Volume 64, Issue 4

Starting from CH-acidic tetradentate ligands H2L (1) and triethylamine, the synthesis and characterisation of four dinuclear iron(III) and gallium(III) cryptands [M 2 (L) 3 ] (3, 4) are reported. The structures of the ligand H 2 L (1a) and the triple helicate 3b were determined by X-ray diffraction analysis. The ferric complexes 3 were further characterised by Mössbauer spectroscopy and cyclic voltammetry. NMR spectroscopy proved the diamagnetic gallium(III) cryptands 4 to remain stable in solution for several days. Graphical Abstract {2}Metallocryptands of Iron and Gallium: Synthesis, Structure, and Properties [1]

Single-phase Pr 2 CBr was prepared by heating a mixture of PrBr 3 , Pr and C (1 : 5:3) to 1140 °C for 18 d. The crystal structure was investigated by X-ray single crystal diffraction (space group P6 3 /mmc, a = 3.8071(3), c = 14.7787(12) Å). In the structure the Pr atoms form C-centered octahedra condensed into Pr 2 C sheets via common edges; these sheets are separated by the Br atoms which are in a trigonal prismatic environment of Pr atoms. Pr 2 CBr is a black shiny compound with metallic conductivity. It is a ferromagnet with T c = 13.8(5) K. Graphical Abstract Pr 2 CBr: Ein Ferromagnet mit Pr 2 C-Schichten/ Pr 2 CBr: A Ferromagnet with Pr 2 C Layers

YF[SeO 3 ]-type rare-earth metal(III) fluoride oxoselenates(IV) MF[SeO 3 ] (M = Y, Ho-Lu) crystallize monoclinically in space group P2 1 /c (no. 14) with Z = 4. Obeying the lanthanoid contraction, the lattice parameters decrease successively from a = 657.65(7), b = 689.71(7), c = 717.28(7) pm and β = 99.036(5)° for YF[SeO 3 ] at 298 K to a = 648.39(6), b = 681.28(7), c = 705.81(7) pm and β = 98.657(5)° for LuF[SeO 3 ] at 100 K (LT-LuF[SeO 3 ], LT ≡ Low Temperature). The M 3+ cations are occupying the general site 4e. Contrary to the triclinic structure of RT-LuF[SeO 3 ] (RT ≡ Room Temperature; CN(Lu 3+ ) = 7) the higher coordination number eight is achieved for the M 3+ cations in all YF[SeO 3 ]-type compounds. This results in [MO 6 F 2 ] 11 − polyhedra (d(M-O) = 228 - 243/225 - 239 plus 263/258 pm, d(M-F) = 219/216 pm, M = Y/Lu), which are connected via common O・ ・ ・O edges to form infinite chains 1 ∞ {[MO e 4/2 O t 2/1 F t 2/1 ] 7− } (e ≡ edge-sharing, t ≡ terminal) running along [010]. Neighboring chains share common O3・ ・ ・O3 and O3・ ・ ・F edges generating 2 ∞ {[M(O3) 3/3 (O2) 2/2 (O1) 1/1 F 2/2 ] 4− } sheets parallel to the (100) plane. Finally, these 2 ∞ {[MO 3 F] 4− } sheets are interconnected by Se 4+ cations, which appear in isolated ψ 1 -tetrahedral [SeO 3 ] 2− anions (d(Se-O) = 167 - 175 pm). For the synthesis of the YF[SeO 3 ]-type rare-earth metal(III) fluoride oxoselenates( IV) MF[SeO 3 ] (M = Y, Ho-Lu), the rare-earth metal sesquioxides (M 2 O 3 ) and trifluorides (MF 3 ), and selenium dioxide (SeO 2 ) in molar ratios of 1 : 1 : 3 with the fluxing agent CsBr were reacted within five days at 700 - 750 °C in evacuated graphitized silica ampoules. Graphical Abstract Die Selten-Erd-Metall(III)-Fluorid-Oxoselenate(IV) MF[SeO 3 ] (M = Y, Ho–Lu) imYF[SeO 3 ]-Typ/ The Rare-Earth Metal(III) Fluoride Oxoselenates(IV) MF[SeO 3 ] (M = Y, Ho–Lu) with YF[SeO 3 ]-type Structure

