Compositions and methods for olefin polymerization comprising metal organic frameworks

• US 10,442,875 B2
• Filed: 09/14/2016
• Issued: 10/15/2019
• Est. Priority Date: 09/14/2015
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Dinca, Mircea, Comito, Robert J.
• Primary Examiner(s): Lu, Caixia
• Application Number:
  US15/760,122
• Publication Number:
  US 20180251581A1
• Time in Patent Office: 1,126 Days
• CPC Class Codes: B01J 2231/10 Polymerisation reactions involving at least dual use catalysts, e.g. for both oligomerisation and polymerisation
• CPC Class Codes: B01J 23/06 of zinc, cadmium or mercury
• CPC Class Codes: B01J 23/24 Chromium, molybdenum or tungsten
• CPC Class Codes: B01J 2531/0216 Bi- or polynuclear complexes, i.e. comprising two or more metal coordination centres, without metal-metal bonds, e.g. Cp(Lx)Zr-imidazole-Zr(Lx)Cp
• CPC Class Codes: B01J 2531/26 Zinc
• CPC Class Codes: B01J 2531/46 Titanium
• CPC Class Codes: B01J 2531/62 Chromium
• CPC Class Codes: B01J 31/16 containing coordination complexes
• CPC Class Codes: B01J 31/1691 Coordination polymers, e.g. metal-organic frameworks [MOF] preparation of metal complexes containing carboxylic acid moieties C07C51/418; MOF's per se C07F
• CPC Class Codes: B01J 35/618 more than 1000 m2/g
• CPC Class Codes: C08F 10/02 Ethene
• CPC Class Codes: C08F 110/02 Ethene
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2410/03 Multinuclear procatalyst, i.e. containing two or more metals, being different or not
• CPC Class Codes: C08F 4/64 Titanium, zirconium, hafnium or compounds thereof
• CPC Class Codes: C08F 4/64003 the metallic compound containing a multidentate ligand, i.e. a ligand capable of donating two or more pairs of electrons to form a coordinate or ionic bond
• CPC Class Codes: C08F 4/64044 NN
• CPC Class Codes: C08F 4/642 Component covered by group C08F4/64 with an organo-aluminium compound C08F4/64003 - C08F4/64196 take precedence
• CPC Class Codes: C08F 4/69 Chromium, molybdenum, tungsten or compounds thereof
• CPC Class Codes: C08F 4/69008 the metallic compound containing a multidentate ligand, i.e. a ligand capable of donating two or more pairs of electrons to form a coordinate or ionic bond
• CPC Class Codes: C08F 4/69112 : NN

Abstract

Compositions and methods for selective olefin (e.g., ethylene) polymerization comprising metal organic frameworks (MOFs) are generally provided. In some embodiments, a MOF comprises a plurality of metal ions, each coordinated with at least one ligand comprising at least two unsaturated N-heterocyclic aromatic groups arranged about an organic core.

Claims

1. A method for forming a polyolefin from an olefin, the method comprising:

exposing the olefin to a metal organic framework (MOF) catalyst to produce the polyolefin,

wherein the MOF catalyst comprises a plurality of metal ions, each metal ion coordinated with at least one ligand, and

wherein the at least one ligand comprises at least two N-heterocyclic aromatic groups arranged about an organic core.

2. The method of claim 1, wherein the N-heterocyclic aromatic groups are selected from the group consisting of imidazolate, triazolate, and tetrazolate.

3. The method of claim 1, wherein the olefin is ethylene.

4. The method of claim 1, wherein the olefin comprises a combination of ethylene and propylene.

5. The method of claim 1, wherein the MOF comprises a first type of metal ion and a second type of metal ion.

6. The method of claim 5, wherein the first type of metal ion is selected from the group consisting of Sc³⁺, Ti³⁺, Ti⁴⁺, V²⁺,Cr²⁺, and Cr³⁺.

7. The method of claim 5 wherein the first type of metal ion is Cr²⁺ or Cr³⁺.

8. The method of claim 5 wherein the second type of metal ion is Zn⁺².

9. The method of claim 1, wherein the polyolefin is liner low-density polyethylene.

10. The method of claim 1, wherein each ligand comprises at least two N-heterocyclic aromatic groups arranged about an organic core, wherein the N-heterocyclic aromatic groups are selected from the group consisting of pyrazolate, pyridinate, imidazolate, triazolate, and tetrazolate.

11. The method of claim 1, wherein an additive is present during the exposing step.

12. The method of claim 11, wherein the additive is selected from the group consisting of an aluminoxane, methylaluminoxane, ethylaluminum dichloride, diethylaluminum chloride, triethylaluminum, an alkyl magnesium halide an alkyllithium, and trimethylaluminum.

13. The method of claim 11, wherein the additive is methylaluminoxane.

14. The method of claim 1, wherein the N-heterocyclic aromatic group is triazolate.

15. The method of claim 1, wherein the MOF comprises at least two ligands comprising triazolate.

16. The method of claim 1, wherein the exposing step is conducted in the presence of hydrogen.

21. The method of claim 1, wherein the MOF is as claimed in any one of claims 17-20.

17. A metal organic framework (MOF), comprising:

a plurality of metal ions, each coordinated with at least one ligand,

wherein the plurality of metal ions comprises at least two types of metal selected from the group consisting of Zn²⁺, Cr²⁺, and Cr³⁺, tetravalent metals, trivalent metals, and Zn⁺⁴, and

wherein the at least one ligand comprises the structure;

18. The MOF of claim 17, wherein each R¹ is hydrogen.

19. The MOF of claim 17, wherein the MOF is prepared via metal exchange of a substantially similar MOF comprising only Zn⁺².

20. The MOF of claim 17, wherein the plurality of metal ions comprises at least two types of metal selected from the group consisting of Zn²⁺, Cr²⁺, and Cr³.