Alkylene oxide polymerization using a double metal cyanide catalyst complex and a magnesium, Group 3-Group 15 metal or lanthanide series metal compound

A method for producing a polyether monol or polyether polyol product, comprising

• (1) forming a catalyst mixture by combining (a) a double metal cyanide catalyst complex and (b) at least one aluminum compound not present during the preparation of the double metal cyanide catalyst complex, which aluminum compound is selected from the group consisting of trimethylaluminum, triethyl aluminum, tributyl aluminum, tribenzylaluminum, aluminum trimethoxide, aluminum triethoxide, aluminum triisopropoxide, aluminum tri-t-butoxide, aluminum tri-sec-butoxide, aluminum phenoxide, an aluminum phenoxide in which one or more of the phenoxide groups is ring-substituted with alkyl, CF3, cyano, COCH3, halogen, hydroxyl or alkoxyl, aluminum formate, aluminum acetate, aluminum propionate, aluminum 2-ethylhexanoate, aluminum benzoate, an aluminum benzoate in which one or more of the benzoate groups is ring-substituted with alkyl, CF3, cyano, COCH3, halogen, hydroxyl or alkoxyl, aluminum salicylate, aluminum 3,5-di-t-butyl salicylate;
• aluminum tris(dimethylamide), aluminum tris(diethylamide), aluminum tris(diphenylamide), aluminum tris(di(trimethylsilyl)amide), aluminum acetylacetonate;
• aluminum t-butylacetylacetonate;
• diethylaluminum ethoxide, dimethylaluminum ethoxide, diethylaluminum isopropoxide, dimethylaluminum isopropoxide, methyl aluminoxane, and tetraethyldialuminoxane,
• (2) combining the catalyst mixture with at least one alkylene oxide and then
• (3) polymerizing the alkylene oxide.