Structural diversity of polynuclear Mg x O y cores in magnesium phenoxide complexes

2017 ◽  
Vol 73 (11) ◽  
pp. 854-861 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Andrei V. Churakov ◽  
Ilya E. Nifant'ev
Keyword(s):  
Ring Opening ◽  
Binuclear Complex ◽  
Coordination Mode ◽  
Structural Diversity ◽  
Ring Opening Polymerization ◽  
Trinuclear Complex ◽  
Tetranuclear Complex ◽  
Mg Complexes

The binuclear complex bis(2,6-di-tert-butyl-4-methylphenolato)-1κO,2κO-(1,2-dimethoxyethane-1κ2 O,O′)bis(μ-phenylmethanolato-1:2κ2 O:O)(tetrahydrofuran-2κO)dimagnesium(II), [Mg2(C7H7O)2(C15H23O)2(C4H8O)(C4H10O2)] or [(BHT)(DME)Mg(μ-OBn)2Mg(THF)(BHT)], (I), was obtained from the complex [(BHT)Mg(μ-OBn)(THF)]2 by substitution of one tetrahydrofuran (THF) molecule with 1,2-dimethoxyethane (DME) in toluene (BHT is O-2,6- t Bu2-4-MeC6H4 and Bn is benzyl). The trinuclear complex bis(2,6-di-tert-butyl-4-methylphenolato)-1κO,3κO-tetrakis(μ-2-methylphenolato)-1:2κ4 O:O;2:3κ4 O:O-bis(tetrahydrofuran)-1κO,3κO-trimagnesium(II), [Mg3(C7H7O)4(C15H23O)2(C4H8O)2] or [(BHT)2(μ-O-2-MeC6H4)4(THF)2Mg3], (II), was formed from a mixture of Bu2Mg, [(BHT)Mg( n Bu)(THF)2] and 2-methylphenol. An unusual tetranuclear complex, bis(μ3-2-aminoethanolato-κ4 O:O:O,N)tetrakis(μ2-2-aminoethanolato-κ3 O:O,N)bis(2,6-di-tert-butyl-4-methylphenolato-κO)tetramagnesium(II), [Mg4(C2H6NO)6(C15H23O)2] or Mg4(BHT)2(OCH2CH2NH2)6, (III), resulted from the reaction between (BHT)2Mg(THF)2 and 2-aminoethanol. A polymerization test demonstrated the ability of (III) to catalyse the ring-opening polymerization of ∊-caprolactone without activation by alcohol. In all three complexes (I)–(III), the BHT ligand demonstrates the terminal κO-coordination mode. Complexes (I), (II) and (III) have binuclear rhomboid Mg2O2, trinuclear chain-like Mg3O4 and bicubic Mg4O6 cores, respectively. A survey of the literature on known polynuclear Mg x O y core types for ArO–Mg complexes is also presented.

scholarly journals Bis[μ-bis(2,6-diisopropylphenyl) phosphato-κ2 O:O′]bis[(2,2′-bipyridine-κ2 N,N′)lithium] toluene disolvate and its catalytic activity in ring-opening polymerization of ∊-caprolactone and L-dilactide

2019 ◽  
Vol 75 (6) ◽  
pp. 848-853
Author(s):  
Alexey E. Kalugin ◽  
Pavel D. Komarov ◽  
Mikhail E. Minyaev ◽  
Konstantin A. Lyssenko ◽  
Dmitrii M. Roitershtein ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ring Opening ◽  
Coordination Mode ◽  
Complex Molecule ◽  
Ring Opening Polymerization ◽  
Title Complex ◽  
Asymmetric Unit ◽  
Isopropyl Group ◽  
Catalytic Systems ◽  
Phosphate Ligand

The solvated centrosymmmtric title compound, [Li2(C24H34O4P)2(C10H8N2)2]·2C7H8, was formed in the reaction between {Li[(2,6-iPr2C6H3-O)2POO](MeOH)3}(MeOH) and 2,2′-bipyridine (bipy) in toluene. The structure has monoclinic (P21/n) symmetry at 120 K and the asymmetric unit consists of half a complex molecule and one molecule of toluene solvent. The diaryl phosphate ligand demonstrates a μ-κO:κO′-bridging coordination mode and the 2,2′-bipyridine ligand is chelating to the Li+ cation, generating a distorted tetrahedral LiN2O2 coordination polyhedron. The complex exhibits a unique dimeric Li2O4P2 core. One isopropyl group is disordered over two orientations in a 0.621 (4):0.379 (4) ratio. In the crystal, weak C—H...O and C—H...π interactions help to consolidate the packing. Catalytic systems based on the title complex and on the closely related complex {Li[(2,6-iPr2C6H3-O)2POO](MeOH)3}(MeOH) display activity in the ring-opening polymerization of ∊-caprolactone and L-dilactide.

