Chromium Complexes Supported by Salen-Type Ligands for the Synthesis of Polyesters, Polycarbonates, and Their Copolymers through Chemoselective Catalysis
Abstract
:1. Introduction
2. Results and Discussion
2.1. Synthesis and Charactherization of Chromium Complexes
2.2. Copolymerizations of CO2 with Cyclohexene Oxide (CHO)
2.3. Copolymerization of Cyclohexene Oxide (CHO) and Limonene Oxide (LO) with Phthalic Anhydride (PA)
2.4. Terpolymerization of Cyclohexene Oxide (CHO) with Phthalic Anhydride (PA) and CO2
2.5. Chemical Depolymerization of PCHC
3. Materials and Methods
3.1. Reagents and Methods
3.2. Instruments
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
- Zhang, X.; Fevre, M.; Jones, G.O.; Waymouth, R.M. Catalysis as an Enabling Science for Sustainable Polymers. Chem. Rev. 2018, 118, 839–885. [Google Scholar] [CrossRef] [PubMed]
- Schneiderman, D.K.; Hillmyer, M.A. 50th Anniversary Perspective: There Is a Great Future in Sustainable Polymers. Macromolecules 2017, 50, 3733–3749. [Google Scholar] [CrossRef]
- Brannigan, R.P.; Dove, A.P. Synthesis, Properties and Biomedical Applications of Hydrolytically Degradable Materials Based on Aliphatic Polyesters and Polycarbonates. Biomater. Sci. 2017, 5, 9. [Google Scholar] [CrossRef] [PubMed]
- Paul, S.; Zhu, Y.; Romain, C.; Brooks, R.; Saini, P.K.; Williams, C.K. Ring-opening copolymerization (ROCOP): Synthesis and properties of polyesters and polycarbonates. Chem. Commun. 2015, 51, 6459–6479. [Google Scholar] [CrossRef] [PubMed]
- Longo, J.M.; Sanford, M.J.; Coates, G.W. Ring-Opening Copolymerization of Epoxides and Cyclic Anhydrides with Discrete Metal Complexes: Structure-Property Relationships. Chem. Rev. 2016, 116, 15167–15197. [Google Scholar] [CrossRef] [PubMed]
- Lidston, C.A.L.; Severson, S.M.; Abel, B.A.; Coates, G.W. Multifunctional Catalysts for Ring-Opening Copolymerizations. ACS Catal. 2022, 12, 11037–11070. [Google Scholar] [CrossRef]
- Kember, M.R.; Buchard, A.; Williams, C.K. Catalysts for CO2/epoxide copolymerization. Chem. Commun. 2011, 47, 141–163. [Google Scholar] [CrossRef]
- Klaus, S.; Lehenmeier, M.W.; Anderson, C.E.; Rieger, B. Recent advances in CO2/epoxide copolymerization—New strategies and cooperative mechanisms. Coord. Chem. Rev. 2011, 255, 1460–1479. [Google Scholar] [CrossRef]
- Trott, G.; Saini, P.K.; Williams, C.K. Catalysts for CO2/Epoxide Ring-Opening Copolymerization. Philos. Trans. R. Soc. A 2016, 374, 20150085. [Google Scholar] [CrossRef]
- Grignard, B.; Gennen, S.; Jérôme, C.; Kleij, A.W.; Detrembleur, C. Advances in the use of CO2 as a renewable feedstock for the synthesis of polymers. Chem. Soc. Rev. 2019, 48, 4466–4514. [Google Scholar] [CrossRef]
- Huang, J.; Worch, J.C.; Dove, A.P.; Coulembier, O. Update and Challenges in Carbon Dioxide-Based Polycarbonate Synthesis. ChemSusChem 2020, 13, 469–487. [Google Scholar] [CrossRef] [PubMed]
- D’Auria, I.; Santulli, F.; Ciccone, F.; Giannattasio, A.; Mazzeo, M.; Pappalardo, D. Synthesis of Semi-Aromatic Di-Block Polyesters by Terpolymerization of Macrolactones, Epoxides, and Anhydrides. ChemCatChem 2021, 13, 3303–3311. [Google Scholar] [CrossRef]
