bluuebunny/crossref_metadata_2025 huggingface dataset:
Reactions in Molten Alkalimetal Polychalcogenides: What Happens in the Melt? A Study of the Reactions in the System K-Nb-S Using Differential Scanning Calorimetry, Infrared Spectroscopy, and X-Ray Powder Diffraction
Authors: Dürichen Peter , Bensch Wolfgang
Published: August 2018

The reactions of potassium polysulfides with elemental Nb were investigated with different analytical techniques. The amount of the polysulfide applied has no influence onto product formation, i. e. the ratio K2Sx: Nb is not important. The length of the polsysulfide chain, i. e. the value of x in K2Sx determines what product is formed. In sulfur-poor melts, K3NbS4 is observed. Increasing x to 5 - 6, K4Nb2S11 is formed with a structure containing S2
2− anions. Finally, applying a melt with x > 6, K6Nb4S25 is found as the product with a crystal structure containing the S5
2− polysulfide anion. When K2Sx (x < 5) is heated with sulfur in the first step the pentasulfide K2S5 is formed. Immediately after melting of K2S5 a reaction with elemental Nb occurs. The results of FT-IR and X-ray investigations have demonstrated that after oxidation the anion [Nb2S11]4− is formed relatively fast, and after a short time crystalline K4Nb2S11 can be detected. After 24 h the reaction is complete.
ortho-Lithiation of Benzene-1,2-dithiol: A Methodology for ortho-Functionalization of Benzene-1,2-dithiol
Authors: Huynh Han Vinh , Seidel Wolfram W. , Lügger Thomas , Fröhlich Roland , Wibbeling Birgit , Hahn F. Ekkehardt
Published: August 2018

The ortho-lithiation of benzene-1,2-dithiol with three equivalents of nBuLi afforded monoas well as di-C-lithiated intermediates. The surprising kinetically controlled formation of di- C-lithiated species offers the opportunity to obtain dimercaptobenzoic and -terephthalic acid derivatives in a onepot synthesis in reasonable yields. Both compounds are versatile building blocks for the synthesis of macrocycles containing arylenedithiol units. Focusing on novel terephthalic acid derivatives, two preparation routes, via amide and via alkyl linkage, respectively, have been elaborated. The reaction sequence (i) sulfur protection using either isopropyl or benzyl groups, (ii) transformation of the carboxylic function into an amide or an alkyl group and (iii) subsequent removal of the protection groups afforded the terephthaldiamidedithiol 6 and the 1,2-bis(2,3-dimercaptophenyl)ethane 11.
Dinuclear Derivatives of Mn2(CO)10 with the Ligand Tri(1-Cyclohepta- 2,4,6-Trienyl)Phosphane, P(C7H7)3, and their Oxidative Cleavage
Authors: Herberhold Max , Milius Wolfgang , Pfeifer Andreas
Published: August 2018

The photo-induced reaction of Mn2(CO)10 with the olefinic phosphane P(C7H7)3 (1; [P] if coordinated to a metal) leads stepwise to the axially substituted derivatives ax-{Mn2(CO)9[P]} (2) and ax,ax-{Mn2(CO)8[P]2} (3). Oxidative cleavage of 3 by halogens gives cis-{Mn(X)(CO)4[P]} (X = Cl (4a), Br (4b), I (4c)), whereas oxidation of 3 with NOBF4 provides a route to the salt {Mn(CO)4[P]}BF4 (5) which is also accessible by halide abstraction from 4b by AgBF4. The reactivity of the bromo complex 4b has been studied, and analogues such as cis-{Mn(R)(CO)4[P]} (R = Me (4d), Fc (4e) and N(iPr)2 (4f)) have been prepared. The displacement of a carbonyl ligand from 4b by iodide leads to mer-{Mn(I)(CO)3[P]} (6c) and by 1 to mer,trans-{Mn(Br)(CO)3[P]2} (7b). The complexes mer-{Mn(X)(CO)3[P]} (6a-c) are obtained by splitting the dimers, Mn2(CO)6(CH3CN)2- (μ −X)2 (X = Cl, Br, I), with P(C7H7)3 (1). The cation in 5 and the halogeno compounds 6a-c contain [P] (1) as a chelating four-electron ligand which uses one cyclohepta-2,4,6-trienyl substituent for π-complexation. The coordinated double bond in 6c can be displaced by phosphites P(OR)3 (R = Me, Et) to give fac-{Mn(I)(CO)3[P(C7H7)3][P(OR)3]} (8c). The structures of the new complexes 2-8 have been assigned on the basis of their carbonyl stretching absorption patterns in the IR spectra and by their NMR spectra (1H, 13C, 31P). Single-crystal X-ray structure analyses have been carried out for 3 and 6c.
Tungstenmethyl-Dimethylsilanols Cp(Oc)2(R3P)W—CH2—SiMe2OH (R = Me, Ph) – Synthesis Via Oxygenation or Hydrolysis
Authors: Hofmann Marco , Malisch Wolfgang , Hupfer Heike , Nieger Martin
Published: August 2018

The tungstenmethyl-dimethylsilanols Cp(OC)2(R3P)W-CH2-SiMe2OH [R = Me (6a), Ph (6b)] have been synthesized by oxofunctionalization of the tungstenmethyl-silanes Cp(OC)2(R3P)W- CH2-SiMe2H [R = Me (3a), Ph (3b)] with dimethyldioxirane. 6a has been additionally obtained by Et3N-assisted hydrolysis of the tungstenmethyl-chlorosilane Cp(OC)2(Me3P)W-CH2- SiMe2Cl (5). Compounds 6a,b are stable with respect to self-condensation, but controlled condensation of 6a with Me2Si(H)Cl in the presence of triethylamine has been realized to give the tungstenmethyl-substituted disiloxane Cp(OC)2(Me3P)W-CH2-SiMe2O-SiMe2H (7). The new compounds have been identified IR- and NMR-spectroscopically and, in the case of 3a, by X-ray analysis.
Metallkomplexe von Biologisch Wichtigen Liganden, CXLVIII [1]. Katalytische Peptidsynthese aus Glycinester miit Hilfe von Triflaten Und Cloriden der Seltenen Erden, sowie von Metall(III), (IV), (V) und (VI)-Chloriden / Metal Complexes of Biologically Important Ligands, CXLVIII [1]. Synthesis of Peptides from Glycine Ester Catalysed by Triflates and Chlorides of Metal(III, IV, V And VI) Ions
Authors: Schapp Jan , Beck Wolfgang
Published: August 2018

Formation of di- and triglycine ethylester which were determined by HPLC after derivatisation with dansyl chloride was observed in medium to high yields from CH2Cl2 solutions of glycine ethylester in the presence of metal triflates and metal chlorides: FeCl3 (yield 82%), AlCl3 (73%), GdCl3 (56%), La(OTf)3 (59%), Sc(OTf)3 (55%), ZrCl4 (62%), HfCl4 (60%), VOCl3 (43%), TaCl5 (29%). Esters of higher α-amino acid esters (AlaOMe, PheOMe) gave lower yields in peptide formation.
Metallkomplexe mit Biologisch Wichtigen Liganden, CIL [1]. Metallorganische η2-N,O-Lysinato-Komplexe / Metal Complexes Of Biologically Important Ligands, Cil [1]. Organometallic η2-N,O-Lysinato-Complexes
Authors: Ponikwar Walter , Beck Wolfgang
Published: August 2018

