bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereospecific Association of C-20 Epimers of 3β-Hydroxy-16-oxo-24-nor-17-azachol-5-eno-23-nitryle
Authors: Plesnar Zofia , Malanowski Stanisław , Lotowski Zenon , Morzycki Jacek W. , Frelek Jadwiga , Wójcik Jacek
Published: August 2018

The cryoscopic measurements show that title compounds are strongly associated in CHCl3 solutions. The association of the 20 R epimer is distinctly less pronounced than that of the 20 S epipmer. Self-association of the 20 S epimer leads to the formation of very large com­plexes. The 20 R epimer forms associates via water molecules. The dissimilarity may be ex­plained in terms of different accessibility of the lactam carbonyl groups in the two epimers for the association. It is proposed that the association process is controlled by the configura­tion at the carbon atom C(20) and conformation around the C(20)-C(22) bond. Populations of side chain conformations of both epimers were determined by means of proton nuclear magnetic resonance. It was found for the 20 R epimer that the t and the -g rotamers are almost equally populated, and the rotamer +g is excluded. For the 20 S epimer the +g rotamer predominates over the t one, and the -g rotamer is excluded. The NMR data are fully consistent with the results of the molecular modelling studies.
1.3-Dithienium-and 1.3-Dithiolenium Salts, VI ,13C NMR Spectroscopic Investigations on 2-Substituted 1,3-Dithian-2-ylium Cations. Unusual γ-Effects
Authors: Kalinowski Hans-Otto , Stahl Ingfried
Published: August 2018

The 13C NMR chemical shifts of 19 2-substituted 1,3-dithian-2-ylium-tetrafluorborates 1a-1s are discussed in comparison to known analogous 1,3-dithianes and 2-lithio-1,3-dithianes. The unusual γ-effects (up to 9 ppm), which can also observed in other six-membered ring systems, are explained by the electric field effect (σ-polarisation effect). The electron density distribution can be estimated qualitatively by comparison with the 1,3-dioxan-2-ylium-and cyclohexylcations.
Notizen: Facile Preparation and Crystal Structure of [Bis(diphenylphosphino)amine]digold Dichloride
Authors: Lange Peter , Schier Annette , Schmidbaur Hubert
Published: August 2018

Treatment of bis(diphenylphosphino)amine (dppa) with (dimethylsulfide)gold(I) chloride in the molar ratio 1:2 leads to the dinuclear complex (dppa)Au2Cl2 in 95% yield. The compound was crystallized from diethyl ether/dimethylformamide as the 1:1 solvate with dmf, the crystal structure of which has been determined. The complex features an intramolecular Au--Au contact [3.121(1) Å] and an intermolecular hydrogen bond NH--O=C.
Chemie polyfunktioneller Moleküle, 127 PPh2-Eliminierung aus dem PP-verknüpften Phosphazen Ph2P-N=PPh2-PPh2=N-PPh2 mit [C5H5Fe(CO)(μ-CO)]2; Kristallstrukturanalyse des Phosphazen-Derivats /Chemistry of Polyfunctional Molecules, 127 PPh2 Elimination from the PP Connected Phosphazene Ph2P-N=PPh2-PPh2=N-PPh2, with [C5H5Fe(CO)(μ-CO)]2; Crystal Structure of the Phosphazene Derivative
Authors: Ellermann Jochen , Schütz Martin , Heinemann Frank W. , Moll Matthias , Bauer Walter
Published: August 2018

The reaction of Ph2P-N=PPh2-PPh2=N-PPh2 (Ph = C6H5, 2) with [CpFe(CO)(μ-CO)]2 (Cp = C5H5, 3) yields under elimination of a PPh2-group from 2 and cleavage of the Fe-Fe bond in 3 the monocyclic ferraphosphazene complex Cp(OC)

(4) and Ph2P-PPh2 (5). In a side reaction the P-P bond of 2 is also cleaved in a redox process to give Cp(OC)

(7). Compound 4 has been characterized by a crystal structure determination.
Synthese und Struktur eines zweikernigen Uranylkomplexes mit acyclischem, mehrzähnigem Aminoalkohol als Chelatligand: Lösungsmittelinduzierte supramolekulare Struktur/Synthesis und Structure of a Binuclear Uranyl Complex with an Acyclic, Multidentate Amino Alcohol as Chelate Ligand: Solvent Induced Supramoleculare Structure
Authors: Plass Winfried , Fries Guido
Published: August 2018

The pentadentate Schiff base ligand N-salicylidene-2-(bis(2-hydroxyethyl)amino)ethyl-amine (H3sabhea) reacts with uranyl dinitrate hexahydrate in methanol or ethanol to yield the binuclear uranyl complex [{UO2(Hsabhea)}2]. Depending on the solvent two crystalline modi­fications can be isolated, which were studied by single-crystal X-ray diffraction; From ethanol [{UO2(Hsabhea)}2] (1) (monoclinic space group P21/c, a = 1029.2(4) pm, b = 1342.9(6) pm, c = 1153.5(5) pm, β= 109.88(3)°, Z = 2); from methanol [{UO2(Hsabhea)}2]·2/3MeOH (2) (triclinic space group P1̄, a = 1125.9(3) pm, b= 1347.4(4) pm, c= 1632.5(6) pm, α = 91.78(3)°, β= 92.17(3)°, γ = 104.96(2)°, Z = 3). Differences between 1 and 2 are associated with the hydrogen bonding scheme involving the hydroxyethyl group as the donor, but the uranyl oxo group as acceptor for 1 and the phenolate oxygen atom as acceptor for 2. The compounds have been characterized by vibrational (IR and Raman), NMR, and UV/Vis spectroscopy. The differences in the supramolecular structure of the compounds and the related differences in their physical properties are discussed.
Die Fulven-Route zum Pentaisopropylcyclopentadienid / The Fulvene Route to Pentaisopropylcyclopentadienide
Authors: Dezember Thomas , Sitzmann Helmut
Published: August 2018

