Polymerization of cyclic ethers using selected metal compound catalysts

A process for the polymerization of cyclic ethers, comprising, contacting at a temperature of about -80.degree. C. to about 90.degree. C. one or more tetrahydrofurans, oxepanes, 1,3-dioxolanes or 1,3,5-trioxanes with a compound of the formula MZ.sub.s .multidot.Q.sub.t, and an accelerator which is a compound of the formula ##STR4## wherein:

• R.sup.1 is hydrogen, hydrocarbyl or substituted hydrocarbyl in which a substituent does not react with the starting materials or products and does not interfere with the polymerization;
• R.sup.2 is hydrogen, hydrocarbyl or substituted hydrocarbyl in which a substituent does not react with the starting materials or products and does not interfere with the polymerization;
• each R.sup.3 is independently hydrocarbyl or substituted hydrocarbyl in which a substituent does not react with the starting materials or products and does not interfere with the polymerization;
• each X is independently chlorine, bromine or iodine;
• M is a metal selected from the group consisting of strontium, barium, scandium, yttrium, the rare earth metals, titanium, zirconium, hafnium, chromium, molybdenum, tantalum, rhenium, iron, cobalt, vanadium, niobium, tungsten, ruthenium, osmium, rhodium, iridium, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thulium, germanium, tin, mischmetall, lead, arsenic, antimony and bismuth;
• at least one of Z is an anion of the formula R.sup.5 SO.sub.3.sup.--, wherein R.sup.5 is perfluoroalkyl containing 1 to 12 carbon atoms or part of a fluorinated polymer wherein the carbon atoms alpha and beta to the sulfonate group are together bonded to at least four fluorine atoms, or tetraphenylborate, and the remainder of Z is oxo or one or more monovalent anions;
• s is 1 when M is silver;
• s is 2 when M is strontium, barium, copper, cobalt, rhodium, iridium, palladium, platinum, chromium, zinc, cadmium or mercury;
• s is 3 when M is scandium, yttrium, a rare earth metal, arsenic, antimony, bismuth, gold, iron, ruthenium, osmium, aluminum, gallium, mischmetall, indium or thulium;
• s is 4 when M is titanium, zirconium, hafnium, molybdenum, germanium, tin, or lead;
• s is 5 when M is rhenium, vanadium, niobium or tantalum;
• s is 6 when M is tungsten;
• Q is a neutral ligand;
• t is 0 or an integer of 1 to 6;
• and provided that each oxo group present as part of Z is considered to account for two of s.