Catalyst for ring expansion metathesis polymerization of cyclic monomers
AssigneeUniversity of Florida Research Foundation, Inc.
InventorsAdam S. Veige, Stella Almeida Gonsales
Life of this patent
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Abstract
A tetraanionic OCO pincer ligand metal-oxo-alkylidene complex is prepared from a trianionic pincer ligand supported metal-alkylidyne. The metal can be tungsten or other group 5-7 transition metal. The tetraanionic pincer ligand metal-oxo-alkylidene complex, a trianionic OCO pincer ligand metal complex, or a trianionic ONO pincer ligand metal complex can be used to polymerize cycloalkenes. The poly(cycloalkene)s are predominantly cis-alkene macrocyclics.
Claims12
A tetraanionic pincer ligand metal-alkylidene complex of the structure:
- where:
- Z is independently O or S;
- R is, independently, H, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, or t-butyl;
- R′ is methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, C5-C22 alkyl, phenyl, naphthyl, or C13-C22 aryl;
- X is O, N, S, P, or Se;
- R″, independently, is methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, C5-C22 alkyl, phenyl, naphthyl, or C13-C22 aryl;
- or two R″ is a C4-C5 alkylene combined with a single X as a heterocycle;
- n is 2 or 3;
- and M is a group 6 transition metal.
A method of polymerizing a cyclic alkene, comprising
- providing a catalytic initiator selected from a tetraanionic OCO pincer ligand metal-alkylidene complex, a trianionic OCO pincer ligand metal complex, or a trianionic ONO pincer ligand metal complex;
- providing a plurality of cyclic alkene monomers;
- combining the catalytic initiator with the plurality of cyclic alkene monomers, and
- polymerizing the plurality of cyclic alkene monomers into a macrocyclic poly(alkene).
A stereoregular cyclic poly(cycloalkane) consisting of repeating units having greater than 95% syndiotactic content.
Dependencies are inferred from the claim text.