These syntheses are repeated at stoichiometric ratios from 0.98:1.00 to 1.02:1.00
in 0.01 increments and at 5 ŽC temperature intervals to find the best conditions.
(Silanized glassware is necessary for the zirconium species because the zirconium
polymers condense with the hydroxyl groups on silica in DMSO and become firmly
attached to the glassware. Silanization is accomplished by coating the glassware
with a chloromethyl silane.) The best temperature for the polymerization reactions
with these metal ions appears to be somewhere between 55 and 70 ŽC and at exactly
1.00:1.00 stoichiometry.