Determination of rhenium: chlorine ratios in complexes by neutron activation

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One of a series of compounds obtained by the reaction of chloropentacarbonylrhenium (1) with [3-diketones has been shown by single crystal X-ray diffraction to be bis(p-0-1,3-diphenylpropane-1,3-dionatotricarbonylrhenium(1)f. The crystals are monoclinic with lattice parameters a = 11.988(A) A, b = 14.441(9) A, c = 10.298(7) A, = 115.25(7)'. The space group is PZ,!c and there are two dimers per unit cell. A total of 1563 independent reflections were measured on a single crystal X-ray diffractometer and the structure was refined by least squares analysis to a weighted R, value of 0.0427. The dimer units are held together by two bridging oxygen atoms, one from each of the a-ketoenolate groups; the distance of the bridging oxygen from the rhenium atom to which it is chelated (2.162(9) A) is shorter than the distance to the other rhenium atom (2.204(7) A). The main part of the B-ketoenolate ring is 37" from the OReO plane.L'un des coinposCs obtenu par la reaction du chloropentacarbonylrheni~~n~(I) sur les a-dicetones a CtC identifie par diffraction aux rayons X sur un monocristal au bis (fi-0-diphenyl-I ,3-propanedionato-1,3 tricarbonylrhenium(1)). Ees cristaux sont monocliniques, les parametres du reseau sont: a = 11.988 A, b = 14.441(9) A, c = 10.298(7) A, [3 = 115.25(7)'. Le groupe spatial est P2,lc et il y a deux dimeres par maille. Un total de 1563 reflexions independantes a ete mesure au diffractometre aux rayons X sur un monocristal, la structure a Cte raffinee par la methode des moindres carrCs jusqu'a obtention d'une valeur ponderee sur R, de 0.0427. Les dimeres dans la maille sont relies entre eux par deux atomes d'oxygeile formant un pont, chacun d'eux provenant des groupes p-~Ctoenolates; la distance de I'oxygene pont B l'atome de rl~kniun~ auquel il est chelate (2.162(9) A) est plus courte que celle qui le separe de

Section: Methodsmentioning

confidence: 99%

Studies of Rhenium β-Diketone Complexes. III. The Crystal and Molecular Structure of Bis(μ-O-1,3-diphenylpropane-1,3-dionatotricarbonylrhenium(I))

Barrick¹,

Fredette²,

Lock³

1973

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“…Rhenium and chlorine analyses were performed by the neutron activation method described previously (5). Infrared spectra were recorded for solid samples ground into a mull with Nujol.…”

Section: Methodsmentioning

confidence: 99%

Oxodichlororhenium(IV), ReOCl₂

Frais¹,

Howard-Lock²,

Lock³

1973

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The preparation and some physical and chemical properties of ReOCI, are described.On dCcrit la prkparation ainsi que quelques propri Can. J Chem . 51. 828 (1973) Introduction Until recently only two oxochlorides of rhenium have been clearly established, namely ReOCl, and Re03Cl (1). Very recently there have been reports of ReOCI, (2) and the mixed complexes Re03Cl-ReOCl, (3) and Re,03C1,-(ReO,Cl), (4). We now report the existence of yet another simple oxochloride, namely oxodichlororhenium(IV), ReOCI,. ExperimentsRhenium and chlorine analyses were performed by the neutron activation method described previously (5). Infrared spectra were recorded for solid samples ground into a mull with Nujol. The Nujol had been dried by refluxing with phosphorus pentoxide followed by vacuum distillation. The mull samples were mounted between potassium bromide plates and spectra were recorded on Perkin-Elmer 337, 521, and 301 spectrometers. Raman emission was excited by 10 mW of radiation from a He-Ne laser 0,6328 A), and spectra were recorded with a Coderg PHO double monochromator with photoelectric detection. X-Ray diffraction photographs of powdered samples were recorded on a Debye-Scherrer camera. Samples were sealed inside fused quartz tubes and nickel-filtered CuKcc radiation was used for recording the photographs. Line intensities were measured from the photographs with a Joyce-Loebl microdensitometer. ReOC12 was prepared by a number of different chemical reactions. Typical reaction conditions are described below unless changes in the conditions made significant differences in the distribution of products, in which case different runs are described. Analysi~ and Identification of Prod~lctsFor qualitative identification of products only infrared spectroscopy (volatile materials) or X-ray diffraction (involatile n~aterials) was used. Combination of these techniques with quantitative analysis (see below) applied to pure and known "impure" samples (i.e. mixtures of known composition) has shown that infrared spectroscopy could identify as little as 5% of an impurity (and in many cases < 1%) while X-ray diffraction could detect as little as 5% of impurity in a single substance and 10% in a ' T o whom correspondence should be addressed.CtCs physiques et chimiques de ReOC1,.[Traduit par le journal] mixture of two compounds. For X-ray diffraction it is possible that large quantities of an amorphous product were present but we have no other evidence for this in any of our experiments. For each type of reaction reported below many runs were made (typically 5-10) and in most runs attempts were made not only to separate volatile and involatile products, but to separate the products into individual components. This was hard to do for volatile products, but for involatile products was achieved by hand-picking crystals. Parts of both volatile and involatile samples were examined by X-ray and infrared techniques to confirm that only the expected products were present. For quantitative analysis of a reaction, the nature of the products ...

“…Analyses for rhenium and chlorine, as well as determination oftheoxidation stateofrhenium by thealkalinehydrolysis method were performed using the neutron activation method described previously (2). Infrared spectra were recorded on Perkin-Elmer 337 and 521 spectrometers.…”

Section: Methodsmentioning

confidence: 99%

“…Nevertheless, it was possible to isolate several single crystals and do a single crystal X-ray structure analysis. The only other chemical experiment done on these crystals was neutron activation analysis (2). The combined results showed a molecular compound containing a rhenium atom, four chlorine atoms, and two other light atoms, probably oxygen atoms.…”

Section: Introductionmentioning

confidence: 99%

The Preparation, Physical Properties, and Structure of Oxotetrachloroaquorhenium(VI), ReOCl₄(OH₂)

Frais¹,

Lock²

1972

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Oxotetrachloroaquorhenium(VI), ReOC1,-H,O, has been prepared and characterized for the first time by analysis, infrared spectroscopy and single crystal X-ray diffraction. The crystals were orthorhombic, a = 10.834(8), b = 11.089(8), c = 5.51 7(4) A, Pn2,a, Z = 4. Intensity data were recorded by integrating film methods and measured with a Joyce-Loebl microdensitometer, and 624 observable of the 704 measured independent reflections were given non-zero weight in the final cycle of full matrix least-squares refinement where R, = 0.0572 and R, = 0.0687., The molecular structure is based on a very distorted octahedron with a stron ly