η2-N,O-Chelate complexes LnM[NH2CH(CO2)CH2CH2CH2CH2NH+
3 Cl-] with L-lysinate in the protected ω-ammonium form (LnM = (allyl)2Rh, (2-pyridylphenyl)2Ir, (p-cymene)(Cl)Ru, (C6Me6)(Cl)Ru, (C5Me5)(Cl)Rh, (C5Me5)(Cl)Ir) were obtained from chloro bridged complexes. A heterometallic lysinate bridged complex Cp*(Cl)IrNH2CH(CO2)(CH2)4NH2Ir(Cl)Cp* is formed with Cp*(Cl)Ir(N,O-lysinate·HCl) and [Cp*RhCl2]2.
Synthese monofluorierter cyclopropanoider Nucleosidanaloga / Synthesis of Monofluorinated Cyclopropanoic Nucleoside Analogues
Authors: Csuk René , Thiede Gisela
Published: August 2018

A novel class of cyclopropanoid monofluorinated nucleoside analogues was easily prepared starting from a suitable protected (fluorocyclopropyl)methanol derivative.
Hydroboration of Bis(Trimethylsilyl)Ethyne. New Aspects of Hydroboration
Authors: Wrackmeyer Bernd , Tok Oleg. L. , Milius Wolfgang , Bhatti Moazzam H. , Ali Saqib
Published: August 2018

The hydroboration of bis(trimethylsilyl)ethyne, Me3Si-C≡C-SiMe3 1, with 9-borabicyclo [3.3.1] nonane (9-BBN) gives first the expected (Z)-alkene 5 which rearranges, without UV irradiation, after several days quantitatively into the (E)-alkene 6. Heating of 6 in the presence of a further equivalent of 1 leads, again almost quantitatively, to an allene, the 1,1,4,4-tetrakis(trimethylsilyl)-4-[9-(9- borabicyclo[3.3.1]nonyl)]buta-1,2-diene 8. Reactive structures arising from π-σ delocalisation involving the boryl group are proposed to be responsible both for the cis/trans-isomerisation and the allene formation. It is suggested that analogous structures may explain the previously observed formation of allenes 9 and 10, tin-analogues of 8. The structures of 5, 6 and 8 in solution follow from a consistent set of NMR data (1H, 11B, 13C, 29Si NMR), and the solid-state structure of 8 was confirmed by X-ray analysis.
Synthesis and Structural Characterization of the Mixed Ligand Complex [Cu(Hml)2(Phen)] · 2 H2O (H2ml = 2-Methyllactic Acid)
Authors: Carballo Rosa , Covelo Berta , Vázquez-Lópeza Ezequiel M. , Castiñeiras Alfonso , Niclós Juan
Published: August 2018

A new mixed-ligand complex of copper(II) with 1,10-phenanthroline and 2-methyllactate was prepared. [Cu(HmL)2(phen)] ·2H2O (where HmL = monodeprotonated 2-methyllactic acid) was characterized by elemental analysis, IR, electronic and EPR spectroscopy, magnetic measurements at room temperature, thermogravimetric analysis and X-ray diffractometry. The copper atom is in a tetragonally distorted octahedral environment and the 2-methyllactato ligand is bidentately chelating. The presence of lattice water molecules mediates the formation of a three-dimensional network.
Preparation and Crystal Structure of Hexapotassium-μ-Oxo-Hexathiodititanate(IV), K6Ti2OS6
Authors: Klepp Kurt O. , Fabian Ferdinand
Published: August 2018

Pale yellow crystals of the title compound were obtained by reacting an intimate mixture of K2S, K2S2O4, Ti and S at 650 °C. K6Ti2OS6 is monoclinic, mP60, s. g. P21/c. It is characterized by the formation of bitetrahedral complex anions, [S3TiOTiS3]6−, which adopt a staggered conformation. The mean Ti-S and Ti-O bond lengths are 2.242(1) and 1.836(2) Å , respectively, the Ti-O-Ti bond angle is 153.8(2)°. Two K+ ions complete the coordination of the bridging oxygen atom by the cations to a heavily distorted tetrahedral configuration. The anions are arranged in corrugated slabs running parallel to (100). The packing and crystallographic relationship to K6Co2O7 are discussed.
(Phosphine)Silver(I) Sulfonate Complexes
Authors: Römbke Patric , Schier Annette , Schmidbaur Hubert
Published: August 2018

Phosphine)silver(I) organosulfonate complexes of the type (R3P)AgOS(O)2R’ have been prepared in good yields from the corresponding silver sulfonates and tertiary phosphines in dichloromethane solution [R3 = Ph3, Ph2(2-Py), Me2Ph, with R’ = 4-Me-C6H4; R = Ph, R’ = Et and 2,5-Me2-C6H4]. If ethanol is present in the reaction mixture, the products contain one equivalent of ethanol. The crystal structures of (Ph3P)AgOS(O)2(C6H4-4-Me)(EtOH) (1), and (Me2PhP)AgOS(O)2(C6H4-4- Me) (5) have been determined. Complex 1 is present as a dimer in which the monomeric units feature intermolecular Ag-O donor/acceptor bonding in a four-membered ring. The coordination sphere of the silver atoms is further complemented by an ethanol molecule which is also engaged in hydrogen bonding with one of the sulfonate oxygen atoms. The solvent-free complex 5 is associated into helical chains via Ag-O coordinative bonds which provide the silver atoms with a distorted planar T-shaped coordination.
Von Fluorsilylamiden zu Element-Silylamiden und Iminosilanen
Authors: Jendras Michael , Klingebiel Uwe , Noltemeyer Mathias
Published: August 2018

Ethyltrifluorosilane reacts with tert-butyllithium in a molar ratio 1:2 to give Et(CMe3)2SiF (1), which forms the aminosilane, Et(CMe3)2SiNH2 (2) in the reaction with NaNH2. The lithium salt of 2 and (Me3C)2SiF2 gives (Me3C)2SiF-NHSi(CMe3)2Et (3). 3 reacts with BuLi to give the lithium salt, (Me3C)2 SiF-NLi-Si(CMe3)2Et (4). tert-Butyl-(di-tert-butylfluoro)-silylaminoalanes (Me3C)2SiF-NCMe3-AlR2, R = Me (5), Et (6) are formed in the reaction of (Me3C)2SiF-NLi CMe3 (I) and ClAlR2. The lithium salt (Me3C)2SiF-NLi-Si(CMe3)2Me (III) reacts with BF3 under formation of the bis(silyl)aminodifluoroborane (Me3C)2SiF-N(BF2) Si(CMe3)2Me (7). In the reaction of I with F3SiPh rotamers of (Me3C)2SiF-NCMe3 SiF2Ph (8) are obtained.

