bluuebunny/crossref_metadata_2025 huggingface dataset:
The Crystal Structures of 2-(3’-Hydroxypropyl)benzimidazolium Hexa- and Tetrachloroplatinate
Authors: Elmali A. , Elerman Y. , Eren G. , Gümüş F. , Svoboda I.
Published: August 2018

2-(3’-Hydroxypropyl)benzimidazolium (Hhpb) hexa- and tetrachloroplatinate (C10H13N2O)2·[PtCl6] 1 and (C10H13N2O)2·[PtCl4] 2 were synthesized and their crystal structures determined. Compound 1 is monoclinic, space group P21/n, a = 8.800(1), b = 14.389(2), c = 10.264(2) Å, β = 98.540(10)°, V = 1285.3(3) Å3, Z = 2 and Dc = 1.959 g cm−3. Compound 2 is triclinic, space group P1̄, a=7.8480(10), b=9.0460(10), c=9.6980(10) Å ,α =65.420(10), β =68.810(10), γ = 76.770(1)°,V =581.26(4) Å3, Z =1 and Dc =1.969 g cm−3. In both compounds, the Pt atoms reside at a centre of inversion. Compounds 1 and 2 are comprised of 2-(3’-hydroxypropyl)benzimidazolium (Hhpb)+: (C10H12N2O)+ and [PtCl6]2− and [PtCl4]2− ions, respectively, linked by intermolecular hydrogen bonds N...Cl [range from 3.428(3) to 3.584(4) Å ], N···O [2.769(5) Å ] and O···Cl [3.338(4) and 3.321(3) Å ] for 1, and N···Cl [3.162(7) Å ], N···O [2.749(8) Å ] and O···Cl [3.289(6) Å ] for 2.
Comparative Study of Extraction Techniques with Ammonia or Methanol/Water for the Isolation of Ginsenosides Using HPLC/MS
Authors: Nolte Jürgen , Nigge Walter , Hohaus Eberhard , Cho In-Ho , Lentz Harro
Published: August 2018

Roots of ginseng plants have been extracted with liquid ammonia or methanol/water (60:40 v/v). The extracts were characterized by means of a gradient HPLC/MS method and the results were compared with each other. The ginsenosides Rb1, Rb2, Rc, Rd, Re, Rf, Rg1 and Ro including the malonyl ginsenosides m-Rb1, m-Rb2, m-Rc and m-Rd could be identified. Contrary to previous reports suggesting that during the extraction with liquid ammonia malonyl ginsenosides are totally converted to neutral ginsenosides, it could now be demonstrated by use of mass spectrometry that even after an extraction time of 4 h malonyl ginsenosides can be detected. However, the amount of malonyl ginsenosides was reduced by about one order of magnitude.

The neutral ginsenosides were not changed by liquid ammonia. The mass spectrometric detection has been performed by use of the quasi-molecule ion [M+Na]+ and some specific fragment ions.
Orthoamide, LXI [1]. Ein neues leistungsfähiges Verfahren zur Synthese von Orthoamid- Derivaten von Alkincarbonsäuren / Orthoamide, LXI [1]. A New, Efficient Procedure for the Synthesis of Orthoamide Derivatives of Alkyne Carboxylic Acids
Authors: Kantlehner Willi , Kreß Ralf , Mezger Jochen , Ladendorf Sebastian
Published: August 2018

Tris(dimethylamino)ethoxy-methane (3) reacts with 1-alkynes 7a - h to give orthoamides of alkyne carboxylic acids 4a - h.
1,1-Ethylboration Of Di(alkyn-1-yl)Silanes With Two And Three Si-H Functions. New Silacyclopentadienes
Authors: Wrackmeyer Bernd , Tok Oleg L. , Khan Azim , Badshah Amin
Published: August 2018

The reaction of the di(alkyn-1-yl)silanes Me2Si(C≡CSiMe2H)2 1a and Me(H)Si(C≡CSiMe2H)2 1b with triethylborane was studied. In the case of 1a, the 4-ethyl-3-diethylboryl-1,1-dimethyl-2,5- bis(dimethylsilyl)-1-sila-2,4-cyclop entadiene 2a was the sole product. In the case of 1b, the analogous silole 2b was formed along with two other products which were identified as di(alkenyl)silanes 3b and 4b, in which different types of electron-deficient Si-H-B bridges could be detected. All products were characterised by consistent sets of solution NMR data (1H, 11B, 13C and 29Si NMR). The coupling constants 1J(13C,13C) were measured for 2a and calculated by using DFT methods (B3LYP/6-311+G(d,p) level of theory)
Polyethylene Synthesis Catalyzed By Cp2ZrCl2 Supported On Mordenites With Different Physico-Chemical Properties
Authors: Marques Maria de Fátima V. , Lopes Daniela E. B. , Brandão Juliana B. , Henriques Cristiane A.
Published: August 2018

The commercial zeolite sodic mordenite was chemically and thermally treated in order to obtain materials with different physico-chemical properties to be employed as support for the metallocene bis(cyclopentadienyl)zirconium dichloride used for ethylene polymerization. The supports obtained were characterized regarding their chemical composition, textural properties as well as Lewis and Brφnsted sites concentrations. It was verified that the original zeolite without dealumination treatment was the most active catalyst followed by the material dealuminated with steam. All the supported catalysts produced polyethylene with higher molecular weight in relation to that obtained with the homogeneous counterpart
Secondary Metabolites from Marrubium velutinum, Growing Wild in Greece
Authors: Karioti Anastasia , Heilmann Jörg , Skaltsa Helen
Published: August 2018

From the aerial parts of Marrubium velutinum, two new phenylethanoid glycosides, velutinosides III-IV have been isolated together with four known phenylethanoid glycosides, as well as one new acylated flavone and five known flavonoids. The structures of the isolated compounds were established by means of NMR, MS, and UV spectral analyses
Limonoids From Cipadessa Fruticosa
Authors: Leite Ana C. , Fernandes João B. , da Silva M. Fátima das G. F. , Vieira Paulo C.
Published: August 2018

The fruits of Cipadessa fruticosa Bl. afforded two new limonoids: methyl 8α,30α-epoxide-3β - (2’-methylbutyryloxy)-1-oxomeliacate (cipadesin A) and methyl 21,23-dihydro-23-hydroxy-21-oxo- 3β -tigloyloxy-1-oxomeliac-8(30)-enate (febrifugin A), along with the known limonoids cipadesin, khayasin T, febrifugin, ruageanin A and mexicanolide. Their structures were elucidated on the basis of spectroscopic methods
Hydrogen-Bonded Networks Featuring Yttrium(III) Complexes of N,N’-Dimethylurea (DMU): Preparation and Characterization of [Y(DMU)6][YCl6] and [Y(NO3)3(DMU)3]
Authors: Boudalis Athanassios K. , Nastopoulos Vassilios , Raptopoulou Catherine P. , Terzis Aris , Perlepes Spyros P.
Published: August 2018