Sodium tetraisopropylcyclopentadienide (2) is attacked selectively in 5-position by tosyl azide with formation of 5-diazo-1,2,3,4-tetraisopropylcyclopentadiene (1) and also by the iminium salt [Me2NC(H)OMe]+ MeOSO3- to yield 1,2,3,4-tetraisopropyl-6-dimethylamino-pentafulvene (3) with concomitant methanol elimination. In a one pot reaction 3 adds methyllithium to form a cyclopentadienide intermediate (4) which is converted in situ to 1,2,3,4- tetraisopropyl-6-methyl-pentafulvene (5) with dimethylchlorosilane. By the same procedure with 1,4-dilithiobutane instead of methyllithium two tetraisoproylfulvene moieties are linked to the bis-fulvene 8 with a -(CH2)4- backbone. 3 can be converted directly to 1,2,3,4- tetraisopropylpentafulvene (7) with diisobutylaluminum hydride. 5 again adds methyllithium to give lithium pentaisopropylcyclopentadienide (6) or can be deprotonated at the 6-methyl group with potassium hydride. The intermediate potassium salt gives 1,2,3,4-tetraisopropyl- 6-trimethylsilylmethyl-pentafulvene (9) with trimethylchlorosilane. The fulvene 7 could be η6-coordinated to the tricarbonyl chromium complex 10 with [Cr(CO)3(NCEt)3], 5 and 7 yield the molybdenum analogues 11 and 12 with [Mo(CO)3(NCEt)3].
Synthese, Struktur-und EPR-Untersuchungen an 57Fe-markiertem Tetra-n-butylammonium-bis(1,1-dicyanoethen-2,2-dithiolato)nitrosyleisen(I), (n-Bu4N)2 [57Fe(NO)(i-mnt)2] / Synthesis, Structural, and EPR Investigations on 57Fe Enriched Tetra-n-butylammonium- bis(1,1-dicyanoethene-2,2-dithiolato)nitrosyliron(I), (n-Bu4N)2[57Fe(NO)(i-mnt)2]
Authors: Möller Einar , Sieler Joachim , Kirmse Reinhard
Published: August 2018

Abstract The molecular structure and X-as well as Q-band EPR studies of tetra-n-butylammonium-bis(1,1-dicyanoethene-2,2-dithiolato)nitrosyliron(I) enriched with 57Fe are reported, (n-Bu4N)2[Fe(NO)(i-mnt)2] crystallizes triclinically, space group P1̄ with a = 9,5147(7) Å, b = 10,4841(8) Å, c = 25,840(2) Å, α= 92,510(1)°, β= 92,895(1)°, γ= 111,156(1)° , Z = 2. The g and the hyperfine coupling tensors AN and AFe derived from the EPR spectra are rhombically-symmetric: g1 = 2,043, g2 = 2,039, g3 = 2,031, A1N = 13,8·10-4 cm-1, A2N = 11,6·10-4 cm-1, A3N = 15,2·10-4cm-1, A1Fe = 11,4·10-4cm-1, A2Fe = 15,7·10-4cm-1 and A3Fe = -2,6·10-4cm-1. The spin-density distribution within the first coordination sphere is discussed.
CuX (X = Br, I) Oligomers and Polymerie Chains in Tetramethylcyclotetra- arsoxane-Bridged Networks [CunXn{cyclo-(CH3AsO)4}2] (n = 4, 6, 8)
Authors: Müller Iris M , Sheldrick William S
Published: August 2018

Open lamellar structures 2∞[Cu4I4{cyclo-(CH3AsO)4}2] (1) and 2∞[{CuX(CuX · CH3CN)2}{cyclo-(CH3AsO)4}] [X = Br (2), X =I (3)] may be prepared by self-assembly from CuX and methylcycloarsoxane (CH3AsO)n in acetonitrile solution at 100- 130 °C. Whereas 1 contains CU4I4 oligomers consisting of three fused (Cul)2 rings, 2 and 3 exhibit infinite 1∞[CuX] single chains. An acceleration in the rate of heating between 20 and 100 °C from 2 °C h-1 to 5 °C h-1 for CuBr:As = 2:1 allows the isolation of the chain structure 1∞[{(CuBr)2(CuBr · CH3CN)2{cyclo-(CH3AsO)4}] (4), as an intermediate product on the reaction pathway to 2. Compound 4 contains cage-like [Cu4Br3(AsO)4] units in which the Cu and Br atoms belong to a 1∞[Cu2Br2] double chain containing fused (CuBr)3 six-membered rings.
Notizen: Determination of Signs of Coupling Constants for (Ethene)bis- (triphenylphosphane)platinum(0)
Authors: Wrackmeyer Bernd
Published: August 2018

The signs of coupling constants [ 1J(195Pt,13C) (> 0), 2J(195Pt,1H) (< 0), ∑2J (31P,13C)trans + 2J(31P,13C)cis (> 0) and ∑3J(31P,1H )trans +3J(31P,1H)cis (< 0)] in (ethene)bis(triphenylphosphane) platinum (0) (1) were determined by selective heteronuclear double and triple resonance experiments of the type 1H{31P}, 13C{1H,31P} and two-dimensional heteronuclear shift correlations (HETCOR) of the type 13C/1H, 195Pt/1H, and 31P/1H, either by observing the heteronucleus or 1H in the more sensitive inverse mode.
Synthese thermisch stabiler N-Silylformaldehyd-hydrazone / Synthesis of Thermally Stable N-Silylformaldehyde-Hydrazones
Authors: Klingebiel Uwe , Knipping Karin , Witte-Abel Henning
Published: August 2018

In the reaction of monosilylhydrazines and aqueous form aldehyde solution the first monomeric and therm ally stable N-silylformaldehyde-hydrazones [1-3] are obtained.
Structural Study of an N(4)-Substituted Thiosemicarbazone Prepared from 1-Phenyl-1,2-propanedione-2-oxime, and of a Related Nickel(II) Complex
Authors: Bermejo Elena , Castiñeiras Alfonso , West Douglas X.
Published: August 2018

1-Phenyl-1,2-propanedione-2-oxime reacts with 3-piperidylthiosemicarbazide and 3-hexamethyleneiminylthiosemicarbazide to give the respective 1-phenyl-1,2-propanedione-1-thiosemicarbazone-2-oximes, HPopip and HPohexim. The crystal structure of HPopip shows the oxime and thiosemicarbazone moieties in a conformation single-trans respect to carbon-carbon. A six-coordinate nickel(II) complex, [Ni(Pohexim)2], has two monoanionic (through loss of a proton from the thiosemicarbazone function) oxime-thiosemicarbazone ligands coordinated in a meridonal arrangement via the oxime nitrogen, the thiosemicarbazone imine nitrogen and the thiolato sulfur atoms. The bond distances to nickel are shorter than found for other six-coordinate complexes with monoanionic tridentate thiosemicarbazone ligands.
Metallkomplexe mit biologisch wichtigen Liganden, CXXXVII [1]. Halbsandwich-Komplexe mit N, O-Chelaten und Schiff-Basen von β-Aminosäuren/ Metal Complexes of Biologically Important Ligands, CXXXVII [1]. Halfsandwich Complexes with N, O-Chelates and Schiff Bases of β-Amino Acids
Authors: Koch Daniela , Hoffmüller Winfried , Polborn Kurt , Beck Wolfgang
Published: August 2018

