1,2-Bis(triazolyl)tetraphenyldigermanes: Synthesis, Structure and Properties.

Using the [3+2] cycloaddition reaction of [HC≡C-GePh -] (1) and a number of RCH N , this work described the synthesis of a series of novel heterocyclic digermanes, bitriazoles [1,4-C HN (CH R)GePh -] , 2-12 (R=Ph, p-Tol, p-C H NMe , p-C H OMe, p-C H Br, m-C H NO , 2-Naphth, CH -p-OC H CHO, CH -p-OC H COOMe, CH P(O)(OEt) , COOEt), difficult to produce by other methods. The structural peculiarities of these compounds were studied in detail by NMR spectroscopy and by XRD analysis (for 6, 9 and 10). The properties of 1-12 were studied by UV/vis and luminescence emission spectroscopy, electrochemistry and DFT calculations, indicating an effective conjugation in their molecules.

Structural Motifs in Aryl Organogermanium Ge-O Derivatives for Material Design.

The aim of this work was to understand the main structural features and ways of formation of Ge-O bonds in organogermanium compounds under the conditions of ArGeHal (Hal = halide) hydrolysis. The structural types of these compounds were considered, providing 11 blocks (-). The molecular structures of the novel compounds [(-FCH)Ge]O (), [(-FCCH)Ge]O (), and -[(-FCCH)GeO] () were studied through XRD (X-ray diffraction) analysis.

Formation of Azaphilone Pigments and Monasnicotinic Acid by the Fungus .

Due to the ever-increasing demand for healthy and safe food, much attention has been gained by natural food colorants. This study showed the culture fluid extract of the fungus VKM F-906 to contain red pigment and monasnicotinic acid (MNA) in predominant amounts. The structure of the pigment corresponded to -cavernamine (red pigment, RP).

DFT Investigation of the η ⇌ η-Inter-ring Haptotropic Rearrangement of the Group 8 Metals Complexes [(graphene)MCp] (M = Fe, Ru, Os).

Metalcyclopentadienyl complexes (MCp) (M = Fe, Ru, Os) bound to the large polyaromatic hydrogenated hydrocarbon (PAH) CH used as a model for pristine graphene have been studied using a density functional theory (DFT) generalized gradient approximation (PBE functional) to reveal their structural features and dynamic behavior. The inter-ring haptotropic rearrangements (IRHRs) for these complexes were shown to occur via two transition states and one intermediate. The energy barriers of the η ⇌ η IRHRs of the (MCp) unit were found to be 30, 27, and 29 kcal/mol for M = Fe, Ru, and Os, respectively.

Austalides V and W, new meroterpenoids from the fungus Aspergillus ustus and their antitumor activities.

Two new austalide meroterpenoids, named austalides V and W (1 and 2), were isolated from the fungus Aspergillus ustus VKM F-4692. Their structures were elucidated by extensive spectroscopic analysis and by comparison with related known compounds. The main structural feature of both compounds is a tetrahydrofuranyl ring (G), a structural fragment, first found in austalides.

Molecular Oligogermanes and Related Compounds: Structure, Optical and Semiconductor Properties.

The optical (UV/Vis absorbance, fluorescence in the solid state and in solution) and semiconducting properties of a number of di- and trigermanes as well as related silicon- and tin-containing germanes, 1-6 ((p-Tol) GeGeMe (1), Ph SnGe(SiMe ) (2), (C F ) GeGePh (3), (p-Tol) GeSiMe SiMe (4), (p-Tol) GeGeMe Ge(p-Tol) (5), (p-Tol) GeSiMe SiMe Ge(p-Tol) (6)) were investigated. Molecular structures of 5 and 6 were studied by X-ray diffraction analysis. All compounds displayed luminescence properties.

Aluminum complexes based on pyridine substituted alcohols: synthesis, structure, and catalytic application in ROP.

A series of substituted pyridine dialcohols (2,6-bis(hydroxyalkyl)pyridines), 1-4, was used for the synthesis of various types of aluminum complexes. Aluminum methyl derivatives, 2-4a, were obtained by the reaction of AlMe3 with the corresponding ligand or transmetallation reactions of germylenes. Aluminum chloride complexes, 3-4b, were obtained by substitution of the Me group under the action of chlorinating agents.

New oligogermane with a five coordinate germanium atom: the preparation of 1-germylgermatrane.

The first example of an oligogermane, N(CH2CH2O)3Ge-Ge(SiMe3)3 (1), containing a hypercoordinate germanium atom was prepared and characterized by various methods (NMR, UV/vis, and X-ray analysis). The electronic structure of compound 1 was investigated via DFT calculations.

DFT study of intramolecular interring η6,η6-haptotropic rearrangements in tricarbonylchromium complexes of 2-aminobiphenyl and 4-aminobiphenyl.

DFT studies have been carried out to investigate the role of nitrogen participation in the interring haptotropic rearrangements of [(η(6)-C6H5)(C6H4-4-NH2)]Cr(CO)3 and [(η(6)-C6H5)(C6H4-2-NH2)]Cr(CO)3. For the para-substituted case, where intramolecular coordination of nitrogen to chromium is not possible, DFT modeling predicts an activation barrier of 32.5 kcal mol(-1), which is in very close agreement with the experimentally determined value of 32.

Palladium complexes with stabilized germylene and stannylene ligands.

The syntheses of novel Pd complexes with germylene and stannylene ligands are reported. [MeN(CH2CH2NC6F5)2Sn]4Pd (2) and [MeN(CH2CPh2O)(CH2CH2O)Ge]4Pd (8) were obtained by different methods including ligand substitution in (Ph3P)4Pd or by the reaction of the free corresponding germylene or stannylene with (Ph3P)2PdCl2 or Pd(OAc)2. Crystal structures of complexes 2, 8 were determined by single crystal X-ray diffraction analysis.

Lariat ethers with fluoroaryl side-arms: a study of CFmetal cation interaction in the complexes of N-(o-fluoroaryl)azacrown ethers.

New lariat ethers, N-(o-fluorophenyl)aza-15-crown-5 (F-A15C5) and N,N'-bis(o-fluorophenyl)diaza-18-crown-6 (F(2)-A(2)18C6), were prepared by the N-arylation of the corresponding azacrown ethers. The interaction of the ligands with metal cations was studied in solution by (1)H and (19)F NMR (in acetone-d(6)) and UV spectroscopy (MeOH) confirming the formation of complexes of F(2)-A(2)18C6 with K(+), Na(+), Ag(+), Ba(2+), Pb(2+) and of F-A15C5 with Na(+) and giving evidence of CFmetal cation interaction. Cation binding constants (beta, evaluated by UV titration method), demonstrate that F-A15C5 and F(2)-A(2)18C6 form more stable complexes than their fluorine-free analogs.