- Xia, X.; Suzuki, R.; Gao, T.; Isono, T.; Satoh, T. One-step synthesis of sequence-controlled multiblock polymers with up to 11 segments from monomer mixture. Nat. Commun. 2022, 13, 163. [Google Scholar] [CrossRef] [PubMed]
- Robert, C.; de Montigny, F.; Thomas, C.M. Tandem synthesis of alternating polyesters from renewable resources. Nat. Commun. 2011, 2, 586. [Google Scholar] [CrossRef] [PubMed]
- Romain, C.; Williams, C.K. Chemoselective Polymerization Control: From Mixed-Monomer Feedstock to Copolymers. Angew. Chem. Int. Ed. 2014, 53, 1607–1610. [Google Scholar] [CrossRef]
- Kernbichl, S.; Reiter, M.; Adams, F.; Vagin, S.; Rieger, B. CO2-Controlled One-Pot Synthesis of AB, ABA Block, and Statistical Terpolymers from β-Butyrolactone, Epoxides, and CO2. J. Am. Chem. Soc. 2017, 139, 6787–6790. [Google Scholar] [CrossRef] [PubMed]
- Thevenon, A.; Garden, J.A.; White, A.J.P.; Williams, C.K. Dinuclear Zinc Salen Catalysts for the Ring Opening Copolymerization of Epoxides and Carbon Dioxide or Anhydrides. Inorg. Chem. 2015, 54, 11906–11915. [Google Scholar] [CrossRef] [PubMed]
- Upitak, K.; Thomas, C.M. One-Pot Catalysis: A Privileged Approach for Sustainable Polymers? Acc. Chem. Res. 2022, 55, 2168–2179. [Google Scholar] [CrossRef]
- Stoesser, T.; Williams, C.K. Selective Polymerization Catalysis from Monomer Mixtures: Using a Commercial Cr-Salen Catalyst To Access ABA Block Polyesters. Angew. Chem. Int. Ed. 2018, 57, 6337–6341. [Google Scholar] [CrossRef] [PubMed]
- Diment, W.T.; Stößer, T.; Kerr, R.W.F.; Phanopoulos, A.; Durr, C.B.; Williams, C.K. Ortho-vanillin derived Al(iii) and Co(iii) catalyst systems for switchable catalysis using ε-decalactone, phthalic anhydride and cyclohexene oxide. Catal. Sci. Technol. 2021, 11, 1737–1745. [Google Scholar] [CrossRef]
- Isnard, F.; Carratu, M.; Lamberti, M.; Venditto, V.; Mazzeo, M. Copolymerization of cyclic esters, epoxides and anhydrides: Evidence of the dual role of the monomers in the reaction mixture. Catal. Sci. Technol. 2018, 8, 5034–5043. [Google Scholar] [CrossRef]
- Stoesser, T.; Mulryan, D.; Williams, C.K. Switch Catalysis To Deliver Multi-Block Polyesters from Mixtures of Propene Oxide, Lactide, and Phthalic Anhydride. Angew. Chem. Int. Ed. 2018, 57, 16893–16897. [Google Scholar] [CrossRef]
- Strianese, M.; Pappalardo, D.; Mazzeo, M.; Lamberti, M.; Pellecchia, C. Salen-type aluminum and zinc complexes as two-faced Janus compounds: Contribution to molecular sensing and polymerization catalysis. Dalton Trans. 2020, 49, 16533–16550. [Google Scholar] [CrossRef]
- Wang, Y.; Qin, Y.; Wang, X.; Wang, F. Trivalent Titanium Salen Complex: Thermally Robust and Highly Active Catalyst for Copolymerization of CO2 and Cyclohexene Oxide. ACS Catal. 2015, 5, 393–396. [Google Scholar] [CrossRef]
- Wang, W.-Z.; Zhang, K.-Y.; Jia, X.-G.; Wang, L.; Li, L.-L.; Fan, W.; Xia, L. A New Dinuclear Cobalt Complex for Copolymerization of CO2 and Propylene Oxide: High Activity and Selectivity. Molecules 2020, 25, 4095. [Google Scholar] [CrossRef] [PubMed]