Stannyl-silylamines are prepared in reactions of the lithium salts (Me3C)2SiF-NLiR, R = CMe3 (I), SiF(CMe3)2 (II); Si(CMe3)2Me (III) and the chlorostannanes ClSnMe3 (9,10,11) and Cl2SnPh2 (12), (Me3C)2SiF-NSnMe3-Si(CMe3)2R (9: R = F, 10: R = Me), (Me3C)2SiF-NSnMe3CMe3 (11), (Me3C)2SiF-NCMe3SnClPh2 (12). The NMR spectra of 9 and 10 prove the existence of rotamers.

The reaction of III with Me3SiOSO2 CF3 in n-hexane leads to the formation of the tris(silyl)amine 13, (Me3C)SiF-NSiMe3)2Si(CMe3)2Me. However, the analogous reaction of III and 4 with Me3SiOSO2CF3 in thf leads to the formation of the stable iminosilanes 14 and 15, (Me3C)2Si==N- Si(CMe3)R, R = Me (14), Et (15) crystal structures of 7 and 12 are presented.
Metallkomplexe mit biologisch wichtigen Liganden, CL [1]. 1,1-Dithiolato-Komplex von Palladium(II), Platin(II) und Gold(I) aus Diphenylmethylenglycinester sowie N,N-Dimethylglycinester und Schwefelkohlenstoff
Authors: Lang Markus A. , Sünkel Karlheinz , Ponikwar Walter , Beck Wolfgang
Published: August 2018

The 1,1-dithiolates Ph2C═N-C(CO2Et)═CS2
2− and Me2NC(CO2Et)═CS2
2− from diphenylmethylene glycine ethylester or N,N-dimethylglycine ester and CS2 react under basic conditions with chlorophosphine compounds of Pd(II), Pt(II) and gold(I) to give the complexes Ph2C═N-C(CO2Et)═CS2ML2, Me2N-C(CO2Et)═CS2ML2 (M = Pd, Pt; L = PPh3, 2L = Ph2PCH2CH2PPh2) and Ph2C═N-C(CO2Et)═CS2(AuPPh3)2, and Me2N- C(CO2Et)═CS2(AuPPh3)2.

The structures of the palladium complex Ph2C═N-C(CO2Et)═CS2Pd(PPh3)2 and of diphenylmethylene- L-alanine ethylester were determined by X-ray diffraction. Besides this S,S-complex also the (less stable) S,O-isomer could be detected.
Synthese monofluorierter cyclopropanoider Nucleosidanaloga
Authors: Csuk René , Thiede Gisela
Published: August 2018

Starting from a suitable protected (fluorocyclopropyl)methanol derivative a novel class of cyclopropanoid monofluorinated nucleoside analogues can be accessed very conveniently by a short sequence of steps.
Einkristalle des Neodym(III)-meta-Borats Nd(BO2)3 und -ortho-Borats Nd[BO3]/Single Crystals of the Neodymium(III) meta-Borate Nd(BO2)3 and ortho-Borate Nd[BO3]
Authors: Müller-Bunz Helge , Nikelski Tanja , Schleid Thomas
Published: August 2018

Pale violet, transparent, air- and water-resistant single crystals of the neodymium oxoborates Nd[BO3] and Nd(BO2)3 emerged from reactions of Nd2O3, NdF3 or NdCl3, and B2O3 in variable molar ratios during attempts to synthesize neodymium halide borates (e. g. Nd2F3[BO3] or NdCl(BO2)2). The preparations were carried out at 700 °C in sealed tantalum capsules using CsCl as a flux, or at 850 °C in evacuated silica ampoules with an excess of NdCl3 as fluxing agent. Neodymium ortho-borate λ -Nd[BO3] (orthorhombic, Pnma; a = 573.51(5), b = 505.64(4), c = 809.16(7) pm; Z = 4) is isotypic with aragonite-type CaCO3 containing quasi-planar, discrete [BO3]3− triangles (d(B-O) = 138 pm, 3×) and Nd3+ in ninefold oxygen coordination (d(Nd-O) = 239 - 269 pm, CN = 9). In the crystal structure of neodymium meta-borate Nd(BO2)3 (NdB3O6; monoclinic, C2/c; a = 983.24(9), b = 809.32(7), c = 637.71(6) pm, β = 126.639(8)°; Z = 4) both [BO3]3− triangles (d(B-O) = 133 - 142 pm, CN = 3) and [BO4]5− tetrahedra (d(B-O) = 145 - 149 pm, CN = 4) are present. They share common corners forming chains of the composition 1
∞{([(B1)(O1)e
2/1(O2)e
2/1][(B2)(O1)e
1/1(O2)e
1/1(O3)t
1/1]2)3−} (≡ 1
∞{(BO2)−}) which run parallel to the [101] direction and are interconnected by Nd3+ cations in tenfold coordination of oxygen atoms (d(Nd-O) = 238 - 280 pm, CN = 10).
The NaCl Adduct of the Iron-Indium Compound Fe2(CO)6(μ-CO)(μ-InR)2 [R = C(SiMe3)3] – a One-Dimensional Coordination Polymer with Sodium Oxygen Bridges
Authors: Uhl Werner , Schmock Fritjof , Petz Wolfgang
Published: August 2018

The organoindium subhalide [R(Cl)In-In(Cl)R]2 [R = C(SiMe3)3] 1 reacts with Na2[Fe2(CO)8] to form an iron-indium coordination compound which was isolated as the sodium choride adduct [Na(THF)4][Fe2(CO)6(μ-CO)(μ-InR)2Cl] 2. The iron atoms of 2 are bridged by a CO ligand and two InR groups, the indium atoms of which are further connected by the μ2-bridging chlorine atom. Four THF molecules and two oxygen atoms of terminal CO ligands of different anions span the coordination sphere of the sodium cations to give a one-dimensional coordination polymer in the solid state.
Effective Mummification Compounds Used in Pharaonic Egypt: Reactivity on Bone Alkaline Phosphatase
Authors: Koller Johann , Baumer Ursula , Kaup Yoka , Schmid Mirjam , Weser Ulrich
Published: August 2018

In Pharaonic Egypt from the Old Kingdom up to the Ptolemaic Period the deceased were pre-treated in the course of the mummification process using a wealth of embalming components including resins and many different wood tars. GC/MS studies allowed the elucidation of a great number of clearly separated compounds found in the ancient embalming material. Phenols, guaiacols, naphthalenes, monoterpenes, sesquiterpenoids, oxidised diterpene resin acids and triterpenoids were noticed. These results and particularly the detection of an unused embalming material shed some new light on the possible way as to how the different embalming materials might have been prepared and applied. It was striking to see the accordance of the present data with the well-known treatises by Herodotus (490-425 B. C.) and by Pliny the Elder (23/24-79 A. C.). The impact of the historical observations on modern science and in return the dramatic promotion of ancient texts stimulated by the present study is intriguing. An enzyme, alkaline phosphatase, bound inside mummified bones was a useful tool to reveal the efficacy of the embalming materials. Initial data showed that alkaline phosphatase isolated from embalmed bones from the Old Kingdom and the Ptolemaic Period was significantly more abundant and displayed a higher activity compared to the properties of the corresponding enzyme from non-treated mummified bones. Additionally, in a model study porcine ribs were pre-treated with four selected embalming compounds - guaiacol, limonene, α-pinene and p-cymene - and subsequently air-dried. Among the four selected compounds guaiacol was the most reactive species in the course of the preservation process. The specific activity of bone alkaline phosphatase rose 12-fold compared to that of the control. The enzyme itself remained unharmed as the observed relative molecular mass was surprisingly identical with the contemporary enzyme. It was again striking that the guaiacol derivatives were richly abundant in the unused embalming material mentioned above.
Vibrational Spectra of the Layered Compound [(VO2)2(4,4-bipy)0.5(4,4′- Hbipy)(PO4)]·H2O
Authors: Baran Enrique J , Lii Kwang-Hwa
Published: August 2018

