Transition metal complexes supported on metal-organic frameworks for heterogeneous catalysts
A robust mesoporous metal-organic framework comprising a hafnium-based metal-organic framework and a single-site zirconium-benzyl species is provided. The hafnium, zirconium-benzyl metal-organic framework is useful as a catalyst for the polymerization of an alkene.
1. A compound comprising a reaction product of a hafnium-based metal-organic framework and a single-site zirconium-benzyl derivative.
2. The compound of claim 1 wherein the hafnium-based metal-organic framework has an organic portion comprising 1,3,6,8-tetrakis(p-benzoate)pyrene (TBAPy).
3. The compound of claim 2 wherein the single-site zirconium-benzyl derivative is tetrabenzylzirconium (ZrBn 4 ).
4. The compound of claim 3 wherein the hafnium-based metal-organic framework has a formula Hf 6 (OH) 16 (TBAPy) 2 .
5. The compound of claim 4 wherein the compound has on average 2.4 Zr per Hf 6 .
6. The compound of claim 4 wherein the compound has three Zr—O bonds and one Zr—Bn bonds.
7. The compound of claim 1 wherein the compound is crystalline.
8. A method of using a metal-organic framework for alkene polymerization, the method comprising:
providing a compound of claim 1 ;
contacting the compound with an alkene under at least one of a pressure and temperature sufficient to polymerize the alkene.
9. The method of claim 8 wherein the alkene is 1-hexene.
10. The method of claim 8 wherein the compound remains crystalline after the alkene is polymerized.
11. The method of claim 9 wherein the polymerized 1-hexene is stereoregular.
12. The method of claim 8 wherein the hafnium-based metal-organic framework has an organic portion comprising 1,3,6,8-tetrakis(p-benzoate)pyrene (TBAPy).
13. The method of claim 12 wherein the single-site zirconium-benzyl derivative is tetrabenzylzirconium (ZrBn 4 ).
14. The method of claim 13 wherein the hafnium-based metal-organic framework has a formula Hf 6 (OH) 16 (TBAPy) 2 .
15. The method of claim 14 wherein the compound has on average 2.4 Zr per Hf 6 .
16. The method of to claim 14 wherein the compound has three Zr—O bonds and one Zr—Bn bonds.
17. The method of claim 9 wherein the compound is crystalline.
18. The method of claim 17 wherein the compound remains crystalline after the alkene is polymerized.