Stereoselectivity Control Interplay in Racemic Lactide Polymerization by Achiral Al‐Salen Complexes DOI Creative Commons
Serena Moccia,

Massimo Christian D’ Alterio,

Eugenio Romano

et al.

Macromolecular Rapid Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 22, 2024

Abstract The origin of stereocontrol in ring opening polymerization (ROP) racemic lactide ( rac ‐LA) promoted by achiral aluminium‐based catalysts has been explained through DFT calculations combined with a molecular descriptor (% V Bur ) and the activation strain model (ASM‐NEDA) analysis. proposed chain end control (CEC) suggests that ligand framework adopts chiral configuration mimicking enantiomorphic site (ESC) while also incorporating last inserted monomer unit. It is found wrapping mode around aluminium centre dictated R , ‐LA S ‐LA). A good correlation experimental data achieved only when accounting for dynamic features its steric influences, as highlighted % maps ASM‐NEDA Understanding ESC CEC interplay an important target obtaining stereoselective ROP synthesis biodegradable materials tailored properties.

Language: Английский

Optimization of Starting Material Composition in the Synthesis of Highly Active Magnesium Ethoxide‐Supported Ziegler–Natta Catalysts for Propylene Polymerization DOI Open Access
Nona Ghasemi Hamedani, Mina Behrouzi‐Fardmoghadam, Hossein Abedini

et al.

Journal of Polymer Science, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 6, 2025

ABSTRACT We aim to deepen our understanding of the structure‐performance relationship in Ziegler–Natta catalysts (ZNCs) for propylene polymerization. To this end, three different Mg(OEt)₂ supports were synthesized by reacting magnesium powder with varying amounts MnCl₂ during magnesium‐ethanol reaction stage. Despite similar XRD patterns among all obtained Mg(OEt) 2 samples, at an optimal MnCl /Mg ratio g/g, well‐spherically shaped particles plate‐like building units formed. The prepared support precursors then used ZNC synthesis TiCl₄/Mg(OEt)₂ ratios and internal donor types, their behavior polymerization was thoroughly explored. overall results indicated that Ti/Mg is 8 mol/mol. Additionally, phthalate as demonstrated higher activity compared diethyl ether or succinate‐based donors. kinetic curve uptake versus time experiments external content mathematically modeled evaluate changes rate constants. calculated constants showed increases, k trH , d iED tED enhance, while p decreases significantly due poisoning active sites donor. These findings highlight critical role type amount catalyst components achieving performance.

Language: Английский

Citations

0
Looking into the Quest for Stereoselective Ring-Opening Polymerization of Racemic Lactide with Chiral Organocatalysts DOI
Rachele Zunino, Laura Falivene, Giovanni Talarico

et al.

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 4141 - 4146

Published: Feb. 22, 2025

Language: Английский

Citations

0
Organocatalyzed Ring-Opening Polymerization of Meso-Lactide Reveals Competing Mechanisms of Stereocontrol DOI
Rachele Zunino, Laura Falivene, Giovanni Talarico

et al.

Published: Jan. 1, 2025

Language: Английский

Citations

0
Synthesis of Aluminum Complexes Based on 2,6‐Bis(2‐hydroxyphenyl)Pyridines: Efficient Initiators for Ring‐Opening Polymerization of Cyclic Esters DOI
Valeriia A. Serova,

А. А. Лыков,

Badma N. Mankaev

et al.

ChemistrySelect, Journal Year: 2024, Volume and Issue: 9(45)

Published: Dec. 1, 2024

Abstract The search for new initiators based on nontoxic metal complexes, allowing the controlled production of polycaprolactone (PCL) and polylactide (PLA) is an actual task. In present work, we report synthesis aluminum complexes 6a 6b substituted 2,6‐bis(2‐hydroxyphenyl)pyridine pro‐ligands. compositions structures novel compounds were established by elemental analysis 1 H, 13 C, NMR spectroscopy in solid state X‐ray diffraction ( ). All synthesized are monomeric. Complexes (in presence benzyl alcohol (BnOH)) turned out to be active ring opening polymerization (ROP) ε ‐caprolactone ‐CL), L‐, rac‐ lactide (L‐, rac ‐LA) gave PCL PLA with high molecular weights. mechanism reaction С , 6a, was also investigated using density functional theory (DFT) method. substituent effect analyzed terms percent buried volume non‐covalent interactions. values calculated Gibbs free activation energies correspond trend found experimentally.

Language: Английский

Citations

2
Stereoselectivity Control Interplay in Racemic Lactide Polymerization by Achiral Al‐Salen Complexes DOI Creative Commons
Serena Moccia,

Massimo Christian D’ Alterio,

Eugenio Romano

et al.

Macromolecular Rapid Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 22, 2024

Abstract The origin of stereocontrol in ring opening polymerization (ROP) racemic lactide ( rac ‐LA) promoted by achiral aluminium‐based catalysts has been explained through DFT calculations combined with a molecular descriptor (% V Bur ) and the activation strain model (ASM‐NEDA) analysis. proposed chain end control (CEC) suggests that ligand framework adopts chiral configuration mimicking enantiomorphic site (ESC) while also incorporating last inserted monomer unit. It is found wrapping mode around aluminium centre dictated R , ‐LA S ‐LA). A good correlation experimental data achieved only when accounting for dynamic features its steric influences, as highlighted % maps ASM‐NEDA Understanding ESC CEC interplay an important target obtaining stereoselective ROP synthesis biodegradable materials tailored properties.

Language: Английский

Citations

1