Volume 65, Issue 6

We report the structures of nineteen new amine silver halide complexes, some of them featuring previously unknown structure types, stoichiometries (such as L 4 Ag 5 X 5 ) and coordination numbers. Known structures have been included and analysed for non-classical hydrogen bonds. We have identified three important factors for the formation of certain structure types. First, Ag-X bonds that form a central framework, typically staircase-shaped. Secondly, hydrogen bonds or other secondary interactions competing with these leading to a weakening or disappearance of some of the central Ag-X bonds. Finally, the polarity of the substituent at nitrogen and the silver halides influence the stoichiometry of the complex. Graphical Abstract Einfaches System, vielfältige Strukturen: Eine Neuuntersuchung der (Amin)halogenidosilber(I)-Komplexe/ A Simple System with many Structural Variants: A Reexamination of (Amine)halogenidosilver(I) Complexes

Hydrothermal reaction of Zn(NO 3 ) 2 ·6H 2 O with 2,2´,3,3´-oxydiphthalic acid (H 4 odpa) and pyridine (py) at 120 °C yielded a one-dimensional metal-organic coordination polymer {[Zn 2 (2,2´,3,3´- odpa)(py) 3 (H 2 O)]·H 2 O} n (1), which is further connected together through hydrogen bonds, π· · ·π and C−H· · ·π interactions to give a three-dimensional supramolecular network. The thermal stability of complex 1 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). Compound 1 exhibits photoluminescence with an emission maximum at ca. 430 nm upon excitation at 350 nm. Graphical Abstract Hydrothermal Synthesis, Crystal Structure and Properties of a 1DMetal- Organic Coordination Polymer {[Zn2(2,2´,3,3´-odpa)(py) 3 (H 2 O)]·H 2 O} n

The reactions of the chlorido-bridged complexes [Cp*M(Cl)(μ-Cl)] 2 (M = Rh, Ir) with Schiff bases (P-N-O) from 2-(diphenylphosphino)benzaldehyde and α-amino acid esters afford the complexes Cp*M(Cl) 2 (P-N-O) in which the ligands function as monodentate P donors (M = Ir) or as bidentate P-N donors (M = Rh). These complexes can be converted into cationic complexes [Cp*M(Cl)(P-NO)] + with bidentate P-N ligands by treatment with NH4PF6. The cationic complexes [Cp*M(Cl)(PN- O)] + Cl − have been detected also in solutions of Cp*M(Cl) 2 (P-N-O). The P-N-coordinated complex [Cp*Rh(Cl)(Ph 2 P-C 6 H 4 -C(H)=N-C(H)(CH 2 Ph)CO 2 Me)] + PF 6 − was characterized by X-ray diffraction. From Cp*M(Cl) 2 (P-N-O) and AgBF 4 or AgPF 6 (molar ratio 1 : 2) the dicationic complexes [Cp*M(P-N-O)] 2+ are formed in which the ester group is also coordinated to the metal atom. The Schiff base from 2-(diphenylphosphino)benzaldehyde and allylglycine ester acts as a tridentate ligand, however with coordination of the C=C allyl group instead of the ester function. Graphical Abstract Metal Complexes of Biologically Important Ligands, CLXXV [1]. Pentamethylcyclopentadienyl Halfsandwich Complexes of Rhodium(III) and Iridium(III) with Schiff Bases from 2-(Diphenylphosphino)- benzaldehyde and α-Amino Acid Esters

Treatment of tetramethylpyrazole, N 2 C 3 Me 4 , with equimolar quantities of di(tert-butyl)aluminum hydride leads to the addition of an Al-H bond to one of the C=N double bonds. The dimeric product (1) contains a central six-membered Al 2 N 4 ring in which two t Bu 2 Al + units are bridging two N 2 C 3 heterocycles. In the zwitterionic, non-centrosymmetric compound one aluminum atom is coordinated by two imino nitrogen atoms, while the second one is bonded to two amide nitrogen atoms. No double hydroalumination occurs upon treatment of tetramethylpyrazole with two equivalents of the hydride. Instead, an adduct (2) of the monomeric hydroalumination product with di(tert-butyl)aluminum hydride was isolated in which the two aluminum atoms are connected by a 3c-2e Al-H-Al bond. A unique trinuclear compound (3) is obtained upon reaction of tetramethylpyrazole with an excess of the sterically less shielded diethylaluminum hydride. It contains two different N 2 C 3 heterocycles: One still contains a C=N double bond similar to that in compounds 1 and 2, while the second one is completely reduced by double hydroalumination to give a saturated heterocycle. The two rings are bridged by three AlEt 2 groups. Deprotonation results upon treatment of 3,5-diphenylpyrazole, N 2 C 3 H 2 (C 6 H 5 ) 2 , with di(tert-butyl)aluminum hydride. Graphical Abstract Treatment of Tetramethylpyrazole and 3,5-Diphenylpyrazole with Dialkylaluminum Hydrides - Hydroalumination versus Deprotonation