In order to examine the possibility of using yttrium(III) in the crystal engineering of hydrogenbonded coordination complexes and to compare the molecular and supramolecular YIII/Cl3 or NO3
-/DMU chemistry with the already well-developed LnIII/Cl− or NO3
−/DMU chemistry (LnIII = lanthanide, DMU = N,N’-dimethylurea), compounds [Y(DMU)6][YCl6] (1) and [Y(NO3)3(DMU)3] (2) have been prepared. The structures of both compounds have been determined by single-crystal Xray diffraction. The structure of 1 consists of octahedral [Y(DMU)6]3+ and [YCl6]3− ions. The YIII ion in 2 is nine-coordinate and ligation is provided by three O-bonded DMU ligands and three bidentate chelating nitrato groups; the coordination polyhedron about the metal can be viewed as a distorted, monocapped square antiprism. The [Y(DMU)6]3+ cations and [YCl6]3− anions self-assemble to form a hydrogen-bonded 3D architecture in 1. Most of the hydrogen-bonding functionalities on the components of 2 create also a 3D network. Two motifs of interionic/intramolecular hydrogen-bonds have been observed: N-H···Cl in 1 and N-H···O(NO3
−) in 2. The IR data are discussed in terms of the nature of bonding and the structures of the two complexes
Photoreactivity and Photoluminescence of Aluminum Maltolate
Authors: Kunkely Horst , Vogler Arnd
Published: August 2018

Aluminium maltolate shows a longest-wavelength absorption at λmax = 314 nm which is of the intraligand (IL) type. IL excitation leads to a photodecomposition of the ligand (φ = 0.04 at λirr = 313 nm, in ethanol). While a fluorescence is not observed, Al maltolate displays a phosphorescence in low-temperature glasses (λmax =510 nm at 77 K, in ethanol)
Preparation, Structure and Gold(I) Complexation of p-Xylylene-1,4-diphosphines
Authors: Reiter Stephan A. , Nogai Stefan D. , Schmidbaur Hubert
Published: August 2018

1,4-Dimethyl-2,5-di(phosphinyl)benzene (1) was prepared in high yield in a four-step synthesis from 1,4-dibromo-2,5-dimethyl-benzene. The intermediates with (Et2N)2P and Cl2P groups (2, 3) with the corresponding substitution pattern have been isolated and structurally characterized. All three compounds (1 - 3) adopt a centrosymmetrical conformation with one of the P-X bonds of each X2P group located in the ring plane while the other reaches out from this plane in a roughly perpendicular orientation. Distortions of the ring and its substituents from a standard planar hexagonal geometry are readily explained by invoking steric and inductive effects. The crystal structure of 1,4-dibromo-2,5-dimethyl-benzene has also been determined for reference purposes. Compound 1 was employed as a substrate for auration by tri(gold)oxonium salts of the type {[(R3P)Au]3O}BF4. Hexanuclear complex salts of the type {[(R3P)Au]3P(C6H2Me2)P[Au(PR3)]3}(BF4)2 were obtained in almost quantitative yield with R3P = tBu3P (4) and Ph3P (5). The former (4) has the higher thermal stability, it could be crystallized and its structure determined. It features a conformation in which the xylene plane bisects one of the Au-P-Au angles at both tetrahedrally coordinated central phosphorus atoms placing its methyl groups in sterically least hindered positions. Compound 5 is labile in solution and shows rapid ligand exchange on the NMR time scale. The limited stability has also been confirmed by mass spectrometry. Similar structural details and differences in stability were observed in the related trinuclear gold complexes based on 1-naphthyl-phosphine, which were prepared as reference materials using the same preparative procedure. Of the two compounds {(1-C10H7)- P[Au(PR3)]3}BF4, with R3P = tBu3P (6) and Ph3P (7), the former is the more stable species. In the solid state the cation approaches mirror symmetry in a conformation comparable to that of 4. Compound 7 is thermally labile and shows a rapid ligand exchange in solution.
Chemical Constituents of Coutaportla ghiesbregthiana: Co-Crystallization of Two ent-Nor-Kaurene Diterpenes
Authors: Parra-Delgado Hortensia , Toscano Rubén A. , García-Argaez Aída N. , Martínez-Vázquez Mariano
Published: August 2018

The known nor-diterpene (16R)-ent-17-hydroxy-19-nor-kaur-4-en-3-one and the new norditerpene (16R)-ent-19-nor-kaur-4-en-3-oxo-17-oic acid were obtained as a crystalline mixture from roots of C. ghiesbregthiana. Their structures were deduced by spectroscopic means and confirmed by a X-ray diffraction study of the crystalline mixture. Additionally, ursolic and betulinic acids, skimmin, and sucrose were isolated. This is the first chemical study of a member of the Coutaportla genus.
Efficient, eco-Friendly and Regioselective Method for Thiolysis of 1,2-Epoxides with Diaryl Disulfides in the Presence of Zn/Bi(TFA)3-TBPB or Zn/Bi(OTf)3-TBPB
Authors: Khosropour Ahmad R. , Khodaei Mohammad M. , Ghozati Kazem
Published: August 2018

Diaryl disulfides undergo regioselective ring-opening of 1,2-epoxides in the presence of zinc powder and 3-4 mol-% of bismuth(III) trifluoroacetate or 1 mol-% of bismuth(III) triflate in molten tetrabutylphosphonium bromide (TBPB) to afford the corresponding β -hydroxy thioethers in good to excellent yields.
A New Polymeric Barium-Iron (III) Complex with Chain and Large Ring Structure
Authors: Karan Nirmal Kumar , Samanta Brajagopal , Mitra Samiran , Gramlich Volker
Published: August 2018

The compound {[Ba6(Phen)12(CF3COO)6{Fe(CN)6}2(H2O)8]·6 H2O}n (1) (Phen = 1,10-phenanthroline) has been synthesized and structurally characterized. In the crystal structure, the two consecutive Ba centres are bridged through trifluoroacetate groups and also via cyano groups of [Fe(CN)6]3− and form the zigzag chain resulting the formation of 24-membered ring structure. The Ba-centres are 8-fold coordinated with distorted cubic geometry. Six H2O molecules per asymmetric unit remain in the structure without any direct interaction with the metal atoms but they act in hydrogen bond formation.
A Phenol Glucoside, Uncommon Coumarins and Flavonoids from Pelargonium sidoides DC
Authors: Gödecke Tanja , Kaloga Maki , Kolodziej Herbert
Published: August 2018