The equiatomic germanides REPtGe with the heavy rare earth elements (RE) have been reinvestigated with respect to platinum-germanium ordering. The compounds were prepared by arc-melting of the elements followed by annealing for two weeks at 1070 K. The REPtGe germanides crystallize with the TiNiSi-type structure, space group Pnma. The structures of ErPtGe (a = 692.01(5), b = 432.03(4), c = 753.19(5) pm, wR2 = 0.0523, 435 F 2 , 20 variables) and the new germanide LuPtGe (a = 683.1(1), b = 429.2(1), c = 750.3(1) pm, wR2 = 0.0696, 358 F 2 , 20 variables) have been refined from single crystal diffractometer data. These structures exhibit three-dimensional [PtGe] networks with strong Pt-Ge intra- (251 - 255 pm in LuPtGe) and weaker interlayer (272 pm in LuPtGe) interactions. The crystal chemical peculiarities of the whole REPtGe series are briefly discussed. Graphical Abstract Platinum-Germanium Ordering in the Germanides REPtGe with the Heavy Rare Earth Elements

The existence of the C 2v symmetric closed-shell di[gold(I)]hydronium cation [Au 2 H] + (1), is predicted. It is shown that 1 is the smallest possible molecular species containing aurophilic contacts. Equilibrium structural parameters, vibrational frequencies and formation energies of 1 from Au + and AuH, have been calculated, employing a series of highly correlated but available standard relativistic ab initio methods up to CCSD(T) level of theory and all-electron basis sets of quadruple-ζ quality with double polarizations. Relativistic effects have been taken into account by employing pseudorelativistic electron core potentials (ECP) or a scalar relativistic treatment using a Douglas-Kroll-Heß Hamiltonian of 2nd, 3rd and 4th order (DKH2, DKH3, DKH4). Graphical Abstract The Smallest “Aurophilic Species”

An octamolybdate-supported complex, {[Zn(phen) 2 ] 2 (γ-Mo 8 O 26 )} (phen = 1,10-phenanthroline) (1), has been obtained and characterized by IR spectroscopy, TGA analysis and single crystal X-ray diffraction. Crystal data: C 48 H 40 O 26 N 8 Mo 8 Zn 2 , monoclinic, P2 1 /n, a = 12.986(5), b = 16.704(5), c = 13.996(5) Å , β = 106.551(5)°, V = 2910.2(18) Å 3 , Z = 2. The structure of compound 1 consists of a γ -octamolybdate cluster covalently attached to two [Zn(phen) 2 ] 2+ complexes. The complexes are tightly packed via C-H・ ・ ・O contacts between phen and [γ-Mo 8 O 26 ] 4− anions Graphical Abstract Non-hydrothermal Synthesis of a Complex {[Zn(phen) 2 ] 2 (γ-Mo 8 O 26 )} Constructed from [γ-Mo 8 O 26 ] 4– Anions

Trimethyl- and triethyl(propyn-1-yl)tin react with 9-borabicyclo[3.3.1.]nonane (9-BBN) mainly by exchange of the propynyl group against hydrogen, accompanied by numerous side reaction. This is in contrast to the findings for other alkynyltin compounds bearing a second bulky substituent at the C≡C bond. The exchange product, 9-propyn-1-yl-9-borabicyclo[3.3.1]nonane, was isolated as its crystalline pyridine adduct and fully characterised by NMR spectroscopy in solution and X-ray structural analysis in the solid state. Graphical Abstract Reaction of 9-Borabicyclo[3.3.1]nonane with Alkyn-1-yltin Compounds. Molecular Structure of the 9-Propyn-1-yl-9-borabicyclo[3.3.1]nonane Pyridine Adduct