A new cobalt(II) complex, [Co(H 2 O) 4 (nia) 2 ](suc)·(H 2 suc) [nicotinamide = nia, succinate = suc 2− ], has been synthesized and characterized by elemental analysis, IR, TG-DTA and single-crystal X-ray diffraction. It contains [Co(H 2 O) 4 (nia) 2 ] 2+ complex cations, uncoordinated suc 2− anios and H 2 suc species. In the complex cation the cobalt(II) ion is coordinated by four aqua and two nia ligands in a distorted octahedral geometry. The suc 2− dianion acts as a counter-ion, while H 2 suc is present as a molecule of solvation. A three-dimensional network is formed by O-H· · ·O and N-H· · ·O hydrogen bonds. The title complex exhibits luminescence in the solid state at room temperature. The magnetism of the complex was studied over the temperature range 1.8 - 300 K. Graphical Abstract Synthesis, Crystal Structure, Magnetic, Thermal and Fluorescent Properties of [Co(H 2 O) 4 (nia) 2 ](suc)·(H 2 suc)

9,10-Dibromo-anthracene was lithiated once or twice, and the products were reacted with different sulfurdiimides. The reactions yielded [(THF) 2 Li(N t Bu) 2 SAnBr] (1), [(Et 2 O)(LiBr)Li(N t Bu) 2- SAnBr] 2 (2), [Me 2 Al(NtBu) 2 SAnBr] (3), [{(THF) 2 Li(NR) 2 S} 2 An] (4: R = t Bu; 5: R = SiMe 3 ) and [{Me 2 Al(NSiMe 3 ) 2 S} 2 An] (6). All products were fully characterized by X-ray structure analysis, elemental analysis, NMR and mass spectroscopy. From the solution NMR spectra it is evident that the rotation about the S-C bond is hindered even at r. t. leaving all protons of the anthracene framework non-equivalent. Graphical Abstract Lithium and Aluminum Anthracenyldiimidosulfinates

To synthesize ligands that are capable of coordinating two metals, 1,4-dilithiumbenzene and 4,4´-dilithiumbiphenyl were reacted with different sulfurdiimides to give coupled diimidosulfinates. [(THF) 4 Li 2 {(NSiMe 3 ) 2 S} 2 biphenyl] (1) and [(THF) 1.5 Li 2 {(NSiMe 3 ) 2 S} 2 biphenyl] ∞ (2) could be isolated and structurally characterized. While 1 forms distinct molecules in the solid state, 2 crystallizes in infinite chains. The lithium complex with a benzene group as spacer could not be isolated due to co-complexed lithium bromide. Subsequent metal exchange reactions with dimethylaluminum chloride afforded [{Me 2 Al(NtBu) 2 S}2biphenyl] (3) and [{Me 2 Al(NSiMe 3 ) 2 S} 2 (C 6 H 4 )] (4). Graphical Abstract π-Spacer-coupled Diimidosulfinates

The title compound, [MgBr 2 (C 4 H 8 O) 4 ] (1a), forms twinned four-component monoclinic crystals as a new polymorph, space group P2 1 /n with Z´ = 2, in addition to the already known tetragonal polymorph (1b). Although the molecular parameters in the two polymorphs match very well, the packing patterns are significantly different. Furthermore, the correct constitution of the mixed halide bromo-chloro-tetrakis(tetrahydrofuran-κO)magnesium(II) (2) could be determined. Graphical Abstract Polymorphism of Dibromo-tetrakis(tetrahydrofuran-κO)magnesium(II)