Structural examination of the metabolic pool of the aerial parts of Pelargonium sidoides DC has led to the isolation of two new metabolites, 4-allyl-2,5-dimethoxyphenol-1-β -D-glucopyranoside and 6,7-dihydroxycoumarin-8-sulfate, along with a series of uncommon compounds including (2R,3R)-(+)-dihydroquercetin-3-β -glucopyranoside, (2R,3R)-(+)-dihydrokaempferol-3-β - glucopyranoside, fraxetin-7-β -glucopyranoside, 7-methoxycoumarin-6-β -glucopyranoside, umckalin, orientin-2”-gallate, and isoorientin-2”-gallate. They are accompanied by the widespread isoorientin, orientin, fraxetin, (2R,3S)-epigallocatechin-3-gallate, gallic acid and protocatechuic acid. The structures of the compounds were established from spectroscopic studies. Determination of configurations was achieved by circular dichroism.
4,4’-Disubstituted 2,2’-Bipyridines for the Design of Push-Pull Ligands
Authors: Haberecht Monika C. , Bolte Michael , Bats Jan W. , Lerner Hans-Wolfram , Wagner Matthias
Published: August 2018

Starting from 4,4’-dimethyl-2,2’-bipyridine, five new 2,2’-bipyridines symmetrically disubstituted in the 4,4’-positions with either terminal alkenyl, (trimethylsilyl)aryl- or (trimethylsilyl)alkynyl groups, have been synthesized and structurally characterized.
A New Hydrogen-Bonding Motif with Constituents Bearing Donor and Acceptor Sites 7 Å Apart
Authors: Heinze Katja , Reinhart Anja
Published: August 2018

Aryl substituted dipyrromethanes [di(pyrrol-2-yl)-phenyl-methanes] with hydrogen acceptor substituents R in para position of the aryl ring [R = CO2Me, CO2H, CONH(iPr) and NH2] located 7 Å apart from the hydrogen donor pyrrole nitrogen atom are shown to self-assemble in the solid state via hydrogen bonds to form rings or chains.
An Efficient One-Pot Conversion of THP- and TMS Ethers to Sulfonate Esters Using FeCl3-Montmorillonite K-10 Clay
Authors: Movassagh Barahman , Shokri Salman
Published: August 2018

Various tetrahydropyranyl and trimethylsilyl ethers are efficiently transformed into the corresponding sulfonate esters with sulfonyl chlorides in the presence of FeCl3-Montmorillonite K-10 clay.
A New Imidazole Alkaloid and Other Constituents from Pilocarpus grandiflorus and their Antifungal Activity
Authors: de Souza Rejane C. , Fernandes João B. , Vieira Paulo C. , da Silva M. Fátima das G. F. , Godoy Marizete F. P. , Pagnocca Fernando C. , Bueno Odair C. , Hebling M. José A. , Pirani José R.
Published: August 2018

The stems of Pilocarpus grandiflorus have afforded the new imidazole alkaloid 4,6-dehydro- 1,2,4,5-tetrahydro-2,5-dioxopilocarpine in addition to the 17 known compounds germanicol, β - amiryn, ocotillone, stigmast-4-en-3-one, 3β -hydroxy-stigmast-5-en-7-one, 6β -hydroxy-stigmast-4- en-3-one, β -sitosterol, scopoletin, 3-(1’,1’-dimethylallyl)-scopoletin, elisin, dictamine, 4-methoxy-2- quinolone, platydesmine, syringaresinol, syringaldehyde, syringic acid and vanillic acid. Their structures were elucidated on the basis of chemical and spectroscopic evidence. The phenolic compounds vanillic acid and syringaldehyde and the furoquinoline alkaloid platydesmine exhibited antifungal activity against Leucoagaricus gongylophorus, the symbiotic fungus of leaf-cutting ants (Atta sexdens rubropilosa).
Facile Deoxygenation of Hydroxylated Flavonoids by Palladium-Catalysed Reduction of its Triflate Derivatives
Authors: Kövér József , Antus Sándor
Published: August 2018

An efficient procedure to deoxygenate hydroxy substituted flavonoids, isoflavonoids and related compounds via their trifluoromethanesulfonates is presented. Their reduction with formic acid in the presence of a catalytic amount of palladium acetate, triethylamine and 1,3-bis(diphenylphosphanyl) propane (dppp) in DMF results in their des-hydroxy derivatives without affecting other functional groups.
Alternative Method for the Preparation of Ni(dddt)(edt) (dddt = 5,6-Dihydro- 1,4-dithiin-2,3-dithiolate, edt = cis-1,2- Ethylenedithiolate) and Similar Complexes
Authors: Papavassiliou G. C. , Anyfantis G. C.
Published: August 2018

Starting from 4,5-(ethylenedithio)-1,3-dithiol-2-one and 1,3-dithiol-2-one the disodium 5,6-dihydro-1,4-dithiin-2,3- dithiolate (Na2dddt) and disodium 1,2-dithiolate (Na2edt) salts were prepared, which react with NiCl2 in air to give the complex Ni(dddt)(edt) (3ab). This compound was characterized analytically and spectroscopically. The method is applicable for the preparation of similar unsymmetrical complexes.
Trifluoromethylaryl-Substituted Quinoxalines: Unusual Ruthenium- Amidininate Complexes and their Suitability for Anellation Reactions
Authors: Schramm Frank , Walther Dirk , Görls Helmar , Käpplinger Christian , Beckert Rainer
Published: August 2018

The reaction of the 2,3-dianilino-quinoxaline 1 with an equivalent of triethyl orthoformiate results in a cyclic aminalester 2. An excess of triethyl orthoformate results in the carbene dimer 4. With the help of boron trifluoride, 2 can be transformed into the imidazolium salt 3. Reaction of 1 with KOtC4H9 leads to a quinoxaline derivative 5 under anellation of a benzene ring whereas the related pyrazino-quinoxaline 6 (formed from tetraaminobenzene tetrahydrochloride and bis-(3- trifluoromethylphenyl) oxalimidoyl chloride) does not react under similar conditions. However, 6 can be activated towards anellation by employing the complex fragment [(tbbpy)2Ru]2+, tbbpy: bis(4,4’-di-tert-butyl-2,2’-bipyridine). This generates an unusual ruthenium complex 9 which could be characterised by X-ray diffraction. Complex 9 contains a pentacene derivative and coordinates the ruthenium fragment at the amidinate moiety thus forming a four-membered chelate ring. Isolation of a second ruthenium complex 8 which contains an intact pyrazino-quinoxaline 6 in which the metal is also coordinated to an amidinato group supports the assumption that the anellation reaction occurs only after metal complexation at the amidinate group. In contrast to this, the smaller [(tmeda)2Pd]2+ fragment reacts with the pyrazino-quinoxaline 6 to form the mononuclear Pd complex 10. Its structural motif (X-ray diffraction) shows that the palladium centre coordinates at the 1,4-diamino group of the intact pyrazino-quinoxaline to form a five-membered chelate ring. This suggests that the bulkiness of the complex fragment determines whether or not an anellation reaction can take place.
Structure Elucidation of 2-Amino-5-phenyl-2-oxazolin-4-one (Pemoline) and X-Ray Structure of its Hydrolysis Product 5-Phenyl-oxazolidine-2,4- dione
Authors: Kuś Piotr , Jones Peter G. , Celiński Rafał
Published: August 2018