β-Phenylalanine forms with chloro bridged complexes the chiral N, O-chelates Cp*Ir(Cl)(NH2CH(Ph)CH2CO2) and (p-cymene)Ru(Cl)(NH2CHPhCH2CO2) as mixture of two diastereoisomers. Similarly the palladium(III) and platinum(II) complexes (Et3P)(Cl)M(NH2CH(Ph)CH2CO2) (M = Pd, Pt) were obtained. Schiff base complexes (arene)(Cl)M(O2CC(R)=N-CH(R)CH(R)CH2CO2CH3) (arene = Cp*, p-cymene; M = Ir, Ru) were synthesized from the chloro-bridged compounds, 2-oxocarboxylates and β-alanine or β-phenylalanine methylester. The Cp*Ir complex with a tridendate dianionic Schiff base generated from pyruvate and β-phenylalaninate is obtained as a single isomer. Cp*Ir(Cl) forms a complex with an N, O-bidentate Schiff base ligand from glycinate and acetylacetic ethyl ester.
Notizen: Rb8AlO4Au3 ≡ Rb5AlO4 · 3RbAu – ein Aluminat-Aurid/ Rb8AlO4Au3 ≡ Rb5AlO4 · 3RbAu – an Aluminate Auride
Authors: Mudring Anja-Verena , Jansen Martin
Published: August 2018

Rb8AlO4Au3 (Pearson-Code oP64, P212121, a = 1043.4(1), b = 1296.7(2), c = 1320.2(2) pm, Z = 4,809 reflections with Io > 2δ(I), R1 = 0.059, wR2 = 0.151) is a further, completely new representative belonging to the group of composite alkali metal aurides. It consists of structural elem ents of alkali orthoaluminates and alkali aurides. Indeed, Rb8AlO4Au3 is thus better represented by the formula Rb5AlO4·3RbAu.
Notizen: Synthesis and Structure of YbPdSn2
Authors: Kußmann Dirk , Pöttgen Rainer
Published: August 2018

New ternary stannide YbPdSn2 was synthesized from the elements in a sealed tantalum tube in a high-frequency furnace. YbPdSn2 was characterized through X-ray powder and single crystal data: Cmcm, a = 442.4(2), b = 1108.6(3), c = 738.4(2) pm, wR2 = 0.0450, 317 F2 values, and 16 variable parameters. YbPdSn2 crystallizes with the MgCuAl2 type structure, a ternary ordered variant of the Re3B type. The tin sublattice of YbPdSn2 corresponds to a distorted lonsdaleitelike arrangement with Sn-Sn distances varying from 303 to 336 pm.
Secondary Bonding Interactions in Some Dichloroanilinium Chlorides
Authors: Gray Lilian , Jones Peter G.
Published: August 2018

Of the six structures presented here, five involve clearly defined hydrophilic layers built up from classical hydrogen bonding systems. Of three solvent-free structures, 2,4- and 3,5-dichloroanilinium chlorides both form ribbon structures involving annelated R2
4 (8) rings with NH2 donors (two hydrogen atoms from the positively charged NH3 groups) and chloride acceptors. The ribbons are linked by weaker interactions to form layers. 2,5-Dichloroanilinium chloride forms a layer structure directly, with rings R3
6 (12) exactly analogous to those previously observed in 2-chloroanilinium chloride. 2,6-Dichloroanilinium chloride methanol solvate forms a different type of ribbon structure, with alternating R2
4 (8) and R4
6 12) rings; the latter involve two chlorides, two NH2 groups and two methanols. These ribbons too are linked to form layers. 2,3-Dichloroanilinium chloride hydrate forms layers with two types of ring R3
5 (10); one involves two NH2, two chlorides and the OH part of a water, whereas in the other, an NH2 is replaced by OH2. In all these structures the aromatic groups project approximately perpendicular to the layers to form hydrophobic regions; for all except 3,5-dichloroanilinium chloride, neighbouring layers are linked by weaker interactions such as C-H···Cl hydrogen bonds or Cl···Cl contacts. The final structure, 3,5-dichloroanilinium chloride 1/4-hydrate, is completely different; it involves two types of columns, one built up from quadrilaterals of Cl···Cl contacts between cations and the other consisting of “nanotubes ’ of NH3 groups and chloride anions linked by two- and three-centre hydrogen bonds. The columns are in turn linked by cation-anion Cl···Cl interactions.
Experimental and Theoretical Study on the Structure of Nitramide H2NNO2
Authors: Häußler Angelika , M. Klapötke Thomas , Piotrowski Holger
Published: August 2018

Nitramide was investigated by multinuclear NMR spectroscopy, X-ray-diffraction and computational methods. The crystal structure analysis at various temperatures reveals a planar conformation of the molecule with a N-N bond length corresponding to a bond order between one and two. Hydrogen bonds connect the nitramide molecules side-on and end-on. This leads to the formation of layers in the crystal. Calculations were performed to explain the shorter N-N bond length in the crystal compared to the gas phase. The nitramide trimer is used as a model.
Synthesis and Structure of trans-Dichloro-tetra(pyrazole)-gallium(III) Chloride and Tetrachlorogallate(III)
Authors: Nogai Stefan , Schier Annette , Schmidbaur Hubert
Published: August 2018

[GaCl2(pyrazole)4]+Cl- and [GaCl2(pyrazole)4]+GaCl4
- are formed in the reaction of pyrazole and anhydrous gallium trichloride in toluene/diethyl ether. The crystal structure of the chloride salt shows cations in a trans-conufiguration which are associated with the chloride counterions through N-H- -Cl hydrogen bonds.
Hydroboration and Haloboration of Propyne and 1-Butyne
Authors: Bayer Michael J. , Pritzkow Hans , Siebert Walter
Published: August 2018

Hydroboration of propyne and 1-butyne with HBCl2 obtained from BCl3 and Me3SiH in equimolar amounts leads to 1,1-bis(dichloroboryl)alkanes 1. When BCl3 is used in excess, no 1,1-bis(dichloroboryl)alkanes 1 but E-1-dichloroborylalkene 2 besides E-1-dichloroboryl-2- chloro-alk-1-ene 3 are formed. Other by-products are tris(2-chloro-alk-1-ene-1-yl)borane 4 and bis(2-chloro-alk-1-ene-1-yl)chloroborane 5. The reaction of 3 with catechol and the formation of pyridine adducts of 4 and 5 lead to crystalline products. The composition of the products was determined by NMR spectroscopy, MS spectrometry and X-ray structure analyses of 6a, 6b, 7a and 8b.
Excited State Behavior of Uranyl Complexes with Salophen and Oxine as Chromophoric Ligands
Authors: Kunkely Horst , Vogler Arnd
Published: August 2018

The electronic spectra and the photochemistry of the uranyl complexes UO2 (salophen) and UO2 (oxinate)2 with H2salophen = N,N´-bis(salicylidene)-o-phenylenediamine and oxine = 8- hydroxyquinoline were studied. The excited state behavior of both complexes is determined by a low-energy salophen2- / oxinate- to U(VI) ligand-to-metal charge transfer (LMCT) state which is not luminescent but can be reactive. In the case of UO2 (oxinate)2 the photolysis leads to the formation of free oxine with ϕ = 3.6 x 10-3 at λirr = 366 nm in CHCl3. It is suggested that various redox processes with the participation of the solvent are involved in product formation. UO2 (salophen) is not light sensitive since the primary electron transfer is followed by recombination which is facilitated by the rigid UO2(salophen) structure.
5-(2-Methylphenyl)-4-pentenoic Acid from a Terrestrial Streptomycete
Authors: Mukku Venugopal J. R. V. , Maskey Rajendra P. , Monecke Peter , Grün-Wollny Iris , Laatsch Hartmut
Published: August 2018