- Qin, Z.; Thomas, C.M.; Lee, S.; Coates, G.W. Cobalt-Based Complexes for the Copolymerization of Propylene Oxide and CO2: Active and Selective Catalysts for Polycarbonate Synthesis. Angew. Chem. Int. Ed. 2003, 42, 5484–5487. [Google Scholar] [CrossRef] [PubMed]
- Darensbourg, D.J. Making plastics from carbon dioxide: Salen metal complexes as catalysts for the production of polycarbonates from epoxides and CO2. Chem. Rev. 2007, 107, 2388–2410. [Google Scholar] [CrossRef]
- Kamphuis, A.J.; Picchioni, F.; Pescarmona, P.P. CO2-fixation into cyclic and polymeric carbonates: Principles and applications. Green Chem. 2019, 21, 406–448. [Google Scholar] [CrossRef]
- Rao, D.Y.; Li, B.; Zhang, R.; Wang, H.; Lu, X.B. Binding of 4-(N,N-dimethylamino)pyridine to Salen- and Salan-Cr(III) cations: A mechanistic understanding on the difference in their catalytic activity for CO2/epoxide copolymerization. Inorg. Chem. 2009, 48, 2830–2836. [Google Scholar] [CrossRef]
- Nakano, K.; Nakamura, M.; Nozaki, K. Alternating Copolymerization of Cyclohexene Oxide with Carbon Dioxide Catalyzed by (salalen)CrCl Complexes. Macromolecules 2009, 42, 6972–6980. [Google Scholar] [CrossRef]
- Li, B.; Wu, G.-P.; Ren, W.-M.; Wang, Y.-M.; Rao, D.-Y.; Lu, X.-B. Asymmetric, regio- and stereo-selective alternating copolymerization of CO2 and propylene oxide catalyzed by chiral chromium salan complexes. J. Polym. Sci. Part A Polym. Chem. 2008, 46, 6102–6113. [Google Scholar] [CrossRef]
- Van Zee, N.J.; Coates, G.W. Alternating copolymerization of dihydrocoumarin and epoxides catalyzed by chromium salen complexes: A new route to functional polyesters. Chem. Commun. 2014, 50, 6322–6325. [Google Scholar] [CrossRef]
- Van Zee, N.J.; Coates, G.W. Alternating Copolymerization of Propylene Oxide with Biorenewable Terpene-Based Cyclic Anhydrides: A Sustainable Route to Aliphatic Polyesters with High Glass Transition Temperatures. Angew. Chem. Int. Ed. 2015, 54, 2665–2668. [Google Scholar] [CrossRef]
- Bester, K.; Bukowska, A.; Myśliwiec, B.; Hus, K.; Tomczyk, D.; Urbaniak, P.; Bukowski, W. Alternating ring-opening copolymerization of phthalic anhydride with epoxides catalysed by salophen chromium(iii) complexes. An effect of substituents in salophen ligands. Polym. Chem. 2018, 9, 2147–2156. [Google Scholar] [CrossRef]
- Wang, L.-Y.; Gu, G.-G.; Yue, T.-J.; Ren, W.-M.; Lu, X.-B. Semiaromatic Poly(thioester) from the Copolymerization of Phthalic Thioanhydride and Epoxide: Synthesis, Structure, and Properties. Macromolecules 2019, 52, 2439–2445. [Google Scholar] [CrossRef]
- Hosseini Nejad, E.; Paoniasari, A.; Koning, C.E.; Duchateau, R. Semi-aromatic polyesters by alternating ring-opening copolymerisation of styrene oxide and anhydrides. Polym. Chem. 2012, 3, 1308–1313. [Google Scholar] [CrossRef]
- Liu, Y.; Guo, J.-Z.; Lu, H.-W.; Wang, H.-B.; Lu, X.-B. Making Various Degradable Polymers from Epoxides Using a Versatile Dinuclear Chromium Catalyst. Macromolecules 2018, 51, 771–778. [Google Scholar] [CrossRef]
