Bis(6-Diphenylphosphinoacenaphth-5-yl)Telluride as a Ligand toward Manganese and Rhenium Carbonyls.

The reaction of the previously known bis(6-diphenylphosphinoacenaphthyl-5-)telluride (6-Ph₂P-Ace-5-)₂Te (IV) with (CO)₠ReCl and (CO)₠MnBr proceeded with the liberation of CO and provided fac-(6-Ph₂P-Ace-5-)₂TeM(X)(CO)₃ (fac-1: M = Re, X = Cl; fac-2: M = Mn, X = Br), in which IV acts as bidentate ligand. In solution, fac-1 and fac-2 are engaged in a reversible equilibrium with mer-(6-Ph₂P-Ace-5-)₂TeM(X)(CO)₃ (mer-1: M = Re, X = Cl; mer-2: M = Mn, X = Br). Unlike fac-1, fac-2 is prone to release another equivalent of CO to give (6-Ph₂P-Ace-5-)₂TeMn(Br)(CO)₂ (3), in which IV serves as tridentate ligand.