Reduction of Ammonium Pertechnetate and Ammonium Perrhenate with CO: Synthesis of M2(CO)10 (M: Tc, Re) and Crystal and Molecular Structure of the Trinuclear Cyano-Bridged Derivative Re3(CN)3(CO)12

Fausto Calderazzo (1) , Ulderico Mazzi (2) , Guido Pampaloni (1) , Rinaldo Poli (3) , Francesco Tisato (2) , Pier Francesco Zanazzi (4)

1 University of Pisa - Università di Pisa
2 Unipd - Università degli Studi di Padova = University of Padua
3 University of Maryland [College Park]
4 UNIPG - Università degli Studi di Perugia = University of Perugia

The reaction of the tetra-oxo MO4- anions with CO under pressure and at temperatures around 290 °C (Re) or 200 °C (Tc) leads to the corresponding decacarbonyls Re2(CO)10 and Tc2(CO)10, in yields as high as 69% (Re) or almost quantitative (Tc). The ammonium countercation (NH4+) is an essential pre-requisite for the carbonylation of the tetra-oxo anions, although the [N-n-Bu4]+ or the [N-(n-C8H17)4]+ cations led to satisfactory results in the case of ReO4-. The trimeric cyano-complex Re3(CN)3(CO)12 forms as a by-product in the reaction of ReO4-; its crystal and molecular structure was solved by X-ray diffraction methods. Crystal data for C15N3O12Re3, MW 972.9: orthorhombic; space group Pna21; a = 20.639(3), b = 6.705(3), c = 16.657(3) Å, V = 2305(1) Å3; Z = 4; Dc = 2.802 g cm-3; μ (Mo-Kα) = 159.7 cm-1; Rw = 0.036. The molecular structure consists of a cyano-bridged trimer, the rhenium atom being in a pseudo-octahedral coordination of four carbonyl groups, the other two coordination sites being occupied by atoms from bridging cyano groups.

Domaines: Chimie de coordination; Cristallographie

Fausto Calderazzo, Ulderico Mazzi, Guido Pampaloni, Rinaldo Poli, Francesco Tisato, et al.. Reduction of Ammonium Pertechnetate and Ammonium Perrhenate with CO: Synthesis of M2(CO)10 (M: Tc, Re) and Crystal and Molecular Structure of the Trinuclear Cyano-Bridged Derivative Re3(CN)3(CO)12. Gazzetta Chimica Italiana, 1989, 119, pp.241-247. ⟨hal-03544561⟩