The infrared and Raman spectra of the title complex were recorded and assignments for the VO+
2 , PO3-
4 and V-O and V-N skeletal vibrations are proposed. The results are of interest in relation to the vibrational-spectroscopic properties of the active site of vanadium haloperoxidases.
The Synthesis and Structure of the Two Hexafluorophosphate Salts {Cu[P(C7H7)3](CH3CN)2}PF6 and {Cu[P(C7H7)3]2}PF6 Containing the Ligand Tri(1-cyclohepta-2,4,6-trienyl)phosphane
Authors: Herberhold Max , Akkus Nilgün , Milius Wolfgang
Published: August 2018

The reactions of [Cu(CH3CN)4]PF6 (1) with one or two equivalents of tri(1-cyclohepta- 2,4,6-trienyl)phosphane lead to {Cu[P(C7H7)3](CH3CN)2}PF6 (2) and {Cu[P(C7H7)3]2}PF6 (3), respectively. According to the X-ray structure analyses, the cations in both 2 and 3 contain copper(I) in a pseudo-tetrahedral coordination sphere, in which a P(C7H7)3 ligand provides one or two olefinic bonds for weak interaction with the metal.
Hydroboration of Bis(trimethylsilylethynyl)silanes with 9-Borabicyclo[3.3.1]nonane. A New Route to 1-Sila-3-cyclopentenes and to a 1-Sila-2,4-cyclopentadiene
Authors: Wrackmeyera Bernd , Maisela Heidi E. , Miliusa Wolfgang , Bhattia Moazzam H. , Alia Saqib
Published: August 2018

The hydroboration of bis(trimethylsilylethynyl)silanes Me(R)Si(C≡CDSiMe3)2 1a (R = Me) and 1b (R = H) with 9-borabicyclo[3.3.1]nonane (9-BBN) does not give products related to the usual cis-1,2-hydroboration of one or both C≡C bonds. Instead, the major products obtained from 1a are the two isomers of 2,5-bis(trimethylsilyl)-2,5-bis[9-(9-borabicyclo[3.3.1]- nonyl)]-1-sila-3-cyclopentene 2a and 2a (silolenes), and from the reaction of 1b with 9-BBN solely the silolene 2b can be isolated. The silolenes 2a and 2b were studied by X-ray structural analysis. The reaction of 1a with 9-BBN in a 1:1 molar ratio gave a mixture of products, consisting of the silolenes 2a and 2a′, some unidentified material, and 2,5-bis(trimethylsilyl)- 3-[9-(9-borabicyclo[3.3.1]nonyl)]-1-sila-2,4-cyclopentadiene 3a. The silole 3a was then prepared in pure state by the reaction of 1a with 9-isobutyl-9-borabicyclo[3.3.1]nonane in boiling toluene, where the borane decomposes slowly into isobutene and 9-BBN which is trapped by 1a. The proposed structures of the heterocycles 2 and 3 in solution follow from a consistent set of NMR data (1H, 11B, 13C, 29Si NMR).
Darstellung von 2,3,8-substituierten Perhydrooxazolo[3,2-a]pyridinen und die Kristallstruktur von (E)-3-(2-Fluorbenzyliden)-1-[1,2-bis(2-fluorphenyl)- 2-hydroxyethyl]-3,4,5,6-tetrahydropyridiniumchlorid
Authors: Möhrle Hans , Mehrens Jutta , Tot Edith
Published: August 2018

2-Fluorobenzaldehyde (1) and pipecolic acid (7) react in dimethyl sulfoxide with potassium carbonate to form benzylidene-oxaindolizidines 4. These diastereomers yield with acids uniform salts, so from 4 with hydrogen chloride results (E)-3-(2-fluorobenzylidene)-1-[1,2-bis(2-fluorophenyl)-2- hydroxyethyl]-3,4,5,6-tetrahydropyridinium chloride (6·Cl), elucidated by X-ray structural analysis. Treatment of 6·Cl with alkali hydroxide regenerates 4. Similarly proline (13), when treated with two equivalents of 1, gives rise to oxapyrrolizidines 14. From 14 in presence of 1 the perchlorate of the benzylidene derivative 15·ClO4 can be obtained which is transformed to benzylideneoxapyrrolizidines 15 by bases.
Propargyl Derivatives with Silicon Carbon and Tin Carbon Bonds
Authors: Wrackmeyer Bernd , Tok Oleg L. , Bhatti Moazzam H. , Shahid Khadija
Published: August 2018

1-Dimethylamino-propyn-2-ylsilanes 3a [Me2Si(C≡C-CH2NMe2)2], 3b [Me(H)Si(C≡C-CH2N Me2)2], 4a [Me2(Cl)Si-C≡C-CH2NMe2], 4b [Me(H)(Cl)Si-C≡C-CH2NMe2], and 5 [Me2NCH2- C≡C-SiMe2SiMe2-C≡C- CH2NMe2] were prepared. Similarly, the 1-(pyrazol-1-yl)-propin-2-ylsilanes 6 and 7 (analogous to 3a and 5, respectively) and the tin compounds 8 [Me3Sn-C≡C-CH2-pz] (pz = pyrazol-1-yl) and 9 [Me2Sn(C≡C-CH2-pz)2] were synthesized, using the reaction of Li-C≡CCH2- pz (2-Li) with the respective chlorosilanes or tin chlorides. The compounds 3 to 9 were characterised in solution by a consistent set of 1H, 13C, 29Si and 119Sn NMR data.
Photo-Induced Chromiumcarbonyl Catalyzed Hydrosilylation of Conjugated Dienes with Triethylsilane: The Solvent Effect
Authors: Kayran Ceyhan , Özkar Saim , Akhmedov Vagif M.
Published: August 2018