Alkynylsilanes bearing one to four alkynyl groups at silicon, with organyl groups (Me, Ph, Vin), H, Cl at silicon, and with substituents H, n Bu, t Bu, Ph, C 6 H 4 -4-Me, 3-thienyl, CH 2 NMe 2 at the C≡C bond, were prepared, and their 13 C and 29 Si NMR data are reported. The results of X-ray structure analyses of three representative derivatives [di(phenylethynyl)dimethylsilane, di(phenylethynyl) methyl(phenyl)silane, and tri(phenylethynyl)methylsilane] are presented. The chemistry of mono- and dialkynylsilanes was further developed to prepare compounds with alternating Si atoms and C≡C bonds, affording new dialkynylsilanes as well as numerous new vinylsilanes which have also been characterized by 13 C and 29 Si NMR spectroscopy in solution. In the case of ethynyl(triphenylsilylethynyl) dimethylsilane, the molecular structure was determined by X-ray diffraction. Graphical Abstract Alkynylsilanes and Alkynyl(vinyl)silanes. Synthesis,Molecular Structures and Multinuclear Magnetic Resonance Study

Performing a standard Japp-Klingemann synthesis that involved diazotation of 2,6-dinitroaniline and reaction with pentane-2,4-dione in aqueous hydrochloric acid medium surprisingly yielded a mixture of the expected 2,6-dinitro- and the unexpected 2-chloro-6-nitro-substituted hydrazones. This mixture was isolated as solid-solution crystals containing the components in an approximate ratio of 1 to 2. Based on both, selected compounds of comparison that show the aromatic ring substituents changed in position and intermediate diazonium salts, potential causal connections of the unusual behaviour during the route of the particular Japp-Klingemann reaction were studied. X-Ray crystal structures of the relevant compounds have been determined to support the discussion. Graphical Abstract Unusual Behaviour During the Route of a Japp-Klingemann Reaction

A cleistanthane-type diterpene, compound 1, was isolated from the marine-derived Fusarium sp. FH-146. The structure of 1 was determined by 1D and 2D NMR spectroscopy. Compound 1 showed moderate antimicrobial, cytotoxic, and phytotoxic activities Graphical Abstract A Cleistanthane Diterpene From a Marine-derived Fusarium Species Under Submerged Fermentation

Chemical investigation of the EtOH extract from the tubers of Stephania succifera collected in Hainan Province of China resulted in the isolation of the two new alkaloids Cepharanone D (1) and N-formyl-asimilobine (2), and a known alkaloid, N-formyl-annonain (3). Their structures were elucidated by spectroscopic techniques (UV, IR, 1D and 2D NMR). The antimicrobial activities of the three compounds were also investigated. Graphical Abstract Antimicrobial Alkaloids from the Tubers of Stephania succifera

A new limonoid, trichiliton B (1), was isolated from the twigs and leaves of Trichilia connaroides. Its structure was elucidated on the basis of spectroscopic analyses, including application of ESI-MS, HR-ESI-MS, UV, IR, 1D and 2D NMR techniques Graphical Abstract A New Limonoid fromTrichilia connaroides

Two new abietane diterpene acids, pinyunins A (1) and B (2), a new lignan, 2-[2-hydroxy-5-(3- hydroxypropyl)-3-methoxyphenyl]-1-(2,3-dihydroxyphenyl)propane-1,3-diol (3), and eight known diterpenoids (4 - 11) were isolated from the bark of Pinus yunnanensis Franch. Their structures were elucidated by spectroscopic methods. Compounds 1 - 3 exhibited high inhibitions on Cox-2 (> 80 %) and low inhibitions on Cox-1 (< 50%), showing the trend of selective inhibition of Cox-2, while the positive controls NS-398 (Cox-2) and SC-560 (Cox-1) gave inhibitions of 97.09% and 61.30 %, respectively. Compounds 1 - 11 were evaluated for their cytotoxicity against five human cancer cell lines with Cisplatin as a positive control. Graphical Abstract Abietane Diterpenoids and a Lignan from Pinus yunnanensis

A facile route to single crystals of Nb 3 Br 8 by the reaction of NbBr 5 with the wall of the niobium reaction vessel at 800 °C is reported. The crystal structure (a = 707.87(5), c = 3895.7(6) pm, R3̄m, Z = 6) was determined from diffractometer data; the crystal data are compared with those obtained from film data in 1966 which were of already high precision. Triangular {Nb 3 } clusters with Nb-Nb distances of 288.6(2) pm are surrounded by 13 bromide ligands which bridge them to double layers, {Nb 3 }(μ 3 -Br4) i 1/1 (μ 2 - Br1) i (3/2)・2 (μ 1 -Br2) a-a 6/2 (μ 1 -Br3) a-a-a 3/3 that are stacked to a 12R structure. Graphical Abstract Triniobiumoctabromide, Nb 3 Br 8 , Revisited