21 research outputs found
Bis(η6-naphthalene)Âmolybdenum(0)
The title compound, [Mo(C10H8)2], was prepared from the naphthalene radical anion and MoCl4(thf)2 (thf is tetraÂhydroÂfuran). In the crystal, the molÂecule is located on an inversion center. The Mo atom is equally disordered over two positions; the range of Mo—C distances is 2.2244 (19)–2.3400 (17) Å for both components of the disorder
Bis{bis[1-methoxy-2-(2-methoxyethoxy)ethane-κ3O,O′,O′′]sodium} 1,1,2,2-tetraphenylethane-1,2-diide
Crystals of the title salt, [Na(C6H14O3)2]2(C26H20), were grown from a tetrahydrofuran/diglyme/Et2O solvent mixture [diglyme is 1-methoxy-2-(2-methoxyethoxy)ethane]. The cations and dianion are separated in the crystal structure, unlike in the other three structurally characterized dialkali metal tetraphenylethylene salts. The asymmetric unit contains one [Na(diglyme)2]+ cation and one half of the [Ph2CCPh2]2− dianion. The latter lies on a twofold rotation axis. C—C bond-length redistribution displays that excessive electron density of the dianion is predominantly located at the C atoms of a former double bond and at all eight ortho positions. The studied crystal was a twin, with the ratio of two major components being 0.2143 (9):0.7857 (9). The twin operation is a twofold rotation around the a axis
Crystal structure of heptakis(2,6-dimethylphenyl isocyanide-κC)vanadium(I) iodide
The title salt, [V(C9H9N)7]+I− or [V(CNXyl)7]+I− (Xyl is 2,6-dimethylphenyl), crystallized from tetrahydrofuran at low temperatures after reacting (Et4N)+[V(CO)6]−, excess of CNXyl and iodine. The complex cation and the two crystallographically different iodide anions, each located on a different glide plane, are well separated in the crystal structure. The V(CN)7 core of the cation has the form of a distorted monocapped trigonal prism. This compound is of interest as the first isolable homoleptic seven-coordinate vanadium analog of the 18-electron [V(CO)7]+ monocation
Crystal structure of bis(μ2-triphenylacetato-κO:κO′)bis(diisobutylaluminium)
Single crystals of the title compound, [Al(iBu)2(O2CCPh3)]2 or [Al2(C4H9)4(C20H15O2)2], have been formed in the reaction between tris(tetrahydrofuran)tris(triphenylacetato)neodymium, [Nd(Ph3CCOO)3(THF)3], and triisobutylaluminium, Al(iBu)3, in hexane followed by low-temperature crystallization (243 K) from the reaction mixture. The structure has triclinic (P\overline{1}) symmetry at 120 K. The dimeric complex [Al(iBu)2(O2CCPh3-μ-κO:κO′)]2 is located about an inversion centre. The triphenylacetate ligand displays a μ-κO:κO′-bridging coordination mode, leading to the formation of an octagonal Al2O4C2 core. The complex displays HPh...CPh intermolecular interactions
Straightforward and Efficient Protocol for the Synthesis of Pyrazolo [4,3-<i>b</i>]pyridines and Indazoles
An efficient method for the synthesis of pyrazolo [4,3-b]pyridines has been developed on the basis of readily available 2-chloro-3-nitropyridines via a sequence of SNAr and modified Japp–Klingemann reactions. The method offers a number of advantages including utilization of stable arenediazonium tosylates, operational simplicity as well as combining the azo-coupling, deacylation and pyrazole ring annulation steps in a one-pot manner. An unusual rearrangement (C-N-migration of the acetyl group) was observed and a plausible mechanism was proposed based on the isolated intermediates and NMR experiments. In addition, the developed protocol was successfully applied to the synthesis of 1-arylindazoles combining the Japp–Klingemann reaction and cyclization of the resulting hydrazone as a one-pot procedure
Nucleophilic Functionalization of 2-R-3-Nitropyridines as a Versatile Approach to Novel Fluorescent Molecules
A number of new 2-methyl- and 2-arylvinyl-3-nitropyridines were synthesized and their reactions with thiols were studied. It was found that 3-NO2 tends to be selectively substituted under the action of sulfur nucleophiles in the presence of another nucleofuge in position 5. Correlations between the substitution pattern and regioselectivity as well as photophysical properties were established. Some synthesized compounds possessed a large Stokes shift
Crystal structure and catalytic activity of tetrakis(μ2-ethyl 2,6-di-tert-butyl-4-methylphenyl phosphato-κ2O:O′)bis(ethyl 2,6-di-tert-butyl-4-methylphenyl phosphato-κ2O,O′)dilutetium n-heptane disolvate
The title complex, [Lu2(C17H28O4P)6]·2C7H16, was formed in the reaction between potassium 2,6-di-tert-butyl-4-methylphenyl ethyl phosphate, [K(2,6-tBu2-4-MeC6H2-O)(EtO)PO2], and LuCl3(H2O)6 in water, followed by vacuum drying and recrystallization from heptane. Its crystal structure has triclinic (P\overline{1}) symmetry at 120 K. The lutetium tris(phosphate) complex has a binuclear [Lu2(μ-OPO)4] core and the organophosphate ligand exhibits κ2O,O′ terminal and μ2-κ1O:κ1O′ bridging coordination modes with the LuIII ion being sixfold coordinated. The complex is of interest as a precatalyst in the acrylonitrile polymerization process and displays good catalytic activity under mild conditions
Crystal structure of bis(μ2-methanolato-κO:κO)hexamethylbis(μ2-triphenylacetato-κO:κO′)bis(μ2-triphenylacetato-κ2O,O′:κO)dialuminiumdilanthanum toluene tetrasolvate
The title compound, [Al2La2(C20H15O2)4(CH3)6(CH3O)2]·4CH3C6H5 or [{La(Ph3CCOO)2(Me3AlOMe)}2]·4CH3C6H5, was formed in a reaction between lanthanum tris(tetramethylaluminate) and triphenylacetic acid (1:1) with unintended partial oxidation. The triphenylacetate ligand exhibits μ2-κ1O:κ1O′ bridging and μ2-κ2O,O′:κ1O semi-bridging coordination modes, forming a dimeric La2(μ-OCO)4 core. The semi-bridging triphenylacetate group provides additional bonding with an La3+ cation via the π-system of one of its phenyl rings. The trimethylmethoxyaluminate anion, which is coordinated to the La3+ cation by its O atom, displays a rather long La—CMe bond. Two toluene molecules are each disordered over two orientations about centres of symmetry with site occupancy factors of 0.5. The title compound represents the first example of an LnIII complex containing both alkyl alkoxide aluminate and π-bounded arene fragments
Synthesis, characterization and redox properties of Ar-C=N -> Ge <- N=C-Ar containing system
International audienceNew Schiff base germanate derivative containing the chain Ar-C=N -> Ge <- N=C-Ar was synthesized and characterized by physical methods including X-ray diffraction. The stability of the corresponding radical anion obtained electrochemically was confirmed by cyclic voltammetry, the results were compared with UV-VIS data and quantum chemical calculations