation of ΔG# with Kamlet-Taft solvatochromic parameters (α, β , π*) suggests that the specific solute-solvent-solvent interactions play a major role in governing the reactivity.
Synthese furanoider Zuckeraminos¨auren ausgehend von fermentativ gewonnener 2-Oxo-D-gluconsäure / Synthesis of Furanoid Sugar Amino Acids Starting from Fermentatively Produced 2-Oxo-D-gluconic Acid
Authors: Schmidt Stephan , Wilde Horst , Hunger Jens , Sicker Dieter
Published: August 2018

2-Oxo-D-gluconic acid obtained by fermentation of D-glucose was used as starting material for syntheses of amino acids. We trapped the carbohydrate in its furanoid configuration and synthesized an α- and an ω-amino acid. After deprotection of the hydroxyl groups the latter did not isomerize to the substituted piperidine (aza-sugar) as expected, but remained in the furanose form. The starting structure 2 was proven by crystal structure analysis. The conformational identification of the other substances was done by NMR measurements following known rules for furanoses.
Synthesis of Unsymmetrical Bis(imidoyl)dichlorides of Oxalic Acid
Authors: Helmholz Falko , Schroeder Rita , Langer Peter
Published: August 2018

Unsymmetrical oxalic acid-bis(imidoyl)dichlorides were prepared from ethyl 2-chloro-2-oxoacetate in three steps.
Supercritical CO2 Extraction of Essential Oil from Clove Bud: Effect of Operation Conditions on the Selective Isolation of Eugenol and Eugenyl Acetate
Authors: Yazdani Farshad , Mafi Morteza , Farhadi Fathollah , Tabar-Heidar Kourosh , Aghapoor Kioumars , Mohsenzadeh Farshid , Darabi Hossein Reza
Published: August 2018

The supercritical fluid extraction (SFE) of clove bud essential oil was studied using CO2 as solvent. The effect of operation conditions was analyzed in a series of experiments at temperatures between 325 and 416 K and pressures between 110 and 190 bar. The collected extracts were analyzed and the relative composition of the essential oil was determined. The optimum condition was found in a temperature of 353 K and at a pressure of 190 bar, minimizing the number of extracts to two compounds (eugenol and eugenyl acetate). The extract obtained from clove bud by using supercritical fluid extraction was compared with the essential oil obtained by steam distillation and microwave-assisted extraction by considering both quantity and quality of the product. The oil yield was higher in steam distillation and microwave oven extraction. In contrast, oil extracted by using SFE contained higher amount of eugenol and eugenyl acetate.
Studies on the Constituents of Commiphora mukul
Authors: Sultana Nighat , Atta-ur-Rahman  , Jahan Sarwat
Published: August 2018

Studies on ommiphora mukul (Hook, ex stock) Engl. have led to the isolation of a new lignan (+)-commiphorin (1), a new fatty acid ester, (+)-commiphotetrol (2) along with (-)- hydroxyisohopane (3) [1], which is the first report of this compound from Commiphora mukul of Pakistan origin, Z and E-guggulsterones, cholesterol and guggulsterol-II (4). Of these complete 1H and 13C NMR data of guggulsterol-II (4) is assigned for the first time [2]. The structures of the compounds were elucidated with the help of extensive spectroscopic studies [3, 4]. Compound 1 have shown antibacterial activity against a number of bacteria. Amoxicillin (H2O)3, Ampicilin and Cefuroxime were used as positive control (Table 2).
Cyclisierung von N′,N′-disubstituierten Anthranilsäurehydraziden mit 1,1′-Oxalyldiimidazol zu 4-Amino-2,3,4,5-tetrahydro-1H-1,4-benzodiaz- epin-2,3,5-trionen / Cyclization of N’,N’-Disubstituted Anthranilic Hydrazides with 1,1’-Oxalyldiimidazole to 4-Amino-2,3,4,5-tetrahydro-1H-1,4-benzodiazepin-2,3,5-triones
Authors: Geffken Detlef , Köllner Maria Anna
Published: August 2018

N’,N’-Disubstituted (2-phenylamino)-, (2-methylamino)- and (2-benzylamino)benzohydrazides (1) are cyclized by in situ prepared 1,1’-oxalyldiimidazole to give 3-amino-2,3,4,5-tetrahydro-1H- 1,4-benzodiazepine-2,3,5-triones 2 as the major product. Depending on the substituents of 1 competitive formation of quinazoline-2,4-diones 3 and 1,3,4-oxadiazoline-2-one 4 is observed. The formation of heterocycles 2, 3, 4 is rationalized via a common primary intermediate 1A.
Three New Steroidal Saponins from Smilax officinalis
Authors: da Silva Bernadete P. , Parente José P.
Published: August 2018