- He, G.-H.; Liu, Y.-L.; Liu, Y.; Lu, X.-B. Enantioselective Resolution Copolymerization of Racemic cis-Epoxides and Cyclic Anhydrides Mediated by Multichiral Bimetallic Chromium Complexes. Macromolecules 2022, 55, 3869–3876. [Google Scholar] [CrossRef]
- Hosseini Nejad, E.; van Melis, C.G.W.; Vermeer, T.J.; Koning, C.E.; Duchateau, R. Alternating Ring-Opening Polymerization of Cyclohexene Oxide and Anhydrides: Effect of Catalyst, Cocatalyst, and Anhydride Structure. Macromolecules 2012, 45, 1770–1776. [Google Scholar] [CrossRef]
- Liu, J.; Bao, Y.-Y.; Liu, Y.; Ren, W.-M.; Lu, X.-B. Binuclear chromium-salan complex catalyzed alternating copolymerization of epoxides and cyclic anhydrides. Polym. Chem. 2013, 4, 1439–1444. [Google Scholar] [CrossRef]
- Strianese, M.; D’Auria, G.J.; Lamberti, M.; Landi, A.; Peluso, A.; Varriale, A.; D’Auria, S.; Pellecchia, C. Salen, salan and salalen zinc(ii) complexes in the interaction with HS−: Time-resolved fluorescence applications. Dalton Trans. 2023, 52, 1357–1365. [Google Scholar] [CrossRef] [PubMed]
- Darensbourg, D.J.; Poland, R.R.; Escobedo, C. Kinetic Studies of the Alternating Copolymerization of Cyclic Acid Anhydrides and Epoxides, and the Terpolymerization of Cyclic Acid Anhydrides, Epoxides, and CO2 Catalyzed by (salen)CrIIICl. Macromolecules 2012, 45, 2242–2248. [Google Scholar] [CrossRef]
- Taherimehr, M.; Pescarmona, P.P. Green polycarbonates prepared by the copolymerization of CO2 with epoxides. J. Appl. Polym. Sci. 2014, 131, 41141. [Google Scholar] [CrossRef]
- Cozzolino, M.; Rosen, T.; Goldberg, I.; Mazzeo, M.; Lamberti, M. Selective Synthesis of Cyclic Carbonate by Salalen-Aluminum Complexes and Mechanistic Studies. ChemSusChem 2017, 10, 1217–1223. [Google Scholar] [CrossRef] [PubMed]
- Darensbourg, D.J.; Mackiewicz, R.M.; Rodgers, J.L.; Phelps, A.L. (Salen)CrIIIX Catalysts for the Copolymerization of Carbon Dioxide and Epoxides: Role of the Initiator and Cocatalyst. Inorg. Chem. 2004, 43, 1831–1833. [Google Scholar] [CrossRef]
- Darensbourg, D.J.; Mackiewicz, R.M.; Rodgers, J.L.; Fang, C.C.; Billodeaux, D.R.; Reibenspies, J.H. Cyclohexene oxide/CO2 copolymerization catalyzed by chromium(III) salen complexes and N-methylimidazole: Effects of varying salen ligand substituents and relative cocatalyst loading. Inorg. Chem. 2004, 43, 6024–6034. [Google Scholar] [CrossRef] [PubMed]
- Tache, A.; Litescu, S.-C.; Radu, G.-L. Spectroscopic studies on lipoprotein structure modification under oxidative stress. Spectroscopy 2011, 26, 414730. [Google Scholar] [CrossRef]
- Jutz, F.; Buchard, A.; Kember, M.R.; Fredriksen, S.B.; Williams, C.K. Mechanistic Investigation and Reaction Kinetics of the Low-Pressure Copolymerization of Cyclohexene Oxide and Carbon Dioxide Catalyzed by a Dizinc Complex. J. Am. Chem. Soc. 2011, 133, 17395–17405. [Google Scholar] [CrossRef]
- Darensbourg, D.J.; Mackiewicz, R.M.; Phelps, A.L.; Billodeaux, D.R. Copolymerization of CO2 and Epoxides Catalyzed by Metal Salen Complexes. Acc. Chem. Res. 2004, 37, 836–844. [Google Scholar] [CrossRef]