Photocatalytic hydrosilylation of conjugated dienes (1,3-butadiene, 2-methyl-1,3-butadiene, 2,3- dimethyl-1,3-butadiene, trans-1,3-pentadiene) with triethylsilane was studied by using Cr(CO)5L (L = CO, P(CH3)3, P(OCH3)3, P(C6H5)3, P(C6H11)3, NC5H5) in two very different solvents, toluene and tetrahydrofuran, for comparison with the results found in n-hexane. In toluene, the photocatalytic hydrosilylation yields the same products as those in n-hexane, with the exception of trans- 1,3-pentadiene which gives cis-1-triethylsilyl-2-pentene as the sole product. However, each of the precursor complexes shows different catalytic activities in toluene and n-hexane. The hydrosilylation of 1,3-butadiene in toluene is, in general, significantly faster than that in n-hexane. By using Cr(CO)6, Cr(CO)5[P(CH3)3] or Cr(CO)5[P(OCH3)3] in toluene, the conversion of triethylsilane increases almost linearly as the reaction proceeds, indicating the stability of the active catalyst throughout the reaction, similar to that in n-hexane. While no hydrosilylation of 1,3-butadiene could be achieved with Cr(CO)5[P(C6H5)3] or Cr(CO)5(NC5H5) in n-hexane, the same precursor complexes appear to be active in toluene, though the conversion occurs at much lower rate compared to that obtained using Cr(CO)5[P(CH3)3] or Cr(CO)5[P(OCH3)3]. The precursor complex Cr(CO)5[P(C6H11)3] shows catalytic activity neither in toluene nor in n-hexane. No photocatalytic hydrosilylation of 1,3-butadiene with triethylsilane was observed in tetrahydrofuran by using any of the precursor complexes. The relative reactivity of conjugated dienes in the hydrosilylation was investigated by using triethylsilane in the presence of Cr(CO)5[P(OCH3)3] as catalyst in toluene, and the same reactivity order was obtained as in n-hexane solution: 1,3-butadiene > 3-methyl-1,3-butadiene > 2,3-dimethyl-1,3-butadiene > trans-1,3-pentadiene. For all of the dienes, one obtains higher conversion to hydrosilylated product in toluene than in n-hexane.
Chromophores as Elements of Structure for Pico Technology Optical Computers
Authors: Langhals Heinz , Saulich Sigrid
Published: August 2018

The transfer of the energy of optical excitation between the different chromophores of anthraquinone and perylene dyes has been controlled by their relative orientation. Such assemblies are basic components for optical computers on the picometer scale.
Triiodotelluronium Hexafluoroarsenate TeI3[AsF6]. The Crystal Structure of the Hemi SO2 Solvate and the Structure Relation to the Unsolvated Form
Authors: Beck Johannes , Steden Folker
Published: August 2018

TeI3[AsF6] is formed from Te, I2, and AsF5 in liquid SO2. At room temperature light red crystals of the hemi SO2 solvate TeI3[AsF6] · 0.5 SO2 are obtained from a saturated solution. The crystal structure (orthorhombic, Pnnm, a=1107.41(2), b=1866.58(3), c=1207.00(2) pm at 123 K, Z =8) consists of pyramidal TeI3
+ cations (Te-I = 267 pm), almost regular octahedral [AsF6]− anions and of SO2 molecules which show disorder for the O atom positions. A remarkable feature of the crystal structure is the arrangement of the TeI3
+ ions that are pairwise associated, facing each other with the I atoms and forming large voids between each other. This causes the significantly lower density of TeI3[AsF6] · 0.5 SO2 (3.88 Mgm−3) in comparison to the unsolvated form (4.20 Mgm−3, Pass more 1981).
peri-Interactions in Naphthalenes, 11 . A New Approach to the Investigation of Dative peri Bonding/A New Approach to the Investigation of Dative peri Bonding
Authors: Schiemenz Günter Paulus , Petersen Söke , Pörksen Simon
Published: August 2018

The failure of the sum of van der Waals radii axiom to provide information about donor-acceptor interactions in 8-dimethylamino-naphth-1-yl phosphines and their derivatives called for alternative methods. The coupling constants J(C,H) of the Me2N groups proved useful and indicate that in these compounds, N→P interactions are negligible.
Investigations on the Redox-Photochromism of Rhodium Acetonitrile Complexes
Authors: Knör Günther
Published: August 2018

The spectroscopic and photochromic properties of the dinuclear rhodium complex Rh2L10X4 (L = CH3 CN, X− = BF−
4 ) have been studied in acetonitrile solution. A reversible wavelengthdependent photoredox disproportionation of the dark-equilibrated dirhodium(II) compound occurs upon irradiation with quantum yields of φ = 0.04 at 254 nm and φ = 0.60 at 436 nm, respectively. While the photolysis products show conspicuous aggregation phenomena at higher concentrations, a straightforward pseudo-bimolecular recombination of the metastable fragments following second-order kinetics was observed in 5 × 10−5 M solution with k = 0.18 l mol−1 s−1 at 295 K. Both spectroscopic and kinetic results are consistent with the heterolytic formation of mononuclear rhodium(I) and rhodium(III) acetonitrile complexes in the course of the photochemical reaction.
Synthesis and Structures of Simple (Silylmethyl)(methyl)ethers
Authors: Mitzel Norbert W.
Published: August 2018

The compound Cl3SiCH2OCH3 was prepared by reacting ClCH2OCH3 with the Cl3SiH/NEt3 reagent. H3SiCH2OCH3 and F3SiCH2OCH3 were synthesized from Cl3SiCH2OCH3 by reduction with LiAlH4 and by fluorination with SbF3, respectively. The crystal structures of the low-melting compounds H3SiCH2OCH3 and F3SiCH2OCH3 were determined by X-ray diffraction of in situ grown crystals. Both compounds do not show any observable β -donor-acceptor interactions, but behave structurally like usual dialkylethers or silanes, as is obvious from the structural parameters in H3SiCH2OCH3 (<SiCO 108.4(3)-109.4(3)°, <COC 111.0(4)-111.6(4)°) and in F3SiCH2OCH3 (<SiCO 107.1(1), <COC 111.2(2)°). Earlier postulates of Si· · ·O interactions in compounds with SiCO units could thus not be confirmed on a structural basis.
Kinetics and Mechanism of Oxidation of Dimethyl Sulphoxide by Mono- and Di-Substituted N,N-Dichlorobenzenesulphonamides in Aqueous Acetic Acid
Authors: Gowda B.Thimme , Jayalakshmi K. L. , Jyothi K.
Published: August 2018

In an effort to introduce N,N-dichloroarylsulphonamides of different oxidising strengths, four mono- and five di-substituted N,N-dichlorobenzenesulphonamides are prepared, characterised and employed as oxidants for studying the kinetics of oxidation of dimethyl sulphoxide (DMSO) in 50% aqueous acetic acid. The reactions show first order kinetics in [oxidant], fractional to first order in [DMSO] and nearly zero order in [H+]. Increase in ionic strength of the medium slightly increases the rates, while decrease in dielectric constant of the medium decreases the rates. The results along with those of the oxidation of DMSO by N,N-dichlorobenzenesulphonamide and N,N-dichloro-4- methylbenzenesulphonamide have been analysed. Effective oxidising species of the oxidants employed in the present oxidations is Cl+ in different forms, released from the oxidants. Therefore the introduction of different substituent groups into the benzene ring of the oxidant is expected to affect the ability of the reagent to release Cl+ and hence its capacity to oxidise the substrate. Significant changes in the kinetic and thermodynamic data are observed in the present investigations with change of substituent in the benzene ring. The electron releasing groups such as CH3 inhibit the ease with which Cl+ is released from the oxidant, while electron-withdrawing groups such as Cl enhance this ability. The Hammett equation, log kobs = −3.19 + 1.05 σ , is found to be valid for oxidations by all the p-substituted N,N-dichlorobenzenesulphonamides. The substituent effect on the energy of activation, Ea and log A for the oxidations is also analysed. The enthalpies and free energies of activation correlate with an isokinetic temperature of 320 K.
NMR Spectroscopy of Tetra(propyn- 1-yl)silane in the Solid State and in Solution
Authors: Wrackmeyer Bernd , Tok Oleg L. , Badshah Amin
Published: August 2018