From a terrestrial Streptomycete, GW 10/2517, the new 5-(2-methylphenyl)-4-pentenoic acid (1a) was isolated. The structure of 1a was proven by a detailed spectroscopic analysis and by synthesis.
N-Arylsulfonyl-benzimidazolones as Potential Hypoglycemic Agents
Authors: Ahmad Iftikhar , Hameed Shahid , Duddeck Helmut , Lenzen Sigurd , Rustenbeck Ingo , Ahmad Roshan
Published: August 2018

1,3-Bis(arylsulfonyl)-benzimidazolones 1a-d were synthesized by reacting benzimidazolones with arenesulfonyl chlorides in the presence of NaOH. Mono(arylsulfonyl)-benzimidazolone derivatives 5a-c were prepared from benzimidazolone by protecting one of the Natoms with a tert-butoxycarbonyl group followed by arylsulfonylation and deprotection in acidic medium. The antidiabetic activity of three compounds 1a, 1c and 5a has been determined.
Hydrogen Bonding of 2-Tetrazenes, 2. Synthesis and Structural Studies of Hydroxyalkyl-Substituted 2-Tetrazenes
Authors: Porath Bernd , Rademacher Paul , Boese Roland , Bläser Dieter
Published: August 2018

Five hydroxyethyl-2-tetrazenes (1 - 5) and their methyl ethers (6 - 10) have been synthesized and hydrogen bonding in these compounds has been investigated by theoretical and spectroscopic (IR, 1H NMR, 15N NMR) methods. The structure of 1,1,4,4-tetrakis(2-hydroxyethyl)- 2-tetrazene (4) was determined byX-ray diffraction analysis. Several conformationswith intramolecular hydrogen bonds were investigated by ab initio B3LYP as well as semiempirical SCF calculations. In all cases, conformers with OH- - -N hydrogen bonds with azo nitrogen atoms as acceptors (conformers A, B, C) are found as most stable. Incompounds with small or flexible N1- and N4-substituents R besides the hydroxyethyl group (3, 4), hydrogen bonds forming six-membered rings, with the R groups taking syn positions at the N1-N2 and N3-N4 bonds (conformer A), are preferred over those with seven-membered rings and R taking anti positions (conformer B). Steric interaction in the other compounds (1, 2, 5) leads to destabilization of conformers A and conformers B become more stable. A special case is presented by compound 4 which has only hydroxyethyl substituents on the 2-tetrazene unit. In the most stable conformer (4C) there are two OH- - -O and one OH- - -N hydrogen bonds. By IR solution measurements intra- and intermolecular hydrogen bonds could be distinguished. Association shifts Δδ measured by 1H NMR spectroscopy, indicate that the investigated compounds exhibit comparable association properties with intermolecular association clearly prevailing. 15N NMR spectra of compounds 1 - 10 in two solvents have been measured if solubility was sufficient. The data indicate that all nitrogen atoms of 1 - 5 participate in H bonding. In the crystalline state, molecules 4 adopt a conformation without intramolecular H bonds (4D) and are associated by intermolecular OH- - -O hydrogen bonds that form a three-dimensional network. An untypical decomposition pattern was discovered for benzyl derivatives 5 and 10.
Sultam and Sultim Structures, Part 2. Functionalized Novel Cyclic Sulfin- and Sulfonamides: A Comparison of Hydrogen Bonding Formation in Sulfoxides and Sulfones
Authors: Schulze Bärbel , Taubert Kathleen , Gelalcha Feyissa Gadissa , Hartung Christine , Sieler Joachim
Published: August 2018

The stable hydroperoxides rac-cis-2a,d and 4a,c were synthesized by oxidation of the salts 1. The 3-hydroxy sultims rac-cis-3a,b and sultams 5a,e were obtained by reduction of the corresponding hydroperoxides 2 and 4. Crystal structure analyses were performed for compounds 3b, 4a, 5a, 5e and revealed a variety of intermolecular contacts leading to cyclodimers, tetramers and polymers. In carboxylic esters 4a and 5a, cyclodimers with a 20- or 22-membered ring are formed via ‘head-to-tail’ CO⋯H-O hydrogen bonds and π/π-interactions, without participation of the SO2 group. The 1,1-dioxide 4c, which has no carbonyl substituent, forms a tetrameric unit by combining two symmetry independent molecules through strong OO-H⋯O-S-O and short nonclassical O-S-O⋯H-C hydrogen bonds. The sultam 1,1-dioxide 5e, bearing a highly substituted 2-phenyl ring, exhibits in the solid state strong intermolecular O-S-O⋯H-O hydrogen bonds and forms the first polymer chain in this cyclic sulfonamide series. In sultims 2a, 3a and 3b, but not in 2d, strong intermolecular S-O⋯H-O hydrogen bonds are observed and polymer chains originate from the c-glide plane (space group P21/c)in 2a and from two symmetry independent molecules in 3a. In the 1-oxide 2d a ‘head-to-head’ dimer was found with two strong SO⋯H-OO hydrogen bonds in a 14- or 16-membered ring. Short nonclassical C-H⋯O-C interactions connect the dimers to form polymeric chains.
Stereoselective Synthesis of 5-[(Z)-Heteroarylmethylidene] Substituted Hydantoins and Thiohydantoins as Aplysinopsin Analogs
Authors: Jakšea Renata , Krošelj Vesna , Rečnik Simon , Soršak Gorazd , Svete Jurij , Stanovnik Branko , Grdadolnik Simona Golič
Published: August 2018

3-Substituted 5-[(Z)-heteroarylmethylidene]imidazolidine-2,4-dione and 5-[(Z)-heteroarylmethylidene]- 2-thiooxoimidazolidin-4-one derivatives were prepared stereoselectively by coupling of 5-(dimethylamino)methylidene substituted hydantoin and thiohydantoin derivatives with carbocyclic and heterocyclic C-nucleophiles.Configuration around the exocyclic C=C double bond was determined by NMR, using NOESY and 2D HMBC techniques.
Structure and Magnetism of REPtMg (RE = Pr,Nd, Sm)
Authors: Kraft Rainer , Kotzyba Gunter , Hoffmann Rolf-Dieter , Pöttgen Rainer
Published: August 2018

