Search results for "Organometallic Chemistry"

ChemInform Abstract: Unique Reactivity of Fluorinated Molecules with Transition Metals

2015

Organofluorine and organometallic chemistry by themselves constitute two potent areas in organic synthesis. Thus, the combination of both offers many chemical possibilities and represents a powerful tool for the design and development of new synthetic methodologies leading to diverse molecular structures in an efficient manner. Given the importance of the selective introduction of fluorine atoms into organic molecules and the effectiveness of transition metals in C-C and C-heteroatom bond formation, this review represents an interesting read for this aim.

Coordinating behaviour of a new pyridylhydrazone; tris-complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with 2-pyridylcarb…

1991

The preparation and characterization oftris-complexes of MnII, CoII, NiII, CuII and ZnII with a new pyridylhydrazone, 2-pyridylcarbaldehyde-N,N-dimethylhydrazone (pch), are described. In all the complexes pch behaves as a bidentate ligand binding through the pyridine and azomethyne nitrogen atoms. The complexes appear to be monomeric, high spin six-coordinate, and a distorted octahedral stereochemistry around the metal is suggested. The e.p.r. results for both CuII compounds indicate a mainly dx2−y2 ground state with a static Jahn-Teller distortion, whilst for the MnII complex the e.p.r. data indicates a very low symmetry for the MnN6 polyhedron.

Chemistry of ?-hydridobis[pentacarbonylchromium(0)] species. Part III. Redox reactions with mercury(II) compounds and iodine

1981

[Cr2(CO)10(μ-H)]− undergoes ready hydride substitution on reaction with HgX2 (X = Cl, Br, I or SCN) or with iodine in acetone, yielding [Cr2(CO)10(μ-X)]− complex species which can be converted quantitatively into [Cr(CO)5X]− anions by reactions conducted in the presence of an excess of X−.

The first example of cofacial bis(dipyrrins)

2016

International audience; Two series of cofacial bis(dipyrrins) were prepared and their photophysical properties as well as their bimolecular fluorescence quenching with C-60 were investigated. DFT and TDDFT computations were also performed as a modeling tool to address the nature of the fluorescence state and the possible inter-chromophore interactions. Clearly, there is no evidence for such interactions and the bimolecular quenching of fluorescence, in comparison with mono-dipyrrins, indicates that C-60-bis(dipyrrin) contacts occur from the outside of the "mouth" of the cofacial structure.

Titanium Complexes Stabilized by a Sulfur‐Bridged Chelating Bis(aryloxo) Ligand as Active Catalysts for Olefin Polymerization

2004

The mixed-ligand complexes [Ti2(μ-OR)2(OR)2(κ3-tbop)2] (1a) for R = Me and (1b) R = Et were prepared by the reaction of Ti(OR)4 and H2tbop {H2tbop = 2,2′-thiobis[4-(1,1,3,3-tetramethylbutyl)phenol]} in methanol. Treatment of 1a and 1b with AlMe3 led to the substitution of terminal alkoxy groups to create the organometallic compounds [Ti2(μ-OR)2(κ3-tbop)2(Me)2] (2a) for R = Me and (2b) for R = Et. Controlled hydrolysis of 2b causes the evolution of methane and the formation of the titanoxane compounds [{Ti2(μ-OEt)2(κ3-tbop)2}2(μ-O)2]·2CH2Cl2 (3). Structures of 1a, 1b, 2a, 2b, and 3 were confirmed by NMR spectroscopy; 1b and 3 were further investigated with X-ray crystallography. Compounds 1a…

Book Review: Applied Homogeneous Catalysis with Organometallic Compounds. Vols. 1–3. 2nd. Edition. Edited by Boy Cornils and Wolfgang A. Herrmann

2002

Preparative and spectroscopic features of ferricenium tetrachloroferrate(III). Interconversion to diferricenium ?-oxo-bis[trichloroferrate(III)]

1985

Ferricenium tetrachloroferrate(III)(1), one of the more frequently cited ferricenium salts, has recently attracted biomedical interest because of its pronounced antineoplastic activity against Ehrlich ascites murine tumor. In this paper, synthetic methods are reinvestigated in an effort to prepare pure(1) free from a common contaminant, diferriceniumμ-oxo-bis(trichloroferrate)(3). The oxodiferrate, or mixtures of this salt with(1), can readily be converted into pure(1) under acidic conditions. Conversely, dimerization of(1) with participation of water to give the oxodiferrate(3) is brought about by recrystallization of the former from moist acetonitrile/methanol in the presence of base; thi…

Use of a reduced Schiff-Base ligand to prepare novel chloro-bridged chains of rare Cu(II) trinuclear complexes with mixed azido/oxo and chloro/oxo br…

2010

Two mixed bridged one-dimensional (1D) polynuclear complexes, [Cu(3)L(2)(mu(1,1)-N(3))(2)(mu-Cl)Cl](n) (1) and {[Cu(3)L(2)(mu-Cl)(3)Cl].0.46CH(3)OH}(n) (2), have been synthesized using the tridentate reduced Schiff-base ligand HL (2-[(2-dimethylamino-ethylamino)-methyl]-phenol). The complexes have been characterized by X-ray structural analyses and variable-temperature magnetic susceptibility measurements. In both complexes the basic trinuclear angular units are joined together by weak chloro bridges to form a 1D chain. The trinuclear structure of 1 is composed of two terminal square planar [Cu(L)(mu(1,1)-N(3))] units connected by a central Cu(II) atom through bridging nitrogen atoms of end…

Compounds of molybdenum(VI) with aspartic acid: A spectrophotometric and potentiometric study of the formation and interconversion equilibria in aque…

1990

Addition of Na2MoO4 to an excess of aspartic acid (AspH2) can produce any of four different complexes depending on the pH, namely [MoO3(Asp)]2−, [Mo2O5(Asp)2]2−, [Mo2O4(OH)(Asp)2]− and [Mo2O4(Asp)2]. The ranges of formation of these species with pH, the number of equivalents of acid necessary for their formation, and their stoichiometries, condensation degrees and stability constants, have been calculated by potentiometric and spectrophotometric techniques. The aspartic acid acts as a tridentate ligand in all cases.

Bridging vs. Chelating Coordination Modes of Vinylsilanes in CuIπ-Complexes: Structure and Stability

2013

Two new copper(I) olefin complexes, [Cu6Cl6(MTrVS)2] (1) and [Cu2Cl2(DMVSP)2] (2), of tridentate bridging methyltrivinylsilane (MTrVS) and bidentate chelating 2-[dimethyl(vinyl)silyl]pyridine (DMVSP) have been synthesized and characterized by single-crystal X-ray structure analysis, IR and 1H NMR spectroscopy. It has been shown that using the alkenylsilanes with required electronic properties, molecular symmetry and conformational flexibility, it is possible to control the formation of optimal copper(I) halide oligomers. The obtained results, together with relevant literature data, also illustrate how the coordination mode of vinylsilanes is related to Cu–(C=C) bond strengthening and, conse…