Ring-opening metathesis polymerisation

For other uses of "ROMP", see Romp (disambiguation).

In polymer chemistry, ring-opening metathesis polymerization (ROMP) is a type of chain-growth polymerization involving olefin metathesis.^[1] The reaction is driven by relieving ring strain in cyclic olefins.^[2] A variety of heterogeneous and homogeneous catalysts have been developed for different polymers and mechanisms.^[3] Heterogeneous catalysts are typical in large-scale commercial processes, while homogeneous catalysts are used in finer laboratory chemical syntheses.^[4] Organometallic catalysts used in ROMP usually have transition metal centres, such as tungsten, rubidium, titanium, etc., with organic ligands.^[5]

Heterogeneous catalysis

ROMP reaction giving polynorbornene. Like most commercial alkene metathesis processes, this reaction does not employ a well-defined molecular catalyst.

Heterogeneous catalysis consists of catalysts and substrates in different physical states. The catalyst is typically in solid phase.^[6] The mechanism of heterogeneous ring-opening metathesis polymerization is still under investigation.^[7]

Ring-opening metathesis polymerization of cyclic olefins has been commercialized since the 1970s.^[4] Examples of polymers produced on an industrial level through ROMP catalysis are Vestenamer, Norsorex and ZEONEX, among others.^[8]

Mechanism

The mechanism of homogeneous ring-opening metathesis polymerization is well-studied. It is similar to any olefin metathesis reaction. Initiation occurs by forming an open coordination site on the catalyst. Propagation happens via a metallacycle intermediate formed after a 2+2 cycloaddition. When using a G3 catalyst, 2+2 cycloaddition is the rate determining step.^[9]

Frontal ring-opening metathesis polymerization

Frontal ring-opening metathesis polymerization (FROMP) is a variation of ROMP. It is a polymerization system that only reacts on a localized zone.^[10] One example of this system is the FROMP of dicyclopentadiene with a Grubbs' catalyst initiated by heat.^[11]

See also

• Acyclic diene metathesis
• Ring-opening polymerization

Further reading

• Bano, Tahira; Zahoor, Ameer Fawad; Rasool, Nasir; Irfan, Muhammad; Mansha, Asim (June 2022). "Recent trends in Grubbs catalysis toward the synthesis of natural products: a review". Journal of the Iranian Chemical Society. 19 (6): 2131–2170. doi:10.1007/s13738-021-02463-x. ISSN 1735-207X.
• Sveinbjörnsson, Benjamin R.; Weitekamp, Raymond A.; Miyake, Garret M.; Xia, Yan; Atwater, Harry A.; Grubbs, Robert H. (2012-09-04). "Rapid self-assembly of brush block copolymers to photonic crystals". Proceedings of the National Academy of Sciences. 109 (36): 14332–14336. Bibcode:2012PNAS..10914332S. doi:10.1073/pnas.1213055109. PMC 3437898. PMID 22912408.

References

1. Buchmeiser, Michael R. (2009-01-28), Dubois, Philippe; Coulembier, Olivier; Raquez, Jean-Marie (eds.), "Ring-Opening Metathesis Polymerization", Handbook of Ring-Opening Polymerization (1 ed.), Wiley, pp. 197–225, doi:10.1002/9783527628407.ch8, ISBN 978-3-527-31953-4, retrieved 2024-12-02
2. Duda, Andrzej; Kowalski, Adam (2009-01-28), Dubois, Philippe; Coulembier, Olivier; Raquez, Jean-Marie (eds.), "Thermodynamics and Kinetics of Ring-Opening Polymerization", Handbook of Ring-Opening Polymerization (1 ed.), Wiley, pp. 1–51, doi:10.1002/9783527628407.ch1, ISBN 978-3-527-31953-4, retrieved 2024-12-02
3. Hilf, Stefan; Kilbinger, Andreas F. M. (2009-09-23). "Functional end groups for polymers prepared using ring-opening metathesis polymerization". Nature Chemistry. 1 (7): 537–546. Bibcode:2009NatCh...1..537H. doi:10.1038/nchem.347. ISSN 1755-4330. PMID 21378934.
4. Kirk-Othmer, ed. (2001-01-26). Kirk-Othmer Encyclopedia of Chemical Technology (1 ed.). Wiley. doi:10.1002/0471238961.metanoel.a01. ISBN 978-0-471-48494-3.
5. Cowie, J. M. G.; Arrighi, V. (2008). Polymers: chemistry and physics of modern materials (3rd ed.). Boca Raton: CRC Press. ISBN 978-0-8493-9813-1. OCLC 82473191.
6. Ehrhorn, Henrike; Tamm, Matthias (March 2019). "Well-Defined Alkyne Metathesis Catalysts: Developments and Recent Applications". Chemistry – A European Journal. 25 (13): 3190–3208. doi:10.1002/chem.201804511. ISSN 0947-6539. PMID 30346054.
7. Greenlee, Andrew J.; Weitekamp, Raymond A.; Foster, Jeffrey C.; Leguizamon, Samuel C. (2024-04-19). "PhotoROMP: The Future Is Bright". ACS Catalysis. 14 (8): 6217–6227. doi:10.1021/acscatal.4c00972. ISSN 2155-5435. PMC 11036397. PMID 38660608.
8. Mol, J. C. (2004-04-13). "Industrial applications of olefin metathesis". Journal of Molecular Catalysis A: Chemical. The 15th. International Symposium on Olefin Metathesis and Related Chemistry. 213 (1): 39–45. doi:10.1016/j.molcata.2003.10.049. ISSN 1381-1169.
9. Hyatt, Michael G.; Walsh, Dylan J.; Lord, Richard L.; Andino Martinez, José G.; Guironnet, Damien (2019-11-06). "Mechanistic and Kinetic Studies of the Ring Opening Metathesis Polymerization of Norbornenyl Monomers by a Grubbs Third Generation Catalyst". Journal of the American Chemical Society. 141 (44): 17918–17925. doi:10.1021/jacs.9b09752. ISSN 0002-7863.
10. Pojman, J.A. (2012), "Frontal Polymerization", Polymer Science: A Comprehensive Reference, Elsevier, pp. 957–980, doi:10.1016/b978-0-444-53349-4.00124-2, ISBN 978-0-08-087862-1, retrieved 2024-12-02
11. Moneypenny, Timothy P.; Liu, Huiying; Yang, Anna; Robertson, Ian D.; Moore, Jeffrey S. (2017-04-13). "Grubbs-inspired metathesis in the Moore group". Journal of Polymer Science Part A: Polymer Chemistry. 55 (18): 2935–2948. Bibcode:2017JPoSA..55.2935M. doi:10.1002/pola.28592. ISSN 0887-624X.