Three new steroidal saponins were isolated from the roots of Smilax officinalis Kunth. Their structures were established as (3β,5β,22α,25S)-26-(β-D-glucopyranosyloxy)-22-hydroxyfurostan- 3-yl O-α-L-arabinopyranosyl-(1→6)-O-[β-D-glucopyranosyl-(1→4)]-β-D-glucopyranoside, (3β,5α,22α,25S)-26-(β-D-glucopyranosyloxy)-22-hydroxyfurostan-3-yl O-α-L-arabinopyranosyl-( 1→6)-O-[β-D-glucopyranosyl-(1→4)]-β-D-glucopyranoside and (3β,5α,6β,22α,25S)-26-(β- D-glucopyranosyloxy)-6,22-dihydroxyfurostan-3-yl O-α-L-arabinopyranosyl-(1→6)-O-[β-D-glucopyranosyl-( 1→4)]-β-D-glucopyranoside. Their structure elucidations were performed using detailed analyses of 1H and 13C NMR spectra including 2D NMR spectroscopic techniques (DEPT, COSY, HSQC, HMBC and HMQC) and chemical conversions.
Electron Release and Proton Acceptance Reactions of (dpp-BIAN)Mg(THF)3
Authors: Fedushkin Igor L. , Chudakova Valentina A. , Hummert Markus , Schumann Herbert
Published: August 2018

(dpp-BIAN)Mg(THF)3 (1) (dpp-BIAN = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) and (PhCOO)2 react with splitting of the peroxide bridge and formation of the dimeric magnesium benzoate [(dpp-BIAN)MgOCOPh(THF)]2 (2). The reaction of 1 with PhCOOH yields the dimeric magnesium benzoate [(dpp-BIAN)(H)MgOCOPh(THF)]2 (3), whereas 1 and furanyl-2-carboxylic acid react with liberation of hydrogen and formation of (dpp-BIAN)Mg[OCO(2-C4H3O)]2 Mg(dpp-BIAN)(THF) (4). Compounds 2, 3, and 4 have been characterized by elemental analysis, IR spectroscopy, and X-ray structure analysis, compound 3 also by 1H NMR spectroscopy. The eightmembered metallacycles of the centrosymmetric dimers 2 and 3 are almost completely planar. The two magnesium atoms in 4 show different coordination spheres; one is surrounded by its ligands in a trigonal bipyramidal manner, the other one in a tetrahedral fashion. The Mg···Mg separations in 2, 3 and 4 are 4.236, 4.296, and 4.030 Å, respectively
Protodeborylation of Triorganoboranes
Authors: Wrackmeyer Bernd , Khan Ezzat , Kempe Rhett
Published: August 2018

Protodeborylation of triorganoboranes, usually carried out under mild reaction conditions using an excess of acetic acid, affords 1,5-dialkyl-3,7-dimethyl-4,8,9-trioxa-2,6-dioxonia-1,5-diboratabicyclo [3.3.1]nona-2,6-dienes OB(R)OC(Me)OB(R)OC(Me)O [1 (R = Et), 2 (R = cyclooctyl)]. Acetoxy(dialkyl) boranes and di(acetoxy)alkylboranes were not formed in an appreciable amount. Compounds 1 and 2 were characterized by NMR spectroscopy (1H, 11B, 13C NMR) in solution, the molecular structure of 2 was determined by X-ray analysis. The gas-phase geometry of 1 was optimized by calculations [B3LYP/6-311+G(d, p) level of theory], and its NMR parameters were also calculated at the same level of theory.
Synthesis, Crystal Structure and Antitumor Study of a Zinc Complex of the 2-Benzoylpyridine Thiosemicarbazone Ligand
Authors: Li Ming Xue , Zhou Jing , Chen Chun Ling , Wang Jing Ping
Published: August 2018

A zinc complex of the 2-benzoylpyridine thiosemicarbazone (Hbpt) ligand, Zn(bpt)2 · DMF, has been synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The molecular structure has a Zn2+ cation bonded to two perpendicular bpt ligands in a distorted octahedral geometry through two sulfur and four nitrogen atoms. The crystal contains a disordered DMF solvate molecule. Adjacent molecules are interconnected by means of hydrogen bonding generating a 1-D chain structure. The cytotoxic activity measurement indicates that the complex exhibits higher antitumor activity against lung cancer A549 cell lines than the free ligand.