- Winkler, M.; Romain, C.; Meier, M.A.R.; Williams, C.K. Renewable polycarbonates and polyesters from 1,4-cyclohexadiene. Green Chem. 2015, 17, 300–306. [Google Scholar] [CrossRef]
- Giarola, S.; Romain, C.; Williams, C.K.; Hallett, J.P.; Shah, N. Techno-economic assessment of the production of phthalic anhydride from corn stover. Chem. Eng. Res. Des. 2016, 107, 181–194. [Google Scholar] [CrossRef]
- Ciriminna, R.; Lomeli-Rodriguez, M.; Demma Carà, P.; Lopez-Sanchez, J.A.; Pagliaro, M. Limonene: A versatile chemical of the bioeconomy. Chem. Commun. 2014, 50, 15288–15296. [Google Scholar] [CrossRef] [PubMed]
- D’Auria, I.; D’Aniello, S.; Viscusi, G.; Lamberti, E.; Gorrasi, G.; Mazzeo, M.; Pappalardo, D. One-Pot Terpolymerization of Macrolactones with Limonene Oxide and Phtalic Anhydride to Produce di-Block Semi-Aromatic Polyesters. Polymers 2022, 14, 4911. [Google Scholar] [CrossRef] [PubMed]
- Santulli, F.; D’Auria, I.; Boggioni, L.; Losio, S.; Proverbio, M.; Costabile, C.; Mazzeo, M. Bimetallic Aluminum Complexes Bearing Binaphthyl-Based Iminophenolate Ligands as Catalysts for the Synthesis of Polyesters. Organometallics 2020, 39, 1213–1220. [Google Scholar] [CrossRef]
- Isnard, F.; Santulli, F.; Cozzolino, M.; Lamberti, M.; Pellecchia, C.; Mazzeo, M. Tetracoordinate aluminum complexes bearing phenoxy-based ligands as catalysts for epoxide/anhydride copolymerization: Some mechanistic insights. Catal. Sci. Technol. 2019, 9, 3090–3098. [Google Scholar] [CrossRef]
- Nejad, E.H.; Paoniasari, A.; van Melis, C.G.W.; Koning, C.E.; Duchateau, R. Catalytic Ring-Opening Copolymerization of Limonene Oxide and Phthalic Anhydride: Toward Partially Renewable Polyesters. Macromolecules 2013, 46, 631–637. [Google Scholar] [CrossRef]
- Isnard, F.; Lamberti, M.; Pellecchia, C.; Mazzeo, M. Ring-Opening Copolymerization of Epoxides with Cyclic Anhydrides Promoted by Bimetallic and Monometallic Phenoxy-Imine Aluminum complexes. ChemCatChem 2017, 9, 2972–2979. [Google Scholar] [CrossRef]
- Aida, T.; Inoue, S. Metalloporphyrins as Initiators for Living and Immortal Polymerizations. Acc. Chem. Res. 1996, 29, 39–48. [Google Scholar] [CrossRef]
- Nomura, N.; Taira, A.; Nakase, A.; Tomioka, T.; Okada, M. Ring-opening polymerization of lactones by rare-earth metal triflates and by their reusable system in ionic liquids. Tetrahedron 2007, 63, 8478–8484. [Google Scholar] [CrossRef]
- Li, X.-L.; Ma, K.; Xu, F.; Xu, T.-Q. Advances in the Synthesis of Chemically Recyclable Polymers. Chem.–Asian J. 2023, 18, e202201167. [Google Scholar] [CrossRef]
- Liu, Y.; Lu, X.-B. Emerging Trends in Closed-Loop Recycling Polymers: Monomer Design and Catalytic Bulk Depolymerization. Chem.-Eur. J. 2023, e202203635. [Google Scholar] [CrossRef] [PubMed]
- Singer, F.N.; Deacy, A.C.; McGuire, T.M.; Williams, C.K.; Buchard, A. Chemical Recycling of Poly(Cyclohexene Carbonate) Using a Di-MgII Catalyst. Angew. Chem. Int. Ed. 2022, 61, e202201785. [Google Scholar] [CrossRef] [PubMed]
