Carbonyl-π-allyl complexes of molybdenum and tungsten

Abstract

Allyl halides and 2-methyllaly halides react with the substituted carbonyls Mo(CO) 4(Bipy) and Mo(CO) 4(Phen), (Bipy = 2,2′-bipyridyl and Phen = 1,10-phenanthroline), in boiling tetrahydrofan to yield derivatives of the type Mo(CO) 2(Bipy)(π-allyl)X and Mo(CO) 2(Phen)(π-allyl)X,(X = Cl, Br, or I). Identical products result respectively form reaction of the compounds Mo(CO) 3(Bipy)(Py) and Mo(CO) 3(Phen)(Py), (Py = pyridine), with ally halides. Good yields of the tungsten π-allyl compounds can be obtained only by the latter route. Replacement of the chloride in the molybdenum and tungsten compounds may be effects readily by other anions (SCN p− or SC 6F p− 5) or by pyridine in the presence BF p− 4 or BPH p− 4. The existence of the π-allyl system in the thiocynates and salt-like compounds has been demonstrated by PMR measurements in liquid SO 2.