New magnesium based intermetallic compounds PrPtMg, NdPtMg and SmPtMg were synthesized from the elements by reaction in sealed tantalum tubes in a high-frequency furnace. The three compounds were investigated by X-ray powder and single crystal diffraction: ZrNiAl type, space group P6̄2m, a = 752.34(8), c = 412.66(4) pm, wR2 = 0.0668, 341 F2 values, 14 variables for PrPtMg, a = 748.80(8), c = 411.52(4) pm, wR2 = 0.0521, 196 F2 values, 14 variables for NdPtMg and a = 743.90(5), c = 409.80(3) pm, wR2 = 0.0489, 248 F2 values, 12 variables for SmPtMg. From a geometrical point of view these structures are composed of two types of platinum centered trigonal prisms, i. e. [Pt1Mg3RE6] and [Pt2Mg6RE3]. These prisms are condensed via common edges and faces. Together the platinum and magnesium atoms build three-dimensional [PtMg] networks in which the rare earth atoms are located in distorted pentagonal channels. Magnetic susceptibility data of PrPtMg show Curie-Weiss behaviour with an experimentalmagnetic moment of 3.59(2) μB and a paramagnetic Curie temperature of 7.5(5) K. Ferromagnetic ordering is detected at TC = 8.0(5) K with a magnetic moment of 1.75(5) μB/Pr at 4.5 K and 5 T. SmPtMg orders ferromagnetically below 52(1) K with a presumably complex spin structure in the ordered state.
A New Strontium Lithium Titanium Oxide, SrLi2Ti6O14: Crystal Growth and Structure Determination
Authors: Koseva I. , Peshev P. , Pechev S. , Gravereau P. , Chaminade J.-P.
Published: August 2018

A new strontium lithium titanate with composition SrLi2Ti6O14 has been discovered in the ternary system SrO - Li2O - TiO2. Single crystals of this compound have been grown by the flux method. The structure of SrLi2Ti6O14 has been solved using X-ray data (Mo-Kα radiation, orthorhombic, space group Cmca, Z = 8, with a = 16.570(5), b = 11.150(2), c = 11.458(2) Å , R1 = 0.039 (wR2 = 0.087)). The crystal structure is built by edge and corner sharing TiO6 octahedra which form layers parallel to the (100) plane. Consecutive layers [deduced from a mirror plane parallel to (100)] are linked by common corners in the a direction. Lithium atoms in tetrahedral coordination occupy vacancies of the framework of titanium octahedra, while strontium atoms lie in 11-coordinated sites between two successive layers.
III. Thioanalogs of Sparteine Lactams. (+)-17-Thionosparteine and its Perchlorate Salt
Authors: Wysocka Waleria , Kolanoś Renata , Borowiak Teresa , Dutkiewicz Grzegorz
Published: August 2018

(+)-17-Thionosparteine and its perchlorate have been obtained and characterized by IR and NMR spectroscopy as well as by X-ray diffraction analysis. Introduction of the thiolactam group into the cis-quinolizidine system causes conformational rigidity of this fragment. Moreover, the conformations in solution and in the solid state are the same.
Neue Oxopnictate AI
3MVO4: Darstellung und Kristallstruktur von A3AsO4 (A = K, Rb, Cs) und K3BiO4 / New Oxopnictates AI
3MVO4: Synthesis and Crystal Structure of A3AsO4 (A = K, Rb, Cs) and K3BiO4
Authors: Emmerling Franziska , Idilbi Mamdouh , Röhr Caroline
Published: August 2018

Abstract The title compounds have been synthesized via oxidation of the elemental pnicogenes (M = As, Bi) with the hyperoxides AO2 (A = K, Rb, Cs) and their crystal structures were determined on the basis of single crystal X-ray data. In K3AsO4 (orthorhombic, Cccm, a = 1060:1(1), b = 1135:2(1), c = 1694:0(2) pm, Z = 16) and Cs3AsO4(orthorhombic, Pnma, a = 1254:3(2), b = 902:9(2), c = 658:5(3) pm, Z = 4) isolated tetrahedra [AsO4]3- with distances As-O between 167.0 and 170.5 pm are present, which are arranged in a nearly cubic close packing. The structure of K3BiO4 (triclinic, P1̄, a = 643:18(6), b = 657:27(6), c = 762:41(7) pm, α = 101:724(2)°, β = 96:472(2)°, γ = 105:465(2)°, Z = 2) contains centrosymmetric dimers [O3BiO2BiO3]6-, in which the Bi(V) atoms are surrounded by five O atoms in a distorted trigonal bipyramidal geometry with distances Bi-O in the range of 199.5 to 233.1 pm.
Gold(I) Carboxylates and Fluorocarboxylates
Authors: Römbke Patric , Schier Annette , Schmidbaur Hubert
Published: August 2018

Keywords

(Triphenylphosphine)gold(I) pivalate (1), and (triphenylphosphine)gold(I), [tri(p-tolyl)-phosphine]gold(I), [(4-dimethylaminophenyl)diphenylphosphine]gold(I), and (cyclohexylisocyanide) gold(I) pentafluoropropionate (2 -5) have been prepared from the corresponding gold(I) halide complexes and silver carboxylates in high yields. The products are stable to air and moisture and soluble in most common polar organic solvents. The structures of 1 and 3 have been determined. Owing to the bulk of the carboxylate substituents the molecules are monomers in the crystal. Compounds 1 - 4 undergo thermal decomposition in a narrow temperature range around 130°C, 5 is less stable and decomposes at 48° C.
Hetero-Diels-Alder Reactions of Enaminothione with Electrophilic Olefins. Synthesis of 2-Furyl Substituted 2H-Thiopyrans
Authors: Bogdanowicz-Szwed Krystyna , Budzowski Artur
Published: August 2018

The hetero-Diels-Alder reaction of 1-(2-furyl)-3-(dimethylamino)-2-propene-1-thione (diene) with maleic and fumaric acids, and β-nitrostyrenes yielded 3,4-dihydro-2H-thiopyran derivatives. Treatment of some of those cycloadducts with acetic acid caused elimination of dimethylamine yielding stable 2H-thiopyrans. Reaction of the diene with maleic anhydride furnished a cycloadduct which underwent spontaneous rearrangement to form an N,N-dimethylamide derivative. Cycloadditions of the diene to maleimide, N-phenylmaleimide, diethyl maleate, fumarate and butenolide, carried out in the presence of acetic anhydride,were followed by elimination of dimethylamine, afforded stable 2H-thiopyran derivatives.
Crystal Structure and Vibrational Behaviour of Tetraaqua-di(nicotinamide)M(II)-Saccharinates, with M(II) = Co, Ni, Zn
Authors: Castellano Eduardo E. , Piro Oscar E. , Parajón-Costa Beatriz S. , Baran Enrique J.
Published: August 2018

The crystal structures of [M(nic)2 (H2O)4](sac)2 (nic = nocotinamide; sac = saccharinate anion) with M = Co(II), Ni(II) and Zn(II), have been determined at 116 K by single-crystal X-ray diffractometry. The compounds crystallize in the triclinic space group P1̅ with Z = 1, and the M(II) cations present a slightly distorted MN2O4 octahedral environment, with equatorially coordinated water molecules and axially pyridine N-bound nicotinamide ligands. The saccharinate anions act as counteranions, and are not part of the first coordination sphere. Some comparisons with related structures have been made and the most important features of their IR spectra discussed.
Novel Nitronyl Nitroxides: Synthesis and Properties
Authors: Greve Stefan , Vill Volkmar , Friedrichsen Willy
Published: August 2018

The synthesis of several new nitronyl nitroxides with mesogenic groups is reported (6a, b, 11, 14a, b). Microscopic investigations revealed that in some cases (6b, 14b) highly ordered mesogenic phases are formed.
Reactivity Trends in the Reaction of Alkynes with 3-Oxo-camphorsulfonylimine
Authors: Santos A. Mafalda , Carvalho M. Fernanda N. N. , Galvão Adelino M. , Pombeiro Armando J. L.
Published: August 2018

The regioselective addition of deprotonated alkynes (phenyl-1-propyne, propargyl ether or tetrahydropyran-protected 3-butyn-1-ol) to the imine group was identified as a competitive process to the nucleophilic addition to the keto group of (1S)-3-oxo-camphorsulfonylimine. The selectivity of the process depends on the characteristics of the nucleophile and the reaction conditions. In the case of propargyl ether it was possible to render the imine addition the main process.