In this study we compare spectroscopic properties of pemoline (2-amino-5-phenyl-2-oxazolin- 4-one) and its acid hydrolysis product 5-phenyl-oxazolidine-2,4-dione. Crystallization of pemoline from aqueous acetic acid gave single crystals of compound 2, the structure of which was determined by X-ray studies. All four crystallographically independent molecules form dimers linked by N-H···O = C hydrogen bonds.
NMR Studies on Alioline – A Novel Vinca Alkaloid
Authors: Habib-ur-Rehman  , Atta-ur-Rahman
Published: August 2018

Extensive NMR studies on the novel vinca alkaloid alioline (1) have been carried out. These studies include 1D NMR experiments, i.e. 1H-1H decoupling, NOED, 13C NMR (broad-band and DEPT) as well as 2D homonuclear (COSY, NOESY and J-resolved) and 2D-hetero COSY experiments.
Two Variations of Solvent-Reduced Wittig Olefination Reactions – Comparison of Solventless Wittig Reactions to Wittig Reactions under Ultrasonication with Minimal Work-up [1]
Authors: Watanabe Masataka , Morais Goreti Ribeiro , Mataka Shuntaro , Ideta Keiko , Thiemann Thies
Published: August 2018

Stabilized and semi-stabilized phosphoranes can be subjected to solventless Wittig reactions with carbaldehydes. Simple heating of a mixture of added components at 100 °C in an electric oven gives the corresponding olefins in good yield. Alternatively, the Wittig reactions can be carried out in a biphasic medium under ultrasonication. In this case, the Wittig products can be isolated by simple evaporation of the organic phase without additional work-up.
Silver(I)-Saccharinato Complexes with 2-(Aminomethyl)pyridine and 2-(2-Aminoethyl)pyridine Ligands: [Ag(sac)(ampy)] and [Ag2(sac)2(μ-aepy)2]
Authors: Hamamci Sevim , Yilmaz Veysel T. , Harrison William T. A.
Published: August 2018

Two new saccharinato-silver(I) (sac) complexes, [Ag(sac)(ampy)] (1), and [Ag2(sac)2(μ-aepy)2] (2), [ampy = 2-(aminomethyl)pyridine, aepy = 2-(2-aminoethyl)pyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and triclinic space group P1̄, respectively. The silver(I) ions in both complexes 1 and 2 exhibit a distorted T-shaped AgN3 coordination geometry. 1 consists of individual molecules connected into chains by N-H···O hydrogen bonds. There are two crystallographically distinct dimers in the unit cell of 2 and in each dimer, the aepy ligands act as a bridge between two silver(I) centers, resulting in short argentophilic contacts [Ag1···Ag1 = 3.0199(4) Å and Ag2···Ag2 = 2.9894(4) Å ]. Symmetry equivalent dimers of 2 are connected by N-H···O hydrogen bonds into chains, which are further linked by aromatic π(py)···π(py) stacking interactions into sheets.
Structure, Chemical Bonding and 119Sn Mössbauer Spectroscopy of LaRhSn and CeRhSn
Authors: Schmidt Tobias , Johrendt Dirk , Sebastian C. Peter , Pöttgen Rainer , Łątka Kazimierz , Kmieć Roman
Published: August 2018

The rare earth (RE) stannides LaRhSn and CeRhSn were prepared from the elements by arcmelting or by reactions in sealed tantalum tubes in a high-frequency furnace. The structures have been refined from X-ray single crystal diffractometer data: ZrNiAl type, P6̅2̅m, a = 748.74(5), c = 422.16(3) pm, wR2 = 0.0307, 310 F2 values for LaRhSn and a = 745.8(1), c = 408.62(9) pm, wR2 = 0.0397, 354 F2 values for CeRhSn with 14 variables per refinement. The structures contain two crystallographically different rhodium sites which both have a tricapped trigonal prismatic coordination: [Rh1Sn3RE6] and [Rh2Sn6RE3]. Together the rhodium and tin atoms (280 - 288 pm Rh-Sn distances in LaRhSn and 277 - 285 pm in CeRhSn) build up three-dimensional [RhSn] networks in which the rare earth atoms fill distorted hexagonal channels. DFT band structure calculations reveal a large cerium 4 f contribution at the Fermi level and a strong mixing of cerium 5d/4 f with rhodium 4d orbitals. These results are in agreement with the short Ce-Rh bonds (304 and 309 pm) and also with the electronic and magnetic properties. 119Sn Mössbauer spectra of LaRhSn and CeRhSn show a single tin site at isomer shifts of δ = 1.98(2) (LaRhSn) and 1.79(1) mm/s (CeRhSn) subject to quadrupole splitting of Δ EQ = 0.79(4) (LaRhSn) and 1.12(3) mm/s (CeRhSn). The 1.8 K data show no transferred hyperfine field at the tin site for CeRhSn.
Phenolic Glycosides from Symplocos racemosa
Authors: Ahmad Viqar U. , Zubair Muhammad , Abbasi Muhammad A. , Kousar Farzana , Ullah Farman , Fatima Naheed , Choudhary Muhammad. I.
Published: August 2018

The re-investigation of the chemical constituents of the bark of the stem of Symplocos racemosa Roxb. led to the isolation of two new phenolic glycosides, Symconoside A (1) and Symconoside B (2). The structures of the new compounds were determined by 1D and 2D-homonuclear and heteronuclear NMR spectroscopy, chemical evidences, and by comparison with the published data of the closely related compounds. The phenolic glycosides 1 and 2 displayed in vitro inhibitory activity against phosphodiesterase-I with the IC50 values of 158±0.02 and 900±0.08 μM, respectively.
Syntheses, Crystal Structures and Magnetic Properties of Rb2RuO4 and K2RuO4
Authors: Fischer Dieter , Hoppe Rudolf , Mogare Kailash M. , Jansen Martin
Published: August 2018