Phenoxide and alkoxide complexes of Mg, Al and Zn, and their use for the ring-opening polymerization of ∊-caprolactone with initiators of different natures

2018 ◽  
Vol 74 (5) ◽  
pp. 548-557 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Ilya E. Nifant'ev ◽  
Andrey V. Shlyakhtin ◽  
Pavel V. Ivchenko ◽  
Konstantin A. Lyssenko
Keyword(s):  
Ring Opening ◽  
Coordination Mode ◽  
Phenyl Group ◽  
Ring Opening Polymerization ◽  
Dalton Trans ◽  
Methyl Group ◽  
Positional Disorder ◽  
Structural Database ◽  
Independent Molecules ◽  
Derivatives Of

A new packing polymorph of bis(2,6-di-tert-butyl-4-methylphenolato-κO)bis(tetrahydrofuran-κO)magnesium, [Mg(C15H23O)2(C4H8O)2] or Mg(BHT)2(THF)2, (BHT is the 2,6-di-tert-butyl-4-methylphenoxide anion and THF is tetrahydrofuran), (1), has the same space group (P21) as the previously reported modification [Nifant'ev et al. (2017d). Dalton Trans. 46, 12132–12146], but contains three crystallographically independent molecules instead of one. The structure of (1) exhibits rotational disorder of the tert-butyl groups and positional disorder of a THF ligand. The complex of bis(2,6-di-tert-butyl-4-methylphenolato-κO)bis(μ2-ethyl glycolato-κ2 O,O′:κO)dimethyldialuminium, [Al2(CH3)2(C4H7O3)2(C15H23O)2] or [(BHT)AlMe(OCH2COOEt)]2, (2), is a dimer located on an inversion centre and has an Al2O2 rhomboid core. The 2-ethoxy-2-oxoethanolate ligand (OCH2COOEt) displays a μ2-κ2 O,O′:κO semi-bridging coordination mode, forming a five-membered heteronuclear Al–O–C–C–O ring. The same ligand exhibits positional disorder of the terminal methyl group. The redetermined structure of the heptanuclear complex octakis(μ3-benzyloxo-κO:κO:κO)hexaethylheptazinc, [Zn7(C2H5)6(C7H7O)8] or [Zn7(OCH2Ph)8Et6], (3), possesses a bicubic Zn7O8 core located at an inversion centre and demonstrates positional disorder of one crystallographically independent phenyl group. Cambridge Structural Database surveys are given for complexes structurally analogous to (2) and (3). Complexes (2) and (3), as well as derivatives of (1), are of interest as catalysts for the ring-opening polymerization of ∊-caprolactone, and polymerization results are reported.

A Recommender System for Inverse Design of Polycarbonates and Polyesters

2020 ◽  
Author(s):  
Nathaniel Park ◽  
Dmitry Yu. Zubarev ◽  
James L. Hedrick ◽  
Vivien Kiyek ◽  
Christiaan Corbet ◽  
...  
Keyword(s):  
Ring Opening ◽  
High Performance ◽  
Recommendation System ◽  
Polymeric Materials ◽  
Monomer Conversion ◽  
Design Strategy ◽  
Ring Opening Polymerization ◽  
Inverse Design ◽  
False Negatives ◽  
Accelerate Development

The convergence of artificial intelligence and machine learning with material science holds significant promise to rapidly accelerate development timelines of new high-performance polymeric materials. Within this context, we report an inverse design strategy for polycarbonate and polyester discovery based on a recommendation system that proposes polymerization experiments that are likely to produce materials with targeted properties. Following recommendations of the system driven by the historical ring-opening polymerization results, we carried out experiments targeting specific ranges of monomer conversion and dispersity of the polymers obtained from cyclic lactones and carbonates. The results of the experiments were in close agreement with the recommendation targets with few false negatives or positives obtained for each class.<br>

Bisurea and Bisthiourea H-Bonding Organocatalysts for Ring-Opening Polymerization: Cues for the Catalyst Design

2019 ◽  
Vol 52 (23) ◽  
pp. 9232-9237 ◽  
Author(s):  
Rukshika S. Hewawasam ◽  
U. L. D. Inush Kalana ◽  
Nayanthara U. Dharmaratne ◽  
Thomas J. Wright ◽  
Timothy J. Bannin ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Catalyst Design
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