The crystal structure of tetra(propyn-1-yl)silane, Si(C≡CMe)4 1, has revealed a completely asymmetric molecule (point group C1). Since this finding concerns a single crystal, the bulk material of 1 was studied by solid-state 29Si and 13C MAS NMR. This confirmed the result of the X-ray analysis, and by comparison with previous NMR measurements of the tin analogue 1(Sn) it is concluded that 1 and 1(Sn) must have very similar solid-state structures which are in contrast to those known for other tetra(alkyn-1-yl)silicon and -tin compounds. The NMR data set of 1 in solution was completed by determination of the magnitude of coupling constants 1J(13C,13C).
Preparation and Characterization of 5,6-Dimethyl-5,6-dihydro-[1,4]diselenino[ 2,3-d][1,3]dithiole-2-thione and Similar Compounds
Authors: Papavassiliou George C. , Mousdis George A. , Anyfantis George C. , Assimomytis Nikos , Steele Barry R.
Published: August 2018

The compounds 5,6-dimethyl-5,6-dihydro-[1,4]diselenino[ 2,3-d][1,3]dithiole-2-thione, 5-methyl-5,6-dihydro-[1,4] diselenino[2,3-d][1,3]dithiole-2-thione and 5,6-dihydro- [1,4]diselenino[2,3-d]dithiole-2-thione were prepared and characterized analytically and spectroscopically.
Synthesis and Structure of a Zwitterionic Imidazolium 1,3-Dioxanide
Authors: Kuhn Norbert , Al Sheikh Ahmed , Steimann Manfred
Published: August 2018

{Bis(methylthio)methylene}-2,2-dimethyl-4,6-dioxo-1,3- dioxane (7) reacts with cis-1,2-diamino-1,2-dicyanoethene to give 2,2-dimethyl-4,6-dioxo-5-{2-(4,5-dicyano)} imidazolio-1,3-dioxan-5-yl-imidazolium ylide (8) as a stable crystalline solid in good yield. The crystal structure of 8 × C3H6OS is discussed.
Synthesis, Crystal Structure and Spectroscopic Properties of a Dinuclear Nickel(II) Complex Bridged by an Alkoxide and a μ-Pyrazolate Ligand
Authors: Kara H. , Elerman Y. , Elmali A.
Published: August 2018

A nickel(II) complex, [Ni2(L)(3,5-prz)], (L = 1,3-bis(2-hydroxy-5-bromosalicylidene amino) propan-2-ol; 3,5-prz = 3,5-dimethylpyrazolate), was synthesized and characterized by means of elemental analysis, infrared and electronic spectra. The crystal structure of the complex has been determined by X-ray diffraction. The nickel(II) ions are bridged by the alkoxo group of the ligand and the N atoms of the μ-pyrazolate group. Each nickel ion is coordinated by two O atoms and two N atoms, forming a square with trans-N2O2 geometry.
Synthesis of trans-Configurated Spacered Nucleoside Analogues Comprising a Difluorocyclopropane Moiety
Authors: Csuk René , Eversmann Leo
Published: August 2018

A novel class of trans-configurated difluorinated cyclopropanoic nucleoside analogues containing a methylene spacer between the cyclopropane ring and the heterocycle has been prepared. Some of these compounds showed weak anti-HIV activity in preliminary screenings.
Synthesis and Characterization of Copper(II) and Zinc(II) Complexes Containing 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone
Authors: Dey Subrata Kumar , Bag Bappaditya , Dey Dilip Kumar , Gramlich V. , Li Yadong , Mitra Samiran
Published: August 2018

The synthesis, structure, and physical properties of a series of mononuclear complexes viz. [Cu(L)2] 1, [CuL2(CH3O)2] 2 and [Zn(L)2] 3 (where L = 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP)) are presented. The complexes were characterized by elemental analysis, IR and electronic spectroscopy (1 and 2), magnetic measurements at room temperature (1 and 2) and thermogravimetric analysis. The structures of all the three complexes were determined by single crystal X-ray diffraction studies. The coordination geometry around complexes CuL2 (1) and ZnL2 (3) is slightly distorted square planar while the geometry around Cu(II) of [Cu(L)2(CH3O)2] (2) is distorted octahedral with four oxygen atoms of two PMBP ligand occupying the equatorial positions and two methanol molecules occupying the two axial positions.
Reactivity of Alkoxyethynyl(trimethyl)silane, -germane and -stannane towards Trialkylboranes. Organometallic-Substituted Enol Ethers
Authors: Wrackmeyera Bernd , Gruener Sergej V. , Zolotareva Alla S.
Published: August 2018

Methoxyethynyl(trimethyl)silane (1a) reacts at 100°C very slowly with triethylborane (4) to give a mixture of alkenes, one of which is the 1,1-organoboration product (Z)-1-methoxy-1-trimethylsilyl- 2-diethylboryl-but-1-ene (7a). Methoxyethynyl(trimethyl)germane (2a) reacts within minutes at 60 - 70°C with 4, tripropylborane (5) and 9-ethyl-9-borabicyclo[3.3.1]nonane (6) by 1,1-organoboration in the usual regio- and stereospecific way to give the corresponding alkenes (9a - 11a). The analogous reactions of the ethoxyethynyl(trimethyl)germane (2b) require longer heating and are accompanied by decomposition of 2b. Ethoxyethynyl(trimethyl)stannane (3b) reacts with the trialkylboranes 4- 6 already below room temperature by 1,1-organoboration to give the alkenes (12b - 14b) in quantitative yield. The compound 3b also reacts with the alkenes, e.g. 9a, 13b, 14b, to give novel organometallicsubstituted dienes. All products were characterised by multinuclear magnetic resonance spectroscopy (1H, 11B, 13C, 29Si, and 119Sn NMR).
Synthese flexibler difluorierter cyclopropanoider Nucleosidanaloga / Synthesis of Flexible Difluorinated Cyclopropanoid Nucleoside Analogues
Authors: Csuk René , Eversmann Leo
Published: August 2018

A novel class of difluorinated cyclopropanoic nucleoside analogues containing a hydroxypropyl group and a methylene spacer between the difluorocyclopropane ring and the heterocycle has been prepared.
Electroreduction of Organic Compounds, 34 [1]. Cathodic Dehalogenation of Chloroarenes with Electron-Donating Substituents
Authors: Kranz Olaf , Voss Jürgen
Published: August 2018

