DOI: 10.21950/p3hods
title: Exploring Enantiopure Zinc-Scorpionates as Catalysts for the Preparation of Polylactides, Cyclic Carbonates, and Polycarbonates

description: This database includes all the catalytic data of complexes 7-9 in the ROP of rac-Lactide, Conversion of styrene oxide into styrene carbonate and synthesis of poly(cyclohexenecarbonate). The dataset also contains selected bond lengths [Å] and angles [°] for compound 6 and complex 9.
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Description of the project 
 New and simple ligand design strategies for the preparation of versatile metal-based catalysts capable of operating under greener and eco-friendly conditions in several industrially attractive processes are a priority demand for society development.
We present the first nucleophilic addition of an organolithium to ketenimines which incorporates a sterogenic centre in a N-donor atom to prepare new enantiopure NNN-donor scorpionates. We have also verified its potential utility as a valuable scaffold for chirality induction through the preparation of inexpensive, non-toxic and asymmetric zinc complexes. The pro-ligands and the corresponding zinc-based complexes have been characterized by X-Ray diffraction studies. DFT studies were carried out to rationalize the different complexation ability of these pro-ligands.
These complexes have proved to act as highly efficient catalysts for a variety of sustainable bioresourced processes industrially attractive, with wide substrate scope. Thus, complex 7 behaves as a highly efficient initiator for the well-behaved living ring-opening polymerization (ROP) of rac-lactide under very mild conditions. The PLA materials produced exhibited enhanced levels of isoselectivity, comparable to the highest value reported so far for zinc-based catalysts (Pi = 0.88).
In addition, the combination of 7 with onium halide salts functioned as a very active and selective catalyst for CO2 fixation into five‐membered cyclic carbonates through the cycloaddition of CO2 into epoxides under very mild and solvent-free conditions, reaching very good to excellent conversions (TOF = 227 h−1). Furthermore, these bicomponent system displays a broad substrate scope and functional group tolerance, including mono- and di-substituted epoxides, as well as the very challenging bio-renewable tri-substituted terpene-derived cis/trans-limonene oxide, whose reaction proceeds with high stereoselectivity. 
Finally, complex 7 also achieved high activity and selectivity as one-component initiator for the synthesis of poly(cyclohexene carbonate) via ring-opening copolymerization (ROCOP) of cyclohexene oxide and CO2 under very soft conditions, affording materials with narrow dispersity values.
description: Excel
description: Supplementary Information of the article which can be found with the article free of charge contains general experimental procedures, Intruments and measurements details, experimental synthesis of compounds and complexes including 1H and 13C{1H} NMR characterization, Details for crystallographic studies and structural refinement, Crystal data and structure refinement for 6c and 9, General procedures for catalytic studies, GPC traces corresponding to a poly(rac-lactide) sample, Selected area of MALDI-ToF mass spectrum of PLA synthesised by using 7, Deconvoluted 1H NMR spectra of the homodecoupled CH resonance of poly(rac-lactide) obtained by using 7, Tetrads area distribution and Pi value calculation, Experimental details for the synthesis of cyclic carbonates, 1H and 13C{1H} NMR of cyclic carbonates prepared, Experimental details for the synthesis of poly(cyclohexene carbonate), GPC traces of poly(cyclohexene carbonate)s produced by complex 7 at 50 °C and 20 bar CO2, 1H and 13C{1H} NMR of poly(cyclohexene carbonate) sample prepared using complex 7 at 50 °C and 20 bar CO2, MALDI-ToF mass spectrum of poly(cyclohexene carbonate) sample prepared using complex 7 at 50 °C and 20 bar CO2, Thermogravimetric analysis of a poly(cyclohexene carbonate) sample prepared using complex 7 at 50 °C and 20 bar CO2, Differential Scanning Calorimetry analysis of a poly(cyclohexene carbonate) sample prepared using complex 7 at 50 °C and 20 bar CO2, computational details, and input coordinates of optimized geometries.