Redox-switchable ring-opening polymerization by tridentate ONN-type titanium and zirconium catalysts

2020 ◽  
Vol 10 (19) ◽  
pp. 6501-6510 ◽  
Author(s):  
Alicia M. Doerr ◽  
Justin M. Burroughs ◽  
Nicholas M. Legaux ◽  
Brian K. Long
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Metal Center ◽  
Redox Active ◽  
Active Metal ◽  
Zirconium Catalysts ◽  
Symmetry Number ◽  
The Impact

A study designed to ascertain the impact that ligand symmetry, number of redox-active moieties, and identity of the active metal center have on the catalytic ring-opening polymerization performance of redox-switchable catalysts.

scholarly journals Spectroscopic and theoretical investigation of the [Fe2(bdt)(CO)6] hydrogenase mimic and some catalyst intermediates

2019 ◽  
Vol 21 (27) ◽  
pp. 14638-14645 ◽  
Author(s):  
J. P. H. Oudsen ◽  
B. Venderbosch ◽  
D. J. Martin ◽  
T. J. Korstanje ◽  
J. N. H. Reek ◽  
...  
Keyword(s):  
Theoretical Investigation ◽  
Metal Center ◽  
Redox Active ◽  
Active Metal ◽  
Redox Active Metal

In [Fe–Fe] hydrogenase mimic systems the ene-1,2-dithiolene ligands play an important role in the stabilisation of the redox-active metal center.

scholarly journals Chemical bonding of polycaprolactone on the surface of hydroxyapatite via silanization and ring opening polymerization

2020 ◽  
Vol 19 (2) ◽  
pp. 154-164
Author(s):  
Nadir Slimani ◽  
Giovanni Dal Poggetto ◽  
Paola Laurienzo ◽  
Dalila Ksouri ◽  
Hafit Khireddine
Keyword(s):  
Surface Modification ◽  
Reaction Time ◽  
Ring Opening ◽  
Secondary Phase ◽  
Ring Opening Polymerization ◽  
Tem Analysis ◽  
No Formation ◽  
Waxs Pattern ◽  
The Impact ◽  
Effect Of Surface

In this study, surface modification of hydroxyapatite (HAp) by grafting polycaprolactone (PCL) is described. This method is carried out into two steps: (1) A treatment of HAp powder with a mixture of tetraorthosilicate (TEOS) and 3-aminopropyl-etriethoxysilane (APTES) to introduce amine groups and enhance nucleophilicity of surface functionalities; (2) Initiation of the Ring Opening Polymerization (ROP) of the ε-caprolactone (CL) in the presence of the silanized HAp. Moreover, the impact of the reaction time (24, 48 and 72 h) on the grafting amount of PCL is performed. The results of FTIR analysis confirmed the presence of carbonyl groups on the silanized HAp, providing evidence of grafting of PCL on the HAp surface. WAXS pattern showed no formation of a secondary phase after surface modification and the crystallinity is preserved. SEM/TEM analysis revealed a homogenous surface powder composed of irregular nanoscale crystals. TGA analysis indicated the dependence of PCL graft amount on the reaction time. Finally, the effect of surface modification on HAp/PCL nanocomposites morphology was investigated.

scholarly journals Investigation of redox switchable titanium and zirconium catalysts for the ring opening polymerization of cyclic esters and epoxides

2017 ◽  
Vol 4 (11) ◽  
pp. 1798-1805 ◽  
Author(s):  
Miranda Y. Lowe ◽  
Sisheng Shu ◽  
Stephanie M. Quan ◽  
Paula L. Diaconescu
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Synthesis And Characterization ◽  
Cyclic Esters ◽  
Zirconium Catalysts

The synthesis and characterization of (thiolfan*)Zr(OtBu)2 (thiolfan* = 1,1′-di(2,4-di-tert-butyl-6-thiophenoxide)ferrocene) is reported, as well as its activity toward the ring-opening polymerizations of l-lactide and ε-caprolactone.

scholarly journals Amphiphilic Nucleobase-Containing Polypeptide Copolymers—Synthesis and Self-Assembly

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1357
Author(s):  
Michel Nguyen ◽  
Khalid Ferji ◽  
Sébastien Lecommandoux ◽  
Colin Bonduelle
Keyword(s):  
Self Assembly ◽  
Ring Opening ◽  
Building Blocks ◽  
Ring Opening Polymerization ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Transmission Electron ◽  
Scattering Measurements ◽  
Thymidine Monophosphate ◽  
The Impact

Nucleobase-containing polymers are an emerging class of building blocks for the self-assembly of nanoobjects with promising applications in nanomedicine and biology. Here we present a macromolecular engineering approach to design nucleobase-containing polypeptide polymers incorporating thymine that further self-assemble in nanomaterials. Diblock and triblock copolypeptide polymers were prepared using sequential ring-opening polymerization of γ-Benzyl-l-glutamate N-carboxyanhydride (BLG-NCA) and γ-Propargyl-l-glutamate N-carboxyanhydride (PLG-NCA), followed by an efficient copper(I)-catalyzed azide alkyne cycloaddition (CuAAc) functionalization with thymidine monophosphate. Resulting amphiphilic copolymers were able to spontaneously form nanoobjects in aqueous solutions avoiding a pre-solubilization step with an organic solvent. Upon self-assembly, light scattering measurements and transmission electron microscopy (TEM) revealed the impact of the architecture (diblock versus triblock) on the morphology of the resulted nanoassemblies. Interestingly, the nucleobase-containing nanoobjects displayed free thymine units in the shell that were found available for further DNA-binding.

Synthesis and structures of N-arylcyano-β-diketiminate zinc complexes and adducts and their application in ring‐opening polymerization of l-lactide

RSC Advances ◽  
2015 ◽  
Vol 5 (27) ◽  
pp. 21054-21065 ◽  
Author(s):  
Oleksandra S. Trofymchuk ◽  
Constantin G. Daniliuc ◽  
Gerald Kehr ◽  
Gerhard Erker ◽  
Rene S. Rojas
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Metal Center ◽  
Zinc Complexes

The coordination of B(C6F5)3 molecule close to the metal center in new zinc Nacnac complexes affects the ROP of l-LA.

A single active site metal center of neodymocene chloride for the ring-opening polymerization of ε-caprolactone

2011 ◽  
Vol 123 (2) ◽  
pp. 1212-1217 ◽  
Author(s):  
Weifeng Hou ◽  
Jin Chen ◽  
Xiaoli Yan ◽  
Zuyun Shi ◽  
Junquan Sun
Keyword(s):  
Active Site ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Metal Center

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>

Confocal and SEM imaging to demonstrate food pathogen- biofilm biocontrol by pyocyanin from Pseudomonas aeruginosa BTRY1

2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Opportunistic Pathogens ◽  
Redox Active ◽  
Sem Imaging ◽  
The Impact

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

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
Sign in / Sign up

Export Citation Format

Share Document