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
Estimating the term…
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.
Claims10
A tetraanionic pincer ligand metal-oxo-alkylidene complex of the structure:
- where:
- Z is independently O or S;
- R comprises, independently, H, methyl, ethyl, n-propyl, propyl, n-butyl, i-butyl t-butyl, or larger alkyl;
- 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, phenyl, naphthyl, C13-C22 aryl, or two R″ is a C4-C6 alkylene combined with a single X as a heterocycle;
- n is 1 to 3;
- and M is a group 5-7 transition metal.
A method of polymerizing a cyclic alkene, comprising
- providing a catalytic initiator selected from a tetraanionic OCO pincer ligand metal-oxo-alkylidene complex, a trianionic OCO pincer ligand metal complex, or a trianionic ONO pincer ligand metal complex;
- providing a plurality of cyclic alkene monomers;
- and
- combining the catalytic initiator with the cyclic alkene monomers,
- polymerizing the plurality of cyclic alkene monomers into a macrocyclic poly(alkene).
A stereoregular cyclic polynorbornene, consisting of repeating units having greater than 95% cis content and greater than 95 syndiotactic content.
Dependencies are inferred from the claim text.