A new centrosymmetric trinuclear Zn(II) complex [Zn 3 L 2 (CH 3 COO) 4 ] (1) has been synthesized by the reaction of Zn(CH 3 COO) 2 · 2H 2 O with a tridentate N,N,O-donor Schiff base ligand HL [C 5 H 4 NC(CH 3 )=NC 6 H 4 (OH)] and systematically characterized by elemental analysis, FT-IR, UV/Vis and thermal methods. Single crystal X-ray structure analysis reveals that three Zn(II) centers are in two different coordination environments. Two terminal Zn(II) centers adopt a distorted squarepyramidal geometry leaving the central Zn(II) in a distorted octahedral environment. Two adjacent metal centers are connected through single μ 2 -phenolato as well as double μ-acetato-O,O´ syn-syn bridges. Fluorescence properties of the complex as compared to the ligand indicate that the former can serve as a potential photoactive material. Graphical Abstract Synthesis, Structure and Fluorescence Properties of a Trinuclear Zn(II) Complex with N,N,O-donor Schiff Base Ligands and Bridging Acetates

The in situ formed hydrazone Schiff base ligand (E)-N´-(2-hydroxy-3-methoxybenzylidene)- benzohydrazide (L 2− ) reacts with bis(acetylacetonato)titanium(IV) oxide in methanol to a mononuclear [Ti(L)(OCH 3 )(acac)] complex which crystallizes in the monoclinic space group P2 1 /c, a = 18.2786(13), b = 8.2609(5), c = 13.9008(10) Å , β = 96.809(3)° with Z = 4. Cyclic voltammetric experiments of the species in acetonitrile solution reveals a reversible peak at E o´ = −0.768 V (vs. Ag/AgCl) relating to the Ti IV /Ti III redox process. Graphical Abstract Synthesis, Crystal Structure and Electrochemical Studies of a Hydrazone Schiff Base Complex of Titanium(IV)

Tetrahydro-1H-benzo[b]azonin-2,7-dione (2a) has been used as a precursor in the synthesis of dibenzo[ b,f ][1,5]diazacyclododecene and dibenzo[b,g][1,6]diazacyclododecene ring systems 4 and 5, respectively, via periodate oxidation of the appropriate indolo-benzo[b]azonines 3 and 7. The synthesis of hexahydro-benzo[b][1,4]diazecin-2,7-dione (10) has been achieved by the Schmidt reaction of 2a. The periodate oxidation of 9,9´-methylenebis(2,3,4,9-tetrahydro-1H-carbazole) (11) afforded 1,1´- methylenebis(3,4,5,6-tetrahydro-1H-benzo[b]azonin-2,7-dione) (12). Its 6,6´-methylenebis isomer 13 was obtained by treating 2a with formaldehyde. Oxidation of 16 gave the unsymmetrical bi(benzo [b]azonine) 17. The Mannich reaction of 2a led to a mixture of its 6-methylene derivative 19 and the spirocyclic system 20. The reactions of 2a with aldimines and aromatic aldehydes were also investigated. Graphical Abstract Key words: Titanium(IV), Hydrazone, Schiff Base, Molecular Structure, Cyclic Voltammetry

Three new CF 3 -substituted bicyclic salicylate derivatives were synthesized by the TiCl 4 -mediated cyclization of trifluoromethyl-containing ketones with 1,3-bis(silyl enol ethers) and characterized by NMR and IR, spectroscopy, mass spectrometry and elemental analysis. The crystal structures of the bicyclic derivatives have been determined by single crystal X-ray analysis. All structures exhibit hydrogen bonding. Graphical Abstract NMR Studies and Crystal Structure Determinations of CF 3 Group-containing Bicyclic Phenolates

The triethyloxonium tetrafluoroborate/1,2-dimethoxyethane (TEO/DME) mixture is a versatile and cheap substitute for trimethyloxonium tetrafluoroborate in O-methylations of pyrrolin-2-ones, quinolones, acridones, and 1-oxo-β -carbolines. Undesired O-ethylation can be avoided by preincubation of triethyloxonium tetrafluoroborate and 1,2-dimethoxyethane for 1 h, prior to addition of the substrate. In the course of these investigations it was found that the structures assigned to the alkaloids taraxacine A and B are erroneous. Graphical Abstract Triethyloxonium Tetrafluoroborate/1,2-Dimethoxyethane – a Versatile Substitute for Trimethyloxonium Tetrafluoroborate in O-Methylation Reactions