Potassium and rubidium oxoruthenates, A2RuO4, were synthesized from the alkali peroxides/ hyperoxides and ruthenium dioxide. Both compounds crystallize in the orthorhombic space group Pnma (no. 62), (K2RuO4: a = 7.673(2), b = 6.153(2) and c = 10.564(3)Å , Z = 4, 796 unique reflections, R=3.5%; Rb2RuO4: a =8.106(2), b = 6.270(1) and c =11.039(2)Å , Z =4, 889 unique reflections, R = 3.6%). The crystal structures, as determined from single crystal data, are of the β - K2SO4 type. Magnetic measurements reveal that both compounds are paramagnetic down to temperatures of around 60 K and further exhibit antiferromagnetic transitions, at around TN = 9 K for Rb2RuO4, and two transitions with TN = 14 K and 4 K for K2RuO4. The magnetic moments as determined applying Curie-Weiss law for both compounds are 2.68 μB, thus confirming the oxidation state +6 of ruthenium.
Potentiometeric Study of Binary Complexes of Triethylenetetraminehexaacetic Acid with Cd2+, Co2+, and Pb2+ Ions in Aqueous Solutions
Authors: Joshaghani Mohammad , Gholivand Mohammad Bagher , Mosavat Alireza
Published: August 2018

The interaction between triethylenetetraminehexaacetic acid, TTHA, and three divalent metal ions Cd(II), Co(II) and Pb(II) was investigated potentiometrically in two 1 : 1 and 2 : 1 metal to ligand mole ratio systems. The overall equilibrium formation constants were computed by the BEST program. The species distribution diagrams were also depicted using the SPE program. Eight protonation constants were obtained which were assigned for the protonation of nitrogen donors at first and carboxylic groups in continuation. For the 1 : 1 metal to ligand ratio, the main species in the middle pH region is MLH, the concentration of which decreases slowly on going to the basic region. The main complex at basic pH is ML, which becomes the sole species at pH above 10. In the 2 : 1 system, only the M2L species remain intact in a broad range from pH = 4 to the basic region. Compared to EDTA, TTHA has a higher relative stability with cadmium and so, can potentially present as a suitable candidate for chelation therapy
Synthesis of Iso-C-nucleoside Analogues from 1-(Methyl 2-O-benzyl-4,6- O-benzylidene-3-deoxy-α-D-altropyranosid-3-yl)but-3-yn-2-ones
Authors: Otero Iran , Feist Holger , Michalik Dirk , Michalik Manfred , Quincoces José , Peseke Klaus
Published: August 2018

1-(Methyl 2-O-benzyl-4,6-O-benzylidene-3-deoxy-α-D-altropyranosid-3-yl)but-3-yn-2-one (3a) reacted with 3-amino-1H-1,2,4-triazole and 5-aminopyrazole-4-carboxylic acid derivatives in the presence of base to furnish the triazolo[1,5-a]pyrimidine (5) and the pyrazolo[1,5- a]pyrimidines (8a - d), respectively. Treatment of 1-(methyl 2-O-benzyl-4,6-O-benzylidene-3- deoxy-α-D-altropyranosid-3-yl)-4-phenyl-but-3-yn-2-one (3b) with cyanacetamide, 2-cyano-N- (4-methoxyphenyl)acetamide und N-aryl-3-oxo-butyramides afforded the substituted nicotinonitriles (11a - d). Furthermore, reaction of 3b with 2-benzimidazolyl-acetonitrile yielded the benz[4,5]imidazo[1,2-a]pyridine-4-carbonitrile (13). Deprotection of 8d in two steps afforded the 2-amino-N-benzyl-5-(methyl 3-deoxy-α-D-altropyranosid-3-yl-methyl)pyrazolo[1,5-a]pyrimidine- 3-carboxamide (10). Compounds 5 and 11d were treated with AcOH/H2O to furnish the 5-(methyl 2-O-benzyl-3-deoxy-α-D-altropyranosid-3-yl-methyl)[1,2,4]triazolo[1,5-a]pyrimidine (6) and the 3-acetyl-1,2-dihydro-1-(4-methoxyphenyl)-6-(methyl 2-O-benzyl-3-deoxy-α-D-altropyranosid-3-ylmethyl)- 4-phenylpyridin-2-one (12), respectively.
Oxokohlenstoffe und verwandte Verbindungen, 31 [1]. 3-Antipyryl-4-hydroxy-cyclobutendion (Antipyrylsemiquadratsäure) und seine Derivate / Oxocarbons and Related Compounds, 31 [1]. 3-Antipyryl-4-hydroxy-cyclobutenedione (Antipyrylsemisquaric Acid) and its Derivatives
Authors: Schmidt Arthur H. , Kohler Jochen , Pretsch Ramona , Freytag-Loringhoven Sarah von , Wiesert Peter R.
Published: August 2018

Antipyrylsemisquaric chloride (9) has been prepared with excellent yield from antipyrylsemisquaric acid (8) and oxalic dichloride in the presence of dimethylformamide. Reaction of 9 with N and S nucleophiles afforded antipyrylsemisquaric acid derivatives, such as amides 12a - t, 14a - e, 15, hydrazides 18a - e, and thioesters 21a - i.
Sigmoiside F and Propyloxyamyrin, Two New Triterpenoid Derivatives from Erythrina sigmoidea (Fabaceae)
Authors: Kouam Jacques , Meli Alain L. , Choudhary Muhammad I. , Fomum Zacharias T.
Published: August 2018

A new triterpenoid saponin, olean-12-ene-3β ,19β ,24-triol-3-O-β -D-glucopyranoside, named sigmoiside F and a new triterpenoid, 3β -n-propyloxy-β -amyrin, were isolated from the methanolic extract of the stem bark of Erythrina sigmoidea. Their structures were characterized by chemical and spectral analysis.
Hydrazine Adducts of Tri(tert-butyl)aluminum, -gallium and -indium – a Systematic Approach
Authors: Uhl Werner , Abel Thomas , Kösters Jutta , Rogel Friedhelm
Published: August 2018

Treatment of the monomeric trialkylelement compounds Al(CMe3)3, Ga(CMe3)3, and In(CMe3)3 with different hydrazines H2N-N(H)R (R=Me, CMe3, C6H5) yielded the corresponding adducts (Me3C)3E ← NH2-N(H)R, 1 to 9, in almost quantitative yields. All products were characterized by crystal structure determinations and shown to have the NH2 group of the hydrazine ligands attached to the central Group 13 atom. These adducts are excellent starting compounds for the generation of hydrazides by thermolysis with release of butane
Eremophilanolides from Roldana lobata
Authors: Maldonado Jhon , Arciniegas Amira , Pérez-Castorena Ana-L. , Arciniegas Mónica , Villasenor José Luis
Published: August 2018