The structural characterization of compounds 1, 2, 6 by X-ray diffraction analysis show that the C2 - C3 bond becomes longer upon nucleophilic addition to the imine group of (1S)-3-oxo-camphorsulfonylimine. This trend is believed to favour the ring opening process that undergoes the formation of the spiro type compound 7.
A Facile One-Pot Synthesis of 1,4,7,8,9,10-Hexahydro-6H-[1]- benzothieno[2', 3', :4,5]pyrimido[1,2-b][1,2,4,5]tetrazin-6-ones
Authors: Abdallah Magda A.
Published: August 2018

1,4,7,8,9,10-Hexahydro-6H-[1]benzothieno[2’,3’:4,5]pyrimido[1,2-b][1,2,4,5]tetrazin-6-ones were prepared via reaction of 2,3,5,6,7,8-hexahydro-3-amino-2-thioxo[1]benzothieno[2,3-d]- pyrimidin-4(1H)-one or its 2-methylthio derivative with hydrazonoyl halides in ethanol in the presence of triethylamine. Some of the products were screened for their biological activity.
Synthesis, Characterisation and Crystal Structure of a Cyano-Bridged Polymeric Yttrium-Iron Complex {[Y(phen)2(H2O)2Fe(CN)6]·8H2O}n
Authors: Karan Nirmal Kumar , Mitra Samiran , Hossain G. M. Golzar , Malik K. M. Abdul
Published: August 2018

A new cyano-bridged 1D polymeric linear chain complex {[Y(phen)2(H2O)2Fe(CN)6]ּ 8H2O}n (where phen = 1,10-phenanthroline) has been synthesised and its crystal structure determined. The yttrium(III) and iron(III) centres achieve distorted square antiprismatic and slightly distorted octahedral geometry, respectively. Presence of an extensive network of hydrogen bonds present in the complex impart the overall stability to the system. The presence of ten water molecules per molecular unit has been confirmed by thermogravimetric analysis.
Metallkomplexe mit biologisch wichtigen Liganden, CXLVI [1]. Bis(allyl)-N,O-α-Aminocarboxylat-Rhodium-Komplexe / Metal Complexes of Biologically Important Ligands, CXLVI [1]. Bis(allyl)-N,O-α-Aminocarboxylate-Rhodium Complexes
Authors: Ponikwar Walter , Mayer Peter , Beck Wolfgang
Published: August 2018

The reactions of [(η3-C3H5)2Rh-μ-Cl]2 with the anions of α-amino acids (glycine, L-alanine, L-valine, L-isoleucine, L-proline, L-phenylalanine, L-phenylglycine, L-thyrosine) afford the N,O-chelates (η3-C3H5)2Rh(α-amino carboxylate). For complex (η3-C3H5)2Rh(glycinate) dynamic behaviour in solution could be observed by 1H NMR. The structure of (η3-C3H5)2Rh(L-prolinate) was determined by X-ray diffraction.
Synthesis of SrxBa(1-x)TiO3 Solid Solutions from the Mechanically Activated System BaCO3 - SrCO3 - TiO2
Authors: Berbenni V. , Marini A.
Published: August 2018

Mixtures xSrCO3 (1 - x)BaCO3 TiO2 (0 < x < 1) have been mechanically activated by high energy milling in order to promote the formation of mixed (Sr,Ba) carbonate that decomposes, in a single stage, at temperatures generally lower than for the corresponding physical mixtures. By annealing such milled mixtures at high temperatures (≈ 1000 °C), cubic solid solutions SrxBa(1-x)TiO3 are obtained (except at x = 0.1 where a tetragonal solid solution forms) whose lattice parameters decrease linearly with x. The enthalpy of solid solution formation changes with composition showing higher values in the x range between x = 0.2 and 0.5 where the reaction has been demonstrated to occur via the formation of Ba2TiO4. By contrast, the enthalpy values decrease for x > 0.5.
Crystal Structures of Seven Terephthaldiamide Derivatives
Authors: Jones P. G. , Ossowski J. , Kus P.
Published: August 2018

N,N′-Dibutyl-terephthaldiamide (1), N,N′-dihexyl-terephthaldiamide (2), N,N′-di(tert-butyl)- terephthaldiamide (3), N,N,N′,N′-tetrabutyl-terephthaldiamide (4), 1,1′-terephthaloylbis- pyrrolidine (5), 1,1′-terephthaloyl-bis-piperidine (6), and 4,4′-terephthaloyl-bis-morpholine (7) have been synthesised and physicochemically characterised. The X-ray structure determinations reveal imposed inversion symmetry for compounds 1-6; compound 3 has two independent molecules with inversion symmetry in the asymmetric unit. Compounds 1-3 form classical hydrogen bonds of the type N-H···O=C, leading to a ribbon-like arrangement of molecules (1 and 2) or a layer structure (3). Compound 3 also displays a very short C-H···O interaction, a type of hydrogen bond that is also observed in compounds 4-7, which lack classical donors; thereby compounds 4-6 form layer structures and 7 a complex threedimensional network.
Steroids and Terpenoids from Ajuga relicta
Authors: Kökdil Gamze , Topc̡u Gülac̡tı , C.Görenc Ahmet , Voelterd Wolfgang
Published: August 2018

From the acetone extract of Ajuga relicta P. H. Davis, four steroids, two being new ones, (24S)-24-ethylcholesta-5,25-diene-11α-hydroxy-1-one (1) and (24S)-24-ethylcholesta-5,25- diene-7α-hydroxy-3-one (2), two known triterpenoids and two known diterpenoids were isolated in addition to a monoterpene and an iridoid. The structures were characterized by spectral methods including UV, IR, 1H, 13C NMR spectroscopy and mass spectrometry.
Notizen: Montmorillonite K-10 as Highly Efficient and Mild Catalyst for Deprotection of Ketone Dimethylhydrazones Using Microwaves in a Solventless System
Authors: Hosseinzadeh Rahmam , Sharifi Ali , Mirzaei Mojtaba , Heydar Kourosh Tabar
Published: August 2018

