Sulphur dioxide complexes of molybdenum and tungsten

Abstract

The first well authenticated complexes of molybdenum and tungsten containing co-ordinated sulphur dioxide are described. Reaction of the compounds M(CO)3B py, M(CO)3BPPh3, or M(CO)3py3[M = Mo or W; B = 2,2′-bipyridyl (bipy) or 1,10-phenanthroline (phen); py = pyridine] with gaseous sulphur dioxide in dichloromethane leads to derivatives of the type M(CO)3B(SO2) and M(CO)3 py2(SO2). The compounds Mo(CO)3 bipy py, [Mo(CO)2bipy pyπ-allyl]BF4, or Mo(CO)2 bipy(PPh3)2 react in liquid sulphur dioxide to yield the product, Mo(CO)2 bipy(SO2)2. By reaction of the bis(triphenylphosphine) derivatives with gaseous sulphur dioxide, the mixed complexes Mo(CO)2 bipyPPh3(SO2) and Mo(CO)2 phenPPh3(SO2) are formed.