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Project
Towards a Predictive Conceptual Model for Polymerization of Cyclic Esters Catalyzed by Group 14 Metal Complexes (FWOTM1003)
The search for sustainable alternatives for petroleum-based plastics
is one of the key challenges of the modern society. Such
biodegradable bioplastics are synthesized via controllable ringopening polymerization (ROP) of cyclic esters. ROP catalyst development has recently been dominated by cationic main group metal complexes. Surprisingly, tin based cationic complexes have
been overlooked so far, despite the fact that the industrial ROP is still catalyzed by a tin octanoate. The main research goal of this project is to build a conceptual predictive model for metal and ligand effects in ROP of selected cyclic esters catalyzed by cationic group 14 metal complexes. At first, a set of novel N,N-chelating ligands allowing for the formation of discrete cationic complexes of germanium and tin will be evaluated. The electronic and steric properties of the resulting complexes will be then assessed using a combination of conceptual DFT, energy decomposition analysis and topographic steric maps. Once a clear picture of the catalysts’ properties is obtained, detailed mechanistic studies coupled with the activation strain model and the
non-covalent interaction index will be used to reveal the ratedetermining transition states and intermediates. As such, the role of the ligand, metal and substrate in ROP will be fully rationalized with this novel conceptual framework, which will ultimately allow for the determination of a simple mathematical model for the future catalyst
design
is one of the key challenges of the modern society. Such
biodegradable bioplastics are synthesized via controllable ringopening polymerization (ROP) of cyclic esters. ROP catalyst development has recently been dominated by cationic main group metal complexes. Surprisingly, tin based cationic complexes have
been overlooked so far, despite the fact that the industrial ROP is still catalyzed by a tin octanoate. The main research goal of this project is to build a conceptual predictive model for metal and ligand effects in ROP of selected cyclic esters catalyzed by cationic group 14 metal complexes. At first, a set of novel N,N-chelating ligands allowing for the formation of discrete cationic complexes of germanium and tin will be evaluated. The electronic and steric properties of the resulting complexes will be then assessed using a combination of conceptual DFT, energy decomposition analysis and topographic steric maps. Once a clear picture of the catalysts’ properties is obtained, detailed mechanistic studies coupled with the activation strain model and the
non-covalent interaction index will be used to reveal the ratedetermining transition states and intermediates. As such, the role of the ligand, metal and substrate in ROP will be fully rationalized with this novel conceptual framework, which will ultimately allow for the determination of a simple mathematical model for the future catalyst
design
Date:1 Oct 2020 → 1 Jun 2023
Keywords:Density Functional Theory, Main Group Metal Catalysis, Ring-Opening Polymerization of Cyclic Esters
Disciplines:Coordination chemistry, Main group chemistry, Catalysis, Quantum chemistry, Theoretical and computational chemistry not elsewhere classified