The electrochemical reduction of chlorinated arenes with electron-donating substituents, i. e. chlorotoluenes, -anisoles and -phenols, is studied. Preparative electrolyses are run in various solventsupporting electrolytes under potentiostatic and galvanostatic conditions at lead or carbon cathodes. A partial and mostly regioselective hydrodechlorination of compounds with two or more chloro substituents is possible under suitable conditions. The replacement of one single chloro substituent, in particular in a para-position, is difficult. Highly toxic and persistent oligochloro derivatives are thus transformed into less problematic compounds with a low degree of chlorination. The chlorine content of real-life materials such as extracts of soil contaminated with chlorinated phenols and Nitrofen® can also be significantly decreased by electroreduction.
Isolation, Structure Elucidation and Activity of Anthracycline Acetates from a Terrestrial Streptomyces sp.
Authors: Fotso Serge , Maskey Rajendra P. , Grün-Wollny Iris , Laatsch Hartmut
Published: August 2018

The red coloured ethyl acetate extract of the Streptomyces sp. isolate GW37/3236 delivered the two new antibiotics 13-O-acetyl-bisanhydro-13-dihydrodaunomycinone (3c) and 4,13-O-diacetylbisanhydro- 4-O-demethyl-13-dihydrodaunomycinone (3d) and additionally several known compounds. The quinones 3c and 3d are the first naturally occurring quinone acetates. Their structures were derived by comparison of the NMR data with those of bisanhydro-13-dihydrodaunomycinone (3b) and by interpretation of the 2D NMR data accompanied by the molecular weight and formula. 2-Acetamido-3-hydroxybenzamide (5) was also isolated from the extract and was identified by comparison of the NMR data with those of 2-acetamidobenzamide and by 2D NMR correlations. 6,9,11- Trihydroxy-4-methoxy-5,12-naphthacenedione (4) is isolated for the first time as a natural product.
Synthesis of Spacered Cyclopropanoid Muramyldipeptide Analogues as Potential Immunostimulants
Authors: Csuk René , Göthe Gunnar
Published: August 2018

A novel class of cyclopropanoic muramyldipeptide analogues containing an additional methylene spacer between the cyclopropane ring and the lactyl residue has been prepared by a straightforward synthesis starting from isopropyl (R)-lactate.
Verbindungen mit Pentelid-Hanteln M2: AI
II M6 und AII
11M10 (A = Rb, Cs, Ba; M = Sb, Bi) / Compounds with Pentelide Dumbbells M2: AI
11M6 and AII
11M10 (A = Rb, Cs, Ba; M = Sb, Bi)
Authors: Emmerling Franziska , Längin Nina , Pickhard Frank , Wendorff Marco , Röhr Caroline
Published: August 2018

The new ternary alkali pentelides A11M6 (A = Rb, Cs; M = Sb/Bi) all contain non electron-precise isolated dumbbells statistically composed of Sb/Bi. Their phase ranges as determined from single crystal data were found to be on the Sb-rich side of the overall composition A11Sb6−xBix in the case of the Rb compound (i. e. Rb11Sb5.4Bi0.6: orthorhombic Immm, a = 766.7(3), b = 1052.2(3), c = 1732.7(6) pm, Z = 4, R1 = 0.0554), and on the Bi-rich side of the overall composition A11Sb6−xBix in the case of A = Cs (i.e. Cs11Sb1.6Bi4.4). In the series of known alkaline earth compounds A11M10, containing pentelide dumbbells among isolated Zintl anions, a redetermination of the structure of Ba11Sb10 (orthorhombic, Immm, a = 1265.3(2), b = 1316.1(3), c =1947.2(5) pm, Z = 4, R1 = 0.0724) shows, that it represents a distorted variant of the tetragonal Ho11Ge10 structure type. This distortion is not only of crystallographic importance, as it results in a major change in the nature of the anions and their bonding, which is supported by DFT band-structure calculations. Likewise, the Zintl phase BaSb2 (monoclinic, P21/m, a = 1167.9(9), b = 438.1(5), c = 1257.1(9) pm, β = 100.53(2)°, Z = 6, R1 = 0.0648) crystallizes with a superstructure of the CaSb2-type previously reported.
Zur Reaktion von 2,3-Dihydro-1,3-diisopropy1-4,5-imidazol-2-yliden mit Bromderivaten der Meldrumsäure [1, 2] / On the Reaction of 2,3-Dihydro-1,3-diisopropy1-4,5-dimethylimidazol-2-ylidene with Bromine Derivatives of Meldrum’s Acid [1, 2]
Authors: Kuhn Norbert , Al-Sheikh Ahmed , Schwarz Simon , Steimann Manfred
Published: August 2018

The Imidazolium salts [ImH][MelBr] (7) and [ImBr][MelBr] (8) have been obtained from the carbene Im (5) and the Meldrum’s acid derivatives MelHBr (3) and MelBr2 (4). The crystal structure analyses of 7 and 8 reveal the presence of ion pairs linked by short OH (7: 2.163 Å ) and OBr (8: 2.872 Å ) contacts.
Triethoxysilane, Tetraethoxysilane and Hexaethoxydisiloxane – Three Complementary Reagents for the Synthesis of Hydrogen-Rich Silylarenes
Authors: Minge Oliver , Nogai Stefan , Schmidbaur Hubert
Published: August 2018

Triethoxysilane HSi(OEt)3, tetraethoxysilane Si(OEt)4 and hexaethoxydisiloxane Si2O(OEt)6 have been probed as reagents for the synthesis of hydrogen-rich silyl-arenes Ar(SiH3)n. A large set of new silyl-arenes, varying in their substitution patterns and grades, have been prepared. The results establish the two new silylating agents HSi(OEt)3 and Si2O(OEt)6 as particularly useful alternatives to Si(OEt)4. The products, which include trihydrosilyl-substituted methylbenzenes, naphthalenes and ferrocenes, have been characterized by NMR and IR spectroscopy, mass spectrometry and single crystal X-ray diffraction.
Dimeric Methylzinc Bis(2-pyridylmethyl)amide – Synthesis, Molecular Structure and Reaction with Dimethylzinc
Authors: Westerhausen Matthias , Kneifel Alexander N , Lindner Ivonne , Grčić Jelena , Nöth Heinrich
Published: August 2018

The zincation of bis(2-pyridylmethyl)amine with dimethylzinc yields dimeric methylzinc bis(2-pyridylmethyl)amide (1) with a central Zn2N2 cycle with Zn-N distances of 204.8(5) and 209.8(4) pm. The Zn-C bond length of 197.0(5) pm lies in the characteristic region. The addition of dimethylzinc to 1 leads to an opening of the Zn2N2 cycle and the formation of tetramethyltrizinc bis[bis(2-pyridylmethyl)amide] (2). The dimethylzinc molecule coordinates to a pyridyl and an amide group, the C-Zn-C bond angle of 135.3(3) being rather large. In solution, compound 2 loses methane at room temperature and the intramolecular metalation product tris(methylzinc) bis(2- pyridylmethyl)amide 1,3-di(2-pyridyl)-2-azapropane-1,2-diide (3) precipitates. The newly formed Zn-C bond is extremely long at 219.7(5) pm.
Synthesis and Structural Relationship of the Ternary Indides Sc3Ni2.10(5)In3.60(5), Sc3Ni2.14(2)In3.76(2), ScPd0.981(2)In and Sc3Rh1.594(9)In4
Authors: Lukachuk Mar’yana , Zaremba Vasyl’ I , Hoffmann Rolf-Dieter , Pöttgen Rainer
Published: August 2018