Three new eremophilanolides (1 - 3) and several known compounds were isolated from Roldana lobata. The structures of the new compounds were elucidated by spectroscopic methods. The cytotoxicity of the isolated compounds was tested against selected cancer cell lines.
N–O Bond Cleavage During the Deprotonation of N,O-Bis(trimethylsilyl)hydroxylamine
Authors: Venugopal Ajay , Willner Alexander , Mitzel Norbert W.
Published: August 2018

The reaction of N,O-bis(trimethylsilyl)hydroxylamine with potassium hydride in pentane affords a product of the formula {K6[OSiMe3]4[ON(SiMe3)2]2}, resulting from deprotonation followed by N-O bond cleavage and 1,2-silylshift. The compound was characterised by elemental analysis and by single crystal X-ray diffraction. The aggregate consists of a K3O3 bis-cubane core, with N(SiMe3)2 groups at the oxygen atoms shared by the two cubes, andMe3Si groups attached to the four O vertices. Two weak K···N interactions are also detected in the solid state structure.
The Crystal Structure of trans-[{Rh(μ-Cl)(CO)(coe)}2 ] (coe = cis-cyclooctene)
Authors: Böttcher Hans-Christian , Mayer Peter
Published: August 2018

Single crystals of trans-[{Rh(μ-Cl)(CO)(coe)}2] (1) obtained from the reaction of [{Rh(μ-Cl)(coe)2}2] (coe = cis-cyclooctene) with carbon monoxide have been analyzed by X-ray crystallography (monoclinic, C2/c, Z = 4, a = 15.6271(4), b = 13.6943(4), c = 10.4169(2) Å ; β = 115.3549(17)°; V = 2014.50(9) Å3; T = 200(2) K).
Synthesis of Dimethyl 1-(Hetero)aryl-4-oxo-1,4-dihydropyridazine- 3,5-dicarboxylates from Dimethyl 3-Oxopentane-1,5-dioates
Authors: Pahovnik David , Uršič Uroš , Grošelj Uroš , Meden Anton , Svete Jurij , Stanovnik Branko
Published: August 2018

Dimethyl 3-oxopentane-1,5-dioate (dimethyl acetone-1,3-dicarboxylate) (1) was transformed first with (hetero)arenediazonium salts 3a - j into dimethyl 2-[(hetero)arylhydrazono]pentane-1,5-dioates 4a - j followed by reaction with N,N-dimethylformamide dimethylacetal (DMFDMA) to afford, without isolation of intermediates 5a - j, dimethyl 1-(hetero)aryl-4-oxo-1,4-dihydropyridazine-3,5- dicarboxylates 6a - j. An alternative method represents transformation of 1 with DMFDMA into dimethyl 2-[(dimethylamino)methylidene]-3-oxopentane-1,5-dioate (7) followed by treatment with (hetero)arenediazonium salts 3a - c, j to give pyridazine derivatives 6a - c,j.
A Polyoxometalate-templated Inorganic-Organic Hybrid Compound Containing a Crown-like Metallamacrocyclic Cation [Ag6(1,2,4-triazole)6]6+
Authors: Chen Xiang-Min , Wang De-Song , Luo Qing-Zhi , Wang Ran
Published: August 2018

A new polyoxometalate(POM)-templated inorganic-organic hybrid compound, [Ag6(trz)6]- [PMo12O40]2 ・ 6H2O (1) (trz = 1,2,4-triazole) has been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, thermogravimetric analysis and cyclic voltammetry. In compound 1, six Ag+ ions are linked by six trz molecules to give a hexanuclear [Ag6(trz)6]6+ cycle. The six trz molecules are not co-planar, but adopt a crown-like shape. Cavities, with sizes of about 7.706×7.706 Å2, are found with the hexanuclear cycles packed along the c axis. The Keggin anions, as templates, are inserted in the 3D supramolecular framework. The electrochemical and electrocatalytic behavior of 1 has been studied in detail. The results exhibit that the redox ability of the Keggin anions can be maintained in the hybrid solid which has good electrocatalytic activity toward the reduction of bromate, hydrogen peroxide and nitrite.
Preparation and Characterization of Macrocyclic Dinickel Complexes Coligated by Tetrazolate Ligands
Authors: Lozan Vasile , Voitekhovich Sergei V. , Gaponik Pavel N. , Ivashkevich Oleg A. , Kersting Berthold
Published: August 2018

The dinuclear nickel(II) complex [Ni2LCl]+ (1), where (L)2− represents a 24-membered macrocyclic hexamine-dithiophenolate ligand, reacts readily with 5-R-tetrazolate ligands to give the complexes [Ni2L(RCN4)]+, where R = H (2), Me (3), Ph (4). The new complexes were either isolated as perchlorate or tetraphenylborate salts and fully characterized by elemental analysis, UV/Vis, and IR spectroscopy. The structures of 2[BPh4] · MeCN, 3[BPh4] · 2MeCN, and 4[BPh4] ·MeCN were determined by X-ray crystallography, showing that all tetrazolate units are in a 2,3-bridging mode to generate dioctahedral N3Ni(μ-S)2(μ-N4CR)NiN3 core structures. The RCN4
− groups interact less strongly with the [Ni2L]2+ fragment than pyrazolate ligands (CH)3N2
− as reflected in the longer Ni-N distances.
Donor/Acceptor Interaction-assisted Mesophase Formation in Liquid Crystals Containing Azobenzenes and Their Polymers
Authors: Saravanan Chinnusamy , Deepa Mohan , Kannan Palaninathan , Senthil Sengodan
Published: August 2018

Azobenzene-based monomers and their polymers containing donor or acceptor groups at terminal positions have been synthesized. The liquid crystalline (LC) mesophase stability of one type of polymer and mixtures of donor or acceptor substituted polymers have been investigated. Mesophase formation and stability of the mixtures were studied using differential scanning calorimetry (DSC) and a hot-stage optical polarizing microscope (HOPM). The mesophase stability of the mixtures was better than those of the individual components. Binary mixture studies of acceptor monomers (a) and donor monomers (d) show that the pure low molecular weight compounds did not form any molecular aggregates and failed to show LC properties, whereas the mixture of donor substituted azobenzene and acceptor substituted azobenzene exhibits LC property. In the case of polymers, the individual acceptors (A) or donors (D) exhibit LC property, and their mixture stabilizes the crystallinity of the mesophase. The results of correlation studies of various proportions of mixtures of a/d and A/D with regard to LC properties and their mesophase stabilities are presented
Tin-doped MgTiO3: A New Material for Studying the Solid-Gas Interface Making Use of the 119Sn Mössbauer Spectroscopic Probe
Authors: Fabritchnyi Pavel B. , Afanasov Mikhail I. , Korolenko Mikhail V.
Published: August 2018

