SYMMETRISCH SUBSTITUIERTE BUTADIINKOMPLEXE VON WOLFRAM(IV)

Article abstract of DOI:10.1016/0022-328X(86)82078-2

The butadiyne complexes _x and _x are synthesized by the reaction of tungsten hexachloride with Me3SiC*CC*CSiMe3 and IC*CC*CI, respectively, in boiling CCl4.The complexes are associated by chloro bridges WCl2W.They react with pyridine or diethyl ether to form the adducts (X = SiMe3, I; Y = pyridine, diethyl ether).The thermally and mechanically very stable diiodobutadiyne complex reacts with (PPh3CH2I)Cl forming the chloro complex (PPhCH2I)2 which is very soluble in dichloromethane.This chloro complex reacts with silver chloride to form the dichlorobutadiyne complex (PPh3CH2I)2 which is also very stable.The results of IR and 13C NMR spectra correspond to the carbon-carbon triple bonds acting as four-electron donors, and the bonding to tungsten is best described as being of the metallacyclopropene type.