Metal carbonyls of telluroether formed by the oxygen atom transfer reaction to M(CO)6 (M = Mo, W) in the presence of (p-CH3OC6H4)2TeO and relative kinetic investigation

Abstract A new synthetic process is reported for the preparation of two substituted metal carbonyls, ( p -CH 3 OC 6 H 4 ) 2 TeM(CO) 5 (M = Mo, W). In the presence of ( p -CH 3 OC 6 H 4 ) 2 TeO as O atom transfer reagent in tetrahydrofuran solvent, a CO ligand is replaced by telluroether when M(CO) 6 (M = Mo, W) is reacted with ( p -CH 3 OC 6 H 4 ) 2 TeO under very mild experimental conditions (r.t.). The products were characterized by elemental analysis, mass, IR and 1 H NMR spectroscopies. The spectra suggest that the coordination geometry is distorted from a regular octahedral structure due to an asymmetrical bulky telluroether ligand on the metal atom. Kinetics of these reactions of M(CO) 6 with ( p -CH 3 OC 6 H 4 ) 2 TeO show the reactions are first order in the concentration of M(CO) 6 and of Te oxide. The rates of reaction decrease in the order W(CO) 6 >Mo(CO) 6 >Cr(CO) 6 , and the results obtained are discussed in term of a presumed mechanism.