- McGuire, T.M.; Deacy, A.C.; Buchard, A.; Williams, C.K. Solid-State Chemical Recycling of Polycarbonates to Epoxides and Carbon Dioxide Using a Heterodinuclear Mg(II)Co(II) Catalyst. J. Am. Chem. Soc. 2022, 144, 18444–18449. [Google Scholar] [CrossRef] [PubMed]
- Yu, Y.; Gao, B.; Liu, Y.; Lu, X.-B. Efficient and Selective Chemical Recycling of CO2-Based Alicyclic Polycarbonates via Catalytic Pyrolysis. Angew. Chem. Int. Ed. 2022, 61, e202204492. [Google Scholar] [CrossRef] [PubMed]
- Ali, A.; Muhammad, N.; Hussain, S.; Jamil, M.I.; Uddin, A.; Aziz, T.; Tufail, M.K.; Guo, Y.; Wei, T.; Rasool, G.; et al. Kinetic and Thermal Study of Ethylene and Propylene Homo Polymerization Catalyzed by ansa-Zirconocene Activated with Alkylaluminum/Borate: Effects of Alkylaluminum on Polymerization Kinetics and Polymer Structure. Polymers 2021, 13, 268. [Google Scholar] [CrossRef] [PubMed]
Entry [a] | Cat | Conv. [b] (%) | Mn [c] (Kg/mol) | Đ [c] | Tg (°C) | Td (°C) |
---|---|---|---|---|---|---|
1 | 1 | 14 | - | - | - | - |
2 | 2 | 36 | 7.44 | 1.22 | 120.92 | 248 |
3 | 3 | 27 | 6.30 | 1.25 | 111.11 | 219 |
4 | 4 | 47 | 9.61 | 1.17 | 121.83 | 235 |
Entry | Cat | Epoxide | T (°C) | Time (min) | Conv. [c] (%) | Mn [d] (kg/mol) | Đ [d] |
---|---|---|---|---|---|---|---|
1 [a] | 1 | CHO | 70 | 30 | 93 | 2.84 | 1.34 |
2 [a] | 2 | CHO | 70 | 60 | 100 | 4.84 | 1.30 |
3 [a] | 3 | CHO | 70 | 60 | 87 | 3.22 | 1.50 |
4 [a] | 4 | CHO | 70 | 30 | 100 | 3.70 | 1.19 |
5 [b] | 1 | LO | 110 | 15 | 63 | 3.75 | 1.24 |
6 [b] | 2 | LO | 110 | 15 | 49 | 4.37 | 1.24 |
7 [b] | 3 | LO | 110 | 15 | 43 | 1.03 | 1.47 |
8 [b] | 4 | LO | 110 | 15 | 100 | 3.51 | 1.26 |
Entry [a] | Cat | Co-Cat | PE:PCHC [b] | Mn [c] (Kg/mol) | Đ [c] |
---|---|---|---|---|---|
1 | 1 | PPNCl | 47:53 | 6.26 | 1.23 |
2 | 2 | PPNCl | 37:63 | 8.40 | 1.23 |
3 | 3 | PPNCl | 48:52 | 7.21 | 1.25 |
4 | 4 | PPNCl | 28:72 | 8.31 | 1.16 |
Entry [a] | Cat | Time (min) | Conv [b] (%) | CHO [b] (%) | cis-CHC [b] (%) | trans-CHC [b] (%) |
---|---|---|---|---|---|---|
1 | 1 | 10 | 94 | 97 | 2 | 1 |
2 | 1 | 5 | 75 | 96 | 2 | 2 |
3 | 2 | 5 | 56 | 95 | 2 | 3 |
4 | 3 | 5 | 12 | 95 | 3 | 2 |
5 [c] | 1 | 5 | 23 | 19 | 2 | 2 |
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
Grimaldi, I.; Santulli, F.; Lamberti, M.; Mazzeo, M. Chromium Complexes Supported by Salen-Type Ligands for the Synthesis of Polyesters, Polycarbonates, and Their Copolymers through Chemoselective Catalysis. Int. J. Mol. Sci. 2023, 24, 7642. https://doi.org/10.3390/ijms24087642
Grimaldi I, Santulli F, Lamberti M, Mazzeo M. Chromium Complexes Supported by Salen-Type Ligands for the Synthesis of Polyesters, Polycarbonates, and Their Copolymers through Chemoselective Catalysis. International Journal of Molecular Sciences. 2023; 24(8):7642. https://doi.org/10.3390/ijms24087642
Chicago/Turabian StyleGrimaldi, Ilaria, Federica Santulli, Marina Lamberti, and Mina Mazzeo. 2023. "Chromium Complexes Supported by Salen-Type Ligands for the Synthesis of Polyesters, Polycarbonates, and Their Copolymers through Chemoselective Catalysis" International Journal of Molecular Sciences 24, no. 8: 7642. https://doi.org/10.3390/ijms24087642