N,N-Dimethylhydrazones of ketones were efficiently and rapidly deprotected to the corresponding ketones by Montmorillonite K-10 clay using microwave irradiation under solvent free conditions.
Synthesis and Characterization of Chromium Tricarbonyl Complexes of 1-Phenylgermatrane and 1-Phenylazagermatrane. Crystal Structure of [N(CH2CH2O)3GeC6H5]Cr(CO)3
Authors: Karlov Sergey S. , Sorokin Denis A. , Oprunenko Yuri F. , Lorberth Jörg , Zaitseva Galina S.
Published: August 2018

The reaction of 1-phenylgermatrane (1) and 1-phenylazagermatrane (2) with Cr(CO)6 affords chromium tricarbonyl complexes [N(CH2CH2O)3GeC6H5]Cr(CO)3 (6) and [N(CH2- CH2NH)3GeC6H5]Cr(CO)3 (7). In contrast, the same reaction of Cr(CO)6 with 1-(9-anthracenyl) germatrane (3) does not proceed. Composition and structures of the 6 and 7 were established by elemental analyses, 1H and 13C NMR spectroscopy and mass spectrometry. The crystal structure of 6 is reported
Zur Reaktion von PCl3 mit NaR*, KR* und ZnR*2 (R* = SitBu3) [1]: Bildung des Diphosphens R*P=PR*, Tetraphosphans P4R*
2 , Tetraphosphanids NaP4R*
3 sowie von Halogenphosphanen R*
mPmClp / On the Reaction of PCl3 with NaR*, KR* and ZnR*2 (R*= SitBu3) [1]: Formation of the Diphosphene R*P=PR*, Tetraphosphane P4R*2, Tetraphosphanide NaP4R*3 as well as Halogenophosphanes R*mPnClp
Authors: Wiberg Nils , Wörner Angelika , Lerner Hans-Wolfram , Karaghiosoff Konstantin
Published: August 2018

The reaction of PCl3 at r. t. with an equimolar amount of NaR* in heptane gives the colorless phosphane R*PCl2 (1), the colorless diphosphane R*ClP-PClR* (2), the light green diphosphene R*P=PR* (4), the cyclotetraphosphane R*2P4Cl2 (6) (not isolated), the light yellow bis(cyclotriphosphanyl) P6R*4 (7), the cyclotriphosphane R*2P3Cl (8) (not isolated), and the colorless bicyclophosphane P4R*2 (9).With a threefold molar amount of NaR* in tetrahydrofuran the blue violet triphosphanide NaP3R*2 (10), the dark red tetraphosphanide NaP4R*3 (11), and the orange pentaphosphanediide Na2P5R*3 (12) are formed from PCl3 besides the phosphanides NaPR*2, Na2PR* (isolated), NaP2R*3 and Na2P2R*2. With a four-fold molar amount of KR* in benzene PCl3 gives the green diphosphanediide K2P2R*2 and the red phosphanediide K2PR*, and with an equimolar amount of ZnR*2 in heptane the compounds 1, 2, 4, 7 and 8 are obtained. The compound R*P=PR* (4), the first diphosphene with two silyl substituents, is formed in high yields from the action of Na on R*PCl2 in heptane at 90 "C. It gives a [2+4] cycloadduct with 2,3-dimethylbutadiene and phosphanides (Na2P2R*2 or Na2PR*) with Na or NaR*. Bicyclotetraphosphane P4R*2 (9) (structure: two R*P3 rings with a common edge) is exclusively obtained from Na2P4R*2 (formed quantitatively from P4 and 2 NaR*) and TCNE. 9 may be reduced (Na, THF) with reformation of Na2P4R*2 and reacts in the presence of NaR* with formation of dark red NaP4R*3 (11) (structure: P3 ring with two R* substituents in trans position and one PNaR* substituent). Straightforward syntheses of halogenophosphanes include (i) reactions of ZnR*2 with PCl3 or PBr3 (mole ratio 1 : 2) in heptane to form R*PCl2 (1) or R*PBr2, and (ii) reaction of R*2 with R*PCl2 (mole ratio 1 : 2) without a solvent, or of KR* and PCl3 (mole ratio 2 : 1) in benzene to formR*ClP-PClR* (2). The halogenophosphanes R*2P3Cl (8) (structure: P3 ring with two R* substituents in trans position and one Cl substituent) as well as R*2P4Cl2 (6) (structure: P4 ring with alternating R* and Cl substituents) have not been isolated. The 31P-NMR spectra and the pathways of formation of the phosphorus compounds are discussed
Hydrothermal Single Crystal Growth and Crystal Structures of the Mercury(II) Selenates(VI) HgSeO4, HgSeO4·HgO and HgSeO4·2HgO
Authors: Weil Matthias
Published: August 2018

Colourless single crystals of HgSeO4 were prepared under hydrothermal conditions by reacting yellow HgO in concentrated selenic acid at 250 °C (10 d); yellow crystals of HgSeO4 HgO and red-brown crystals of HgSeO4 2HgO were obtained during hydrolysis of the so prepared HgSeO4 in demineralized water at 200 °C (7 d). All crystal structures were solved and refined from single crystal diffractometer data sets. The structures of HgSeO4 and HgSeO4 2HgO are isotypic with the corresponding sulphates. They are based on [HgO7] polyhedra with a [4+3] coordination around the mercury atom and isolated SeO4
2- tetrahedra for HgSeO4, as well as hexagonal [Hg3O2]2+ nets perpendicular to [001] and disordered SeO42- tetrahedra in the interstices of the nets for HgSeO4 2HgO. The hitherto unknown compound HgSeO4 HgO crystallizes in a new structure type. The main structural features of this compound are 1
∞[O-Hg-O] zigzag chains which extend parallel to [010] and are built of two crystallographically independent Hg and O atoms, isolated SeO4
2- tetrahedra situated between the chains and [HgOx] polyhedra (x = 6 and 7) connecting both building units via common oxygen atoms
Magnesium Isotope Effects by Ion Exchange Using Monoazacrown Bonded Merrifield Peptide Resin
Authors: Kim Dong Won , Ryu Hai Il , Jeon Byeong Kwang
Published: August 2018

Magnesium isotope effects by ion exchange using monoazacrown (1-aza-18-crown-6) bonded Merrifield peptide resin were investigated. The capacity and distribution coefficient were determined. The separation factors, (24Mg2+/25Mg2+)Resin/(24Mg2+/25Mg2+)Solution, (24Mg2+/26Mg2+)Resin/(24Mg2+/26Mg2+)Solution, and (25Mg2+/26Mg2+)Resin/(25Mg2+/25Mg2+)Solution were 1.0071, 1.0132, and 1.0068, respectively. The heavier magnesium isotopes were enriched in the solution phase, while the lighter isotopes were enriched in the resin phase. It was found that the hydration and isotope mass effects are more significant than that of the complexation
Synthese, Kristallstruktur und Spektroskopische Charakterisierung des Phosphaniminato-Komplexes [Cl2AlNPCl3]2 und des Phosphanimin-Komplexes [Me3SiNPCl3 · AlCl3]/Synthesis, Crystal Structure, and Spectroscopic Characterization of the Phosphorane Iminato Complex [Cl2AlNPCl3]2, and of the Phosphane Imine Complex [Me3SiNPCl3 · AlCl3]
Authors: Jächke Britta , Jansen Martin
Published: August 2018

