Ruthenium complex polymers experimental

These ruthenium complexes react rapidly and quantitatively with ethyl vinyl ether to form a Fischer carbene that is only weakly metathesis active at elevated temperatures [86, 87]. This property can be employed to end-cap ROMP and ADMET polymers and to ensure that there are no polymeric ruthenium alkyhdenes present. Since ruthenium alkylidenes are relatively robust complexes they could survive workup procedures, although experimental evidence has yet to confirm this notion. Treatment of an ADMET polymer with ethyl vinyl ether gives the polymer well-defined terminal olefinic endgroups and should prevent backbiting metathesis upon dilution of the polymer (Scheme 6.22). 

The synthesis of DCH-Ru polymers 5-8 was performed in the same manner as that of the comparable dinuclear ruthenium complexes previously reported, since early experimentation revealed that the poljdiydrazines were freely soluble in weak aqueous base solutions. The ruthenium-containing polymers were isolated by precipitation, but unfortunately could not be further purified by filtering through a neutral alumina-packed column as was used for purificaticm of DCH-Ru complexes. The DCH-Ru polymers were absorbed strongly on the alumina gels and therefore were used as synthesized for all physical characterization reported herein. 

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