1,3,5-Trimethyl-1,3,5-triazacyclohexane tricarbonyl complexes of Mo and W as sources of the fac-M(CO)3 fragment. Mild syntheses of fac-[M(CO)3(CH3CN)3] (M=Mo, W), [W(CO)3(PR3)3], [W(CO)(alkyne)3] and [W(CO)3(π-arene)] complexes

Abstract The 1,3,5-trimethyl-1,3,5-triazacyclohexane (Me 3 tach) group in [M(CO) 3 (Me 3 tach)] complexes (M=Mo, W) is easily displaced by a variety of ligands under mild conditions. The lability of the Me 3 tach ligand allows the [M(CO) 3 (Me 3 tach)] complexes to be used as synthetic intermediates in convenient syntheses of products such as fac -[M(CO) 3 (CH 3 CN) 3 ] (M=Mo, W), [W(CO)(alkyne) 3 ], [W(CO) 3 (PR3) 3 ] and [W(CO) 3 ( η 6 -arene)] complexes. An improved synthesis of [W(CO) 3 (Me 3 tach)] from [W(CO) 6 ] and Me 3 tach is described.