Pyridine and quinoline react with 3-bromoacetyl-1,5-diphenyl-1H-pyrazole-4-carbonitrile (2) in dry benzene to give the corresponding pyridinium and quinolinium salts 3 and 9. The latter salts undergo [3+2] 1,3-dipolar cycloaddition with some acetylene and ethylene derivatives to give the corresponding indolizine and pyrrolo[1,2-a]quinoline derivatives Graphical Abstract Synthesis of Some New Indolizine and Pyrrolo[1,2-a]quinoline Derivatives via Nitrogen Ylides

A new anti-inflammatory spirovetivane-type sesquiterpenoid, designated as 1,10-didehydrolubimin (1) and thirteen known compounds (2 - 14) were isolated from the whole plants of the ‘Yi’ ethnomedicinal plant Incarvillea arguta. Their structures were established based on spectral methods and by comparison of the spectral data with those reported previously. Compound 1 exhibited significant inhibitory effects on Cox-1 and Cox-2 and a negative effect against 5-Lox at the concentration of 100 μM. Graphical Abstract A New Cyclooxygenase Inhibitor from Incarvillea arguta

Two new clerodane-type diterpenoids, along with seven known compounds have been isolated from the aerial parts of Gomphostemma microdon. All structures were established on the basis of spectroscopic analyses, including application of MS, UV, IR, 1D and 2D NMR techniques. Graphical Abstract Two New Clerodane-type Diterpenoids from Gomphostemma microdon

The cytotoxicity of the methanol extract of Origanum syriacum against human cerivical adenocarcinoma, Hela cells, was evaluated by the MTT assay. From the crude extract, a new flavone glycoside, acacetin-7-O-[2´´-O-α-L-rhamnopyranosyl-6´´-O-β -D-glucopyranosyl]-β -D-glucopyranoside (1), together with the ten known flavonoids luteolin (2), apigenin (3), luteolin-6-C-glucoside (4), luteolin-3´-methylether-6-C-glucoside (5), luteolin-7,4´-dimethyether-6-C-glucoside (6), apigenin-7- methylether-6-C-glucoside (7), apigenin-7-O-glucoside (8), diosmetin-7-O-glucoside (9), acacetin- 7-O-glucoside (10) and acacetin-7-O-rutinoside (11), was isolated from the methanol extract of the aerial parts of Origanum syriacum. The structure elucidation of the isolated compounds was performed by spectroscopic and chromatographic methods. Graphical Abstract Phytochemical Constituents and Biological Activities of Origanum syriacum

Two new phenylethanoids, basalethanoid A (1) and B (2), and one new ceramide, basalamide A (3), together with eleven known compounds (4 - 14) were isolated from theMeOH extract of the stem barks of Basalmocitrus cameroonensis. The structures of all compounds were determined by comprehensive analyses of their 1D and 2D NMR, mass spectral (EI and ESI) data, chemical reactions, and comparison with previously known analogs. Compounds 1, 2, 5, and 7 - 10 demonstrated a strong inhibition on reactive oxygen species (ROS) production in the oxidative burst activity of whole blood on activation with serum opsonized zymosan in the range of IC 50 = 0.06 - 12.30 μg mL −1 . Graphical Abstract Bioactive Phenylethanoids and Coumarines from Basalmocitrus cameroonensis

Aerial parts of Skimmia laureola yielded a new (+)-lanostane-3β ,24-dihydroxy-25-ene triterpene (1) along with fourteen known compounds. The structures were identified by spectroscopic studies Graphical Abstract A New Lanostane Triterpene from Skimmia laureola

The first total synthesis of galloyl tyramine, an inhibitor of Pim2 kinase was accomplished in an overall high-yield reaction sequence Graphical Abstract The First Total Synthesis of Galloyl Tyramine

The first triorganosulfonium azides [Me 3 S]N 3 and [Ph 3 S]N 3 were prepared by reaction of the corresponding sulfonium bromides/iodides with silver azide and characterized by spectroscopic methods. The molecular structure of [Ph 3 S]N 3 as well as that of the precursor, [Ph 3 S]Br, have been determined by X-ray diffraction. Graphical Abstract Preparation and Characterization of the First Organosulfonium Azides