A co-precipitated hydroxide precursor containing equimolar quantities of Mg2+ and Ti4+, doped by impregnation with ca. 0.1 at-% Sn4+, after annealing in flowing H2 at 600 °C, yields MgTiO3 microcrystals containing Sn2+ ions. As attested by in situ 119Sn Mössbauer spectroscopic measurements (at 295 K, isomer shift δ = 2.80±0.01 mms−1 and quadrupole splitting Δ = 1.80±0.02 mms−1) the Sn2+ ions possess a low coordination number (CN < 6) and exhibit anomalously high resistance to be transformed to metallic β -Sn. Upon contact with air, at r. t., fast oxidation of Sn2+ to Sn4+ (δ = 0.03±0.01 mms−1 and Δ ≤ 0.3 mms−1) occurs. Quite a similar behavior was previously observed for the tin dopant located on the surface of Cr2O3, α-Al2O3 or MgO crystallites. Independent evidence for the presence of tin on surface sites of the MgTiO3 substrate also is provided by XPS measurements. Whereas the Sn2+ Mössbauer spectrometric parameters are virtually unaffected upon further annealing in H2 at higher temperature (900 °C), this treatment prevents the tin from reacting with ambient O2. Such a passivation effect is imputed to itinerant t2g electrons which inactivate absorbed oxygen. The high-temperature annealing is also responsible for the appearance of a minor single-line spectral component with δ = 1.6±0.1 mms−1. This isomer shift value cannot be attributed to any known compound of tin that could be formed under the experimental conditions used. The puzzling spectral component is accounted for by the presence of residual Sn4+ ions immobilizing itinerant t2g electrons on one of the neighboring Ti4+ cations in the bulk of the MgTiO3 crystallites.
Determination of the Viscosity of the Ionic Liquids [bmim][PF6] and [bmim][TF2N] Under High CO2 Gas Pressure Using Sapphire NMR Tubes
Authors: Dyson Paul J. , Laurenczy Gábor
Published: August 2018

The viscosities of the ionic liquids [bmim][PF6] and [bmim][TF2N] (bmim = 1-methyl-3- butylimidazolium, TF2N = bis(trifluoromethylsulfonyl)imide) have been determined under CO2 pressure at 298 K. The viscosity decreases from 381 to 23 cP for [bmim][PF6] without CO2 and for 2.17 molal CO2 solutions (mole fraction XCO₂ = 0.381, 55 bar CO2), respectively. For [bmim][TF2N] the viscosity decreases from 54 cP for the ionic liquid to 21 cP for a 1.61 molal solution of CO2 (mole fraction XCO₂ = 0.403, 55 bar CO2).
Different Cerium Valence Transitions Observed by Hydrogenation of the Ternary Germanides CeRhGe and CeIrGe – Structure, Physical Properties and Chemical Bonding
Authors: Chevalier Bernard , Gaudin Etienne , Al Alam Adel F. , Matar Samir F. , Weill François , Heying Birgit , Pöttgen Rainer
Published: August 2018

The ternary germanides CeRhGe and CeIrGe which crystallize in the orthorhombic TiNiSi-type structure, absorb hydrogen at 523 K. X-Ray powder diffraction and transmission electron microscopy indicate that the hydrides CeRhGeH1.8 and CeIrGeH1.8 adopt the hexagonal ZrBeSi-type structure. Magnetization, electrical resistivity and thermoelectric power measurements reveal that these hydrides are intermediate-valence compounds. An unusual transition from antiferromagnetic to spin fluctuation behavior occurs upon hydrogenation of CeRhGe, while on the contrary, CeIrGeH1.8 presents a Kondo temperature of 285 K smaller than that observed for CeIrGe (610 K). In order to explain these opposite valence transitions, the electronic structures of the hydrides have been selfconsistently calculated within the local spin density functional theory (LSDF). The structures are compared to those reported previously by us for CeRhGe and CeIrGe.
Synthesis, Crystal Structure and Characterization of a 1D Polyoxometalate-based Compound: {[Pr(H2O)7][CrMo6H6O24]} · 4H2O
Authors: Zhao Lijie , Shen Shuchang , Yu Haiming
Published: August 2018

A novel polyoxometalated-based compound, {[Pr(H2O)7][CrMo6H6O24]} · 4H2O, was prepared and characterized by elemental analysis, infrared and ultraviolet spectroscopy, TG measurement and single crystal X-ray diffraction. A chain-like coordination polymer is formed from a heteropolyanion [CrMo6H6O24]3− as a building unit and [Pr(H2O)7]3+ cations as linker. The chains are linked into an extensive three-dimensional supramolecular network through hydrogen bonding. The synthesis of 1 is accomplished only from pre-synthesized Anderson clusters, but not from simple starting materials.
Copper(II), Nickel(II), Cobalt(II), and Chromium(III) Complexes Based on 6,6′-Bis{[methyl(oxido)imino]methyl}-2,2′-bipyridine
Authors: Petkova Elena G. , Lampeka Rostislav D. , Gorichko Marian V. , Palamarchuk Gennadiy , Dyakonenko Viktoriya V. , Zubatyuk Roman I. , Shishkin Oleg V.
Published: August 2018

The bipyridine-based ligand 6,6'-bis{[methyl(oxido)imino]methyl}-2,2' -bipyridine (L) reacts with copper(II) chloride in methanol to produce a tetrachlorocuprate(II) salt [CuL][CuCl4] (1). Reactions of equimolar quantities of Ni(NO3)2 · 6H2O and Co(NO3)2 · 6H2O with L in methanol produce compounds [ML(NO3)2] (M = Ni (2), M = Co (3). Reaction of Cr(NO3)3 · 6H2O with L affords [Cr(L)(H2O)2](NO3)3 · 0.5H2O (4). The structures of compounds 1 - 4 were determined by X-ray diffraction. In all four complexes L exhibits the tetradentae chelating mode of coordination.
Synthesis of Cobalt(III), Iron(III), and Chromium(III) Complexes with Salicylaldiminato Ligands: Evaluation of the Complexes as Catalysts for Oxidation of L-Cysteine
Authors: Abu-Surrah Adnan S. , Abdel-Halim Hamzeh M. , Al-Qaisi Feda’a M.
Published: August 2018

A series of new cobalt(III)-, iron(III)-, and chromium(III)-based complexes of the general formula [M(N∩O)2Cl] (N∩O: N-salicylidene(X)amine and sodium N-(4-sulfonatosalicylidene(X)amine)) (X = cyclohexyl and 1-naphthyl) was prepared and characterized. Some of the isolated complexes have been evaluated as catalysts for the oxidation of L-cysteine. Preliminary results show that the rate of oxidation of L-cysteine is influenced by the nature of the metal center, the geometry of the complex, the auxiliary substituents, and the backbone of the ligand.
Synthesis and Crystal Structure of a Polynuclear Copper-selenide Cluster [CuI
36(CuIICl)2Se13(SePh)12(dppe)6] · 3EtOH
Authors: Duan Taike , Zhang Xiu-Zheng , Zhang Qian-Feng
Published: August 2018

