ISSN:
1434-1948
Keywords:
Chromium
;
Carboxylate complexes
;
Metal-metal multiple bonds
;
Molybdenum
;
Rhenium
;
Tungsten
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Reaction of Re2{μ-O2CC(CH3)3}4Cl2 with [(CO)5M-CN]Na (M = Cr, Mo, W) leads to tetranuclear complexes of formula Re2{μ-O2CC(CH3)3}4[-NC-M(CO)5]2 (M = Cr, Mo, W). These complexes were characterized by 1H-, 13C-, and 95Mo-NMR, IR and Raman spectroscopy, elemental analysis and examined by cyclic voltammetry. The applied methods show the donor capabilities of the [(CO)5M-CN]- ligands which shift electron density towards the Re centers weakening the Re-Re quadruple bond. The Re-Re bond lengths and the ν(Re-Re) force constants are estimated based on the FT-IR and Raman examinations. Photochemical examinations and TG/MS experiments have also been conducted. The latter method shows that the product complexes decompose around 100 °C, by first loosing their carbonyl substituents; as do the Cr, Mo, W precursor compounds. The dirhenium tetrapivalate unit decomposes only at higher temperatures in a distinct second step.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