The ternary scandium transition metal indides Sc3Ni2.10(5)In3.60(5), Sc3 Ni2.14(2)In3.76(2), ScPd0.981(2)In, and Sc3Rh1.594(9)In4 have been synthesized from the elements in glassy carbon crucibles in a high frequency furnace or by arc-melting. They have been investigated by X-ray powder diffraction and the structures refined on the basis of single crystal diffractometer data: Lu3Co1.87In4 type, P6̄, a = 745.7(1), c = 342.85(7) pm, wR2 = 0.0689, 545 F2, 24 parameters for Sc3Ni2.10(5)In3.60(5), a = 753.63(7), c = 344.3(1) pm, wR2 = 0.0362, 792 F2, 22 parameters for Sc3Ni2.14(2)In3.76(2), P6̄2m, ZrNiAl type, a = 764.1(2), c = 345.90(8) pm, wR2 = 0.0333, 326 F2, 15 parameters for ScPd0.981(2)In, and P6̄, a = 769.4(1), c = 684.1(1) pm, wR2 = 0.0526, 1097 F2, 35 parameters for the new structure type Sc3Rh1.594(9)In4. In the three structure types the scandium atoms build trigonal prisms. The latter are filled exclusively by palladium atoms in ScPd0.981(2)In, while transition metal and indium atoms fill these sites in the other three structures. The different coloring of the trigonal prismatic sites leads to a symmetry reduction for the structures of Sc3Ni2.10(5)In3.76(5), Sc3Ni2.14(2)In3.76(2) and Sc3Rh1.594(9)In4. The structural relationship is described on the basis of a group-subgroup scheme. Chemical bonding in these intermetallics is briefly discussed.
Tris(2-isocyanocarbonsäureester)-Halbsandwich-Komplexe [(Aren)M(CNCHR1CO2R2)3]2+ (M = Ru, Rh, Ir) / Tris(2-isocyanocarboxylic Acid Ester) – Halfsandwich Complexes [(arene)M(CNCHR1CO2R2)3]2+ (M = Ru, Rh, Ir)
Authors: Lang Markus A , Mayer Peter , Beck Wolfgang
Published: August 2018

By reaction of chloro bridged halfsandwich complexes with silver salts and subsequent addition of isocyanocarboxylic acid esters the isocyanide complexes [(arene)M(CNCHR1CO2R2)3]2+(X−)2 (arene = C6Me6, p-cymene, M = Ru; arene = C5Me5, M = Rh, Ir), (R1 = H, Me, CHMe2, CH2Ph, X = BF4, CF3 SO3) were prepared and characterized. The structure of [(C5Me5) Ir(CNCH2CO2Et)3]2+(CF3SO3
−)2 was determined by X-ray structure analysis.
Palladium(II) Complexes with Benzoxazol-2-ylidene Ligands: Crystal Structures of trans-Chloro(benzoxazol-2-ylidene)- bis(triphenylphosphine)palladium(II) Chloride and cis-Diiodo(benzoxazol-2-ylidene)(triphenylphosphine)palladium(II)
Authors: Hahn F. Ekkehardt , Lügger Thomas , Beinhoff Matthias
Published: August 2018

The palladium(II) complexes trans-[PdCl(L)(PPh3)2]Cl, 5, and cis-[PdI2(L)PPh3], 7, (L = benzoxazol- 2-ylidene) have been synthesized by treatment of the complexes trans-[PdX2(PPh3)2] (4: X = Cl, 6: X = 1) with 2-(trimethylsiloxy)pheny1 isocyanide 1, and subsequent hydrolysis of the Si-O bond. The crystal structures of 5 and 7*CH2Cl2 were established by X-ray diffraction. NMR and IR studies indicate, that the unexpected cis-configuration of 7 obtained from trans-[PdI2(PPh3)2] is not the result of a solution equilibrium between the cis- and the trans-isomers.
Isolation and Structure of a New Ceramide from the Basidiomycete Hygrophorus eburnesus
Authors: Qu Yan , Zhang Hong-Bin , Liu Ji-Kai
Published: August 2018

A new ceramide, named hygrophamide (1), was isolated from the fruiting bodies of the basidiomycetes Hygrophorus eburnesus Fr.. The structure of the compound was elucidated as (2S, 3S, 4R, 2’R)-2-(2’-hydroxy-9’Z-ene-tetracosanoylamino)-octadecane- 1,3,4-triol (1) by spectral and chemical methods.
Indirect Nuclear Spin-Spin Coupling Constants 1J(17O,13C) in Derivatives of Carbon Dioxide and Carbon Monoxide – Density Functional Theory (DFT) Calculations
Authors: Wrackmeyer Bernd
Published: August 2018

Calculations of spin-spin coupling constants 1J(17O,13C) in carbon dioxide (1) carbon monoxide (2) and several derivatives using density functional theory (DFT) have been carried out. This coupling constant possesses a positive sign [reduced coupling constant 1K(17O,13C)<0] except for the parent acylium cation [H-CO]+ (4a). It is shown that the Fermi contact term (FC) is positive [< 0 for 1K(17O,13C)] and that there are significant contributions from spin-dipole (SD) and paramagnetic spin-orbital (PSO) interactions
Microbial Transformation of Antifertility Agents, Norethisterone and 17α-Ethynylestradiol
Authors: Choudhary Muhammad I. , Musharraf Syed G. , Ali Rahat A. , Atif Muhammad , Rahman Atta-ur
Published: August 2018

The microbial transformation of oral contraceptive norethisterone (1) by Cephalosporium aphidicola afforded an oxidized metabolite, 17α-ethynylestradiol (2), while the microbial transformation of 2 by Cunninghamella elegans yielded several metabolites, 19-nor-17α-pregna-1,3,5 (10)- trien-20-yne-3,4,17β -triol (3), 19-nor-17α-pregna-1,3,5 (10)-trien-20-yne-3,7α,17β -triol (4), 19- nor-17α-pregna-1,3,5 (10)-trien-20-yne-3,11α,17β -triol (5), 19-nor-17α-pregna-1,3,5 (10)-trien-20- yne-3,6β ,17β -triol (6) and 19-nor-17α-pregna-1,3,5 (10)-trien-20-yne-3,17β -diol-6β -methoxy (7). Metabolite 7 was found to be a new compound. These metabolites were structurally characterized on the basis of spectroscopic techniques
A New Phenanthrene Alkaloid, Romucosine I, form Rollinia mucosa Baill
Authors: Kuo Reen-Yen , Chen Chung-Yi , Lin An-Shen , Chang Fang-Rong , Wu Yang-Chang
Published: August 2018

Bioactivity-directed fractionation led to the isolation of a new N-(methoxycarbonyl) phenanthrene alkaloid, romucosine I (1), along with three known N-(methoxycarbonyl) alkaloids, romucosine C (2), tuduranine (3), and promucosine (4). The structures of these compounds were identified on the basis of spectral data and chemical evidence. A proposed biogenesis about these isolates is also reported in this paper