Structural aspects of copper pyrazolato complexes

in "The Chemistry of the Copper and Zinc Triads

Sintesi, caratterizzazione ed impieghi del nuovo composto ottamerico di rame bivalente di formula [Cu8(OH)8(3,5-dimetilpirazolato)8].

Brevetto Nazionale depositato il 22 Giugno 199

COS trapping by palladium pyrazolates: addition vs. clathration

[Pd(dmpz)(2)(Hdmpz)(2)(2)] (Hdmpz = 3,5-dimethylpyrazole) reacts with COS, both in solution and in the solid state, affording [PdSC(O)dmpz(2)] and [Pd(dmpz)(2)(Hdmpz)(2)2]. COS, respectively; the structure of the latter is determined by ab initio methods from conventional X-ray powder diffraction data only

Powder route to crystal structures: X-ray powder diffraction determination of polymeric silver imidazolate

Silver imidazolate has been synthesized and its solid-state structure determined, ab initio. from conventional X-ray powder diffraction data only. The crystals are orthorhombic, space group P2(1)2(1)2(1), with a = 5.5759(4), b = 6.7452(4), c = 22.174(1) Angstrom, U = 834.0(1) Angstrom>(3), Z = 8, D-c = 2.786 g cm(-3). The structure was solved by a real-space scavenger technique and refined by the Rietveld method down to R(p) and R(F) values of 0.062 and 0.027, respectively, for 4401 data points (1262 reflections) measured at room temperature in the 17-105 degrees (2 theta) range. The crystal structure of [Ag(im)(n)] (Him = imidazole) consists of a complex packing of polymeric chains folding about the crystallographic c axis, containing linearly co-ordinated silver atoms joined by imidazolate fragments. Short interchain Ag ... Ag contacts [3.161(4) Angstrom] were observed

A Re(I)-Re(VII) complex by the oxygenation reactions of Re(I) species. Reactivity and X-ray structural characterization of [Re(CO)3(PPh3)2(OReO3)].

The hydrido complex HRe(CO)2(PPh3)3 reacts with tertiary amines, in the presence of O2 and H2O, to give Re(CO)2(PPh3)2(O2CR), containing a chelating carboxylato group originated by oxidation of the alkyl group of the amine. NEt3, N(n-Pr)3 and N(n-Bu)3 have been used, the acetato, propionato and butyrato derivatives being respectively obtained. In the absence of the amine, the reaction gives the Re(I)-Re(VII) complex Re(CO)3(PPh3)2(OReO3), 1, containing a coordinated perrhenate ion. The same species was obtained by reaction of Re(CO)3(PPh3)2(NHCOC6H4Me) with O2/H2O. Complex 1 has been alternatively prepared by reacting ReCl(CO)3(PPh3)2 with AgReO4. Crystals of 1 have been shown by single crystal X-ray analysis to be monoclinic, space group P2(1)/n (No. 14 with a = 10.248(6), b = 27.487(5), c = 13.247(2)angstrom, beta = 97.55(2)-degrees and Z = 4. The refinement performed by full-matrix least-squares methods, for 4651 independent significant reflections, gave a final R value of 0.029. The crystals contain discrete dinuclear molecules with an octahedrally coordinated Re(I) atom bearing three carbonyls, two mutually trans triphenylphosphine ligands and a coordinated ReO4- moiety. Complex 1 was shown to be partially dissociated in acetone solution and the value of the dissociation constant has been estimated by means of the Ostwald relationship [K = 6(1)x10(-5)]. The addition Of NEt3 to an acetone solution of 1 at room temperature causes its complete dissociation. Complete dissociation was also observed in acetonitrile, with formation of the ionic species [Re(CO)3(PPh3)2-(MeCN)][ReO4], 2. Complex 1 reacts with NEt3, at 55-degrees-C under an inert atmosphere, to give the rhenium(I) acetato derivative Re(CO)2(PPh3)2(O2CCH3), showing that the perrhenate anion is able to perform the oxidation of alkyl groups of tertiary amines to carboxylato groups