Reaction of Me3SiNPCl3 with AlCl3 yields the donor-acceptor complex [Me3SiNPCl3 · AlCl3] (1). Thermal treatment of 1 and simultaneously removing the by-product Me3SiCl results in the formation of [Cl2AlNPCl3]2 (2). Crystallization of 2 from CH2Cl2 yields colorless crystals which have been characterized by single crystal X-ray diffraction analysis (P1̄, a = 719.1(2), b = 843.5(2), c = 857.4(2) pm, α = 64.23(1), β = 76.62(1), γ = 68.21(1)°, Z = 1, R1 = 0.0498). The molecule exhibits site symmetry Ci (point group approximately C2h) and shows as a characteristic feature a planar, almost square Al2N2 four-membered ring with Al-N distances of 187.5(3) and 187.9(3) pm. The phosphorus atoms of the PCl3-groups attached to the nitrogen atoms are almost located in the same plane as defined by the Al2N2-ring. Both new compounds have been characterized by IR, NMR, and MS spectroscopy.
Magnetic Exchange Based on π-π Stacking Interactions: Synthesis, Crystal Structure, Thermal Decomposition and Magnetic Properties of [Ce(phen)2(H2O)2(NO3)2](NO3)(phen)2(H2O)
Authors: Zheng Yue-Qing , Zhou Lin-Xia , Lin Jian-Li , Wei Dan-Yi
Published: August 2018

Reaction of Ce(NO3)3·6H2O and 1,10-phenanthroline in CH3OH / H2O afforded the title compound [Ce(phen)2(H2O)2(NO3)2](NO3)(phen)2(H2O), which consists of [Ce(phen)2- (H2O)2(NO3)2]+ complex cations, NO3
- anions, phen and crystal water molecules. Within the [Ce(phen)2(H2O)2(NO3)2]+ complex cations, the Ce atoms are 10-fold coordinated by four pyridyl N atoms, four nitrato O and two water O atoms with d(Ce-O) = 2.505 - 2.629 and d(Ce-N) = 2.666 - 2.734 Å. The supramolecular assemblies of the complex cations via π-π stacking interactions form 1D columnar chains, which run parallel to give positively charged 2D layers. The phen molecules are also assembled via π-π stacking interactions into 1D columnar chains whose arrangement results in neutral 2D layers. The NO3
- anions and the crystal water molecules are situated between the positively charged and neutral 2D layers. The title compound decomposes in four steps upon heating. Magnetic measurements show that it is a ferrimagnet at low temperature and follows the Curie-Weiss law χm(T - θ) = 0.796 (cm3 mol-1 K) with the Weiss constant θ = -57(2) K over the temperature range 50 - 300 K. Comparison of the magnetic behavior of the title cerium complex with that of the Pr and Tb phen nitrato complexes of the formula Ln(phen)2(NO3)3 (Ln = Pr, Tb) suggests that magnetic exchange is probably transmitted via the π-π stacking interactions.
Tetrapodal Pentadentate Ligands with NS4 and NP4 Donor Sets: An Elusive Tetrathiol, and a Sterically Encumbered Tetraphosphane
Authors: Zimmermann Christopher , Bauer Walter , Heinemann Frank W. , Grohmann Andreas
Published: August 2018

With the intention of preparing tetrapodal pentadentate ligands having NS4 or NP4 donor sets, we investigated reactions of the previously reported tetratosylate 2,6-C5H3N[CMe(CH2OTs)2]2 (2) with thiourea or diphenylphosphide, but found them not to proceed cleanly, and to give mixtures of products. A derivative of 2 better suited to nucleophilic substitution is the corresponding tetrabromide 2,6-C5H3N[CMe(CH2Br)2]2(2,6-bis-(2-bromo-1-bromomethyl-1- methyl-ethyl)-pyridine, 3), which is obtained in excellent yield from 2 by treatment with LiBr in dimethylsulfoxide. The reaction of 3 with 4 eq of thiourea in refluxing ethanol gives a single product. Substitution is not quantitative, however, and the product likely is a bis(thiouronium) bis(bromide) salt. Similarly, the reaction of 3 with 4 eq of potassium O-ethyl xanthogenate displaces only two out of the four bromo substituents under the chosen conditions; workup then leads to what is formulated as a bis(thietane) derivative formed by intramolecular cyclisation. By contrast, nucleophilic substitution with NaSEt in ethanol is quantitative, and the thioether 2,6-C5H3N[CMe(CH2SEt)2]2(2,6-bis-(2-ethylsulfanyl-1-ethylsulfanylmethyl- 1-methyl-ethyl)-pyridine, 4) has been isolated in close to 60% yield. Likewise, and in spite of the considerable steric bulk amassed in the molecule, the reaction of 3 with an excess of KPPh2 in THF proceeds smoothly (even at -50 "C), to give the tetraphosphane 2,6-C5H3N[CMe(CH2PPh2)2]2(2,6-bis-{2-(diphenyl-phosphanyl)-1-[(diphenyl-phosphanyl)- methyl]-1-methyl-ethylg-pyridine, 5) in 65% yield. In order to assess possible pathways of oxidative degradation relevant to the coordination chemistry of this ligand, 5 was treated with NO in CH2Cl2 or ether at different temperatures. In two cases, reaction was observed to produce the oxide 2,6-C5H3N[CMe(CH2P(=O)Ph2)2]2 (6) as a colourless solid in near quantitative yield, with concomitant formation of N2O. All compounds have been characterised by 1H, 13C and 31P NMR spectroscopy (as applicable); IR spectroscopic and elemental analysis data are reported, and the crystal structure of 6 has been determined.
Orthoamide, LIX. Formyl-aalen [Tris(diformylamino)methan] – ein neues Formylierungsmittel für aktivierte Aromaten/Orthoamides, LIX. Formyl-aalen [Tris(diformylamino)methane] – a New Formylating Reagent for Activated Aromatic Compounds
Authors: Kantlehner Willi , Haug Erwin , Scherr Oliver , Ziegler Georg
Published: August 2018

In the presence of strong Lewis acids such as aluminum chloride or boron trichloride, formyl-aalen [tris(diformylamino)methane] (3) acts as a formylating reagent for aromatic alkane compounds and aromatic ethers. The orthoamide 3 delivers three formyl groups for the formylation process. Thus toluene, cumene, tert-butylbenzene, hexylbenzene, ο-xylene, ρ-cymene, biphenyl, anisole, diphenylether and 1,3-dimethoxybenzene can be formylated in 1,2-dichloroethane. In these reactions, 3 and aluminum chloride should be used in a molar ratio of 1:6 to 1:9.