Treatment of copper(I) chloride in the presence of the bidentate phosphine ligand Ph2PCH2CH2- PPh2 (dppe) with Se(SiMe3)2 and PhSeSiMe3 in THF solution afforded a novel polynuclear mixedvalence copper-selenide cluster compound [CuI
36(CuIICl)2Se13(SePh)12(dppe)6] · 3EtOH. A central μ8-Se atom is surrounded by 14 copper atoms, 2 of which are trigonal-bipyramidally coordinated with terminal Cu-Cl bonds and are thus defined to be copper(II) centers. The 14 copper atoms are also enclosed by another distorted Se12 icosahedron to form a [Se13Cu14] central unit in the cluster. The cluster unit core is further extended to the periphery by coordination of the Se12 substructure to another 24 copper atoms, 12 of which are ligated by the six dppe ligands.
Synthesis, Solution Behavior, Molecular and Supramolecular Structures of the Water-soluble Gold(I) Saccharinate Complexes M[Au(Sac)2] (M = Na, K, NH4)
Authors: Cinellu Maria Agostina , Maiore Laura , Schier Annette , Schmidbaur Hubert , Rossi Davide
Published: August 2018

Three gold(I) saccharinate complexes of the type M[Au(Sac)2] (M = Na, K and NH4) have been prepared by treatment of Au(tht)Cl (tht = tetrahydrothiophene) with saccharine and MOH in MeOHacetone. The compounds are very stable in the solid state but moderately soluble and of limited stability in water. Single crystal X-ray diffraction analysis of the three compounds revealed a linear coordination of the gold atom by the two N-bonded saccharinato ligands. For M = Na, the two heterobicyclic ligands are roughly coplanar with a cis orientation of the two carbonyl groups which allows for a chelation of the sodium cation. For M = K, NH4, the ligands form large dihedral angles with a trans orientation of the donor sites out of which the potassium cations are coordinated in bridging positions between neighboring anions, and the ammonium ions are hydrogen-bonded, respectively.
Structure and Chemical Bonding of PrRuSn
Authors: Riecken Jan F. , Alam Adel F. Al , Chevalier Bernard , Matar Samir F. , Pöttgen Rainer
Published: August 2018

The new ternary stannide PrRuSn was synthesized from the elements via arc-melting. PrRuSn is isopointal to the orthorhombic TiNiSi-type structure, space group Pnma. The structure was characterized by X-ray powder and single crystal diffraction: a = 761.7(2), b = 483.9(2) and c = 730.3(3) pm, wR2 = 0.0386, 433 F2 values, 20 variables. The ruthenium and tin atoms in PrRuSn build up a three-dimensional [RuSn] polyanionic network with Ru-Sn distances in the range 268 - 274 pm. The praseodymium atoms fill channels within the polyanion. They bind to the network via short Pr-Ru distances of 301 and 302 pm. Electronic structure calculations on PrRuSn and isopointal PrPdSn underline these features and reveal strong T-Sn (T = Ru, Pd) interactions within both solid state structures.
cis/trans Isomers of Dimeric Dialkylaluminum and Dialkylgallium Hydrazides
Authors: Uhl Werner , Vogelpohl Andreas
Published: August 2018

The reaction of diethylaluminum hydride with the hydrazine derivatives 1-aminopyrrole and 1- aminopiperidine afforded the corresponding dialkylaluminum hydrazides (1 and 2) by the release of elemental hydrogen. Both products are dimeric in the solid state. While 1 adopts a cis arrangement of the pyrrole groups, a trans configuration was determined for the piperidine compound 2. Only 1 gives an equilibrium mixture of cis and trans isomers in solution. Similar compounds (3 and 4) were obtained by the treatment of the same hydrazines with di(tert-butyl)gallium hydride. Both products exhibit the trans configuration in the solid state, but interestingly only the piperidine derivative 4 shows a cis/trans equilibrium in solution.
On the Photocatalytic Performance of Indium Tantalate and its Modifications
Authors: Douiheche Maoiheb , Haberkorn Robert , Beck Horst P
Published: August 2018

The photocatalytic activity of InTaO4 has been studied regarding the effect of a substitution of In by Ni, of the performance of NiO as well as Ag2O as co-catalysts, and especially of the products of different methods of preparation (solid state reaction and/or sol-gel process) and their particle sizes. Solid state reactions and sol-gel procedures were used to synthesise different products for the catalytic reaction in a reactor vessel equipped with amercury UV lamp. The optical properties and the band gap values of the different products were evaluated by reflectance spectroscopy, and the microstructure parameters of the crystalline products were determined by an elaborate profile analysis of the X-ray diagrams. The evolution of H2 and O2 under irradiation was quantified by a GC setup. The causes for the deviations of the performance of these catalysts from the values reported elsewhere are discussed.
Self-assembly Through Non-coordinating Intermolecular Forces, Part 2 [1]. Synthesis, Crystal Structure and Packing of [Cu2(μ-phthalazine)3(phthalazine)2][CF3SO3]2
Authors: Plasseraud Laurent , Cattey Hélène , Richard Philippe
Published: August 2018

Treatment of the copper(I) trifluoromethanesulphonate toluene complex {[Cu(CF3SO3)]2 · C6H5Me} (1) with phthalazine (phtz, C8H6N2) in dichloromethane-acetonitrile solution yielded, via the bis(acetonitrile)tris(μ-phthalazine)dicopper(I) trifluoromethanesulphonate intermediate (2), the novel bis(phthalazine)tris(μ-phthalazine)dicopper(I) trifluoromethanesulphonate salt (3). Compound 3 was completely characterised and the molecular structure determined by single-crystal X-ray diffraction. Complex 3 crystallises in the monoclinic system, space group C2/c, with a = 26.9527(10), b = 10.9558(7), c = 19.2104(10) Å , β = 127.268(2)◦, V = 4514.3(4) Å3 and Z = 4. The copper(I) coordination geometry is tetrahedral, each copper centre being linked to four phthalazine molecules. Dicationic units of 3 which present an unusual paddle wheel-like shape constitute appropriate organometallic building blocks for the construction of a supramolecular solid-state architecture. The analysis of the packing of the molecules of 3 in the crystal revealed an unprecedented 2-dimensional network, resulting from intermolecular π-π and electrostatic interactions.