The pseudo-octahedral molybdenum benzylidyne complex [TolC≡Mo(ONO)(OR)]·KOR (R = CCH3(CF3)2) 1, featuring a stabilizing ONO pincer ligand, initiates the controlled living polymerization of strained dibenzocyclooctynes at T > 60 °C to give high molecular weight polymers with exceptionally low polydispersities (PDI ∼ 1.02). Kinetic analyses reveal that the growing polymer chain attached to the propagating catalyst efficiently limits the rate of propagation with respect to the rate of initiation (kp/ki ∼ 10(-3)). The reversible coordination of KOCCH3(CF3)2 to the propagating catalyst prevents undesired chain-termination and -transfer processes. The ring-opening alkyne metathesis polymerization with 1 has all the characteristics of a living polymerization and enables, for the first time, the controlled synthesis of amphiphilic block copolymers via ROAMP.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4308759 | PMC |
| http://dx.doi.org/10.1021/ja510919v | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Sustainable Synthesis of Substituted 1,3,5-Triazines by [ONO]-Pincer-Supported Nickel(II) Complexes via an Acceptorless Dehydrogenative Coupling Strategy.
J Org Chem
December 2024
Department of Crystallography, Institute of Chemistry, University of Silesia, 40-006 Katowice, Poland.
A facile, cost-effective, and sustainable synthesis of substituted triazines from primary alcohols by newly synthesized nickel pincer-type complexes (-) has been described. Herein, we report the synthesis of a set of three well-defined Ni(II) O^N^O pincer-type complexes, structurally characterized by analytical, spectral, and X-ray diffraction techniques. Further, the nickel complexes are explored as efficient catalysts (4 mol %) for the construction of 2,4,6-substituted 1,3,5-triazines from readily available alcohols via an acceptorless dehydrogenative coupling (ADC) strategy.
View Article and Find Full Text PDFUtility of Interchangeable Coordination Modes of ,'-Dialkyl-2,6-pyridinediamide Tridentate Pincer Ligands for Solvent Extraction of Pd(II) and Zr(IV) from High-Level Radioactive Liquid Waste.
Inorg Chem
December 2024
Laboratory for Zero-Carbon Energy, Institute of Integrated Research, Institute of Science Tokyo, 2-12-1 N1-32, O-okayama, Meguro-ku 152-8550, Tokyo, Japan.
A new class of ligands, ,'-dialkyl-2,6-pyridinediamide (DRPDA), has been designed with the specific intention of exhibiting interchangeable diversity in coordination modes, including organometallic interactions, for the purpose of solvent extraction of elements relevant to the proper treatment of high-level radioactive liquid waste (HLLW) generated after nuclear fuel reprocessing. Consequently, DRPDA has been observed to extract Pd(II) and Zr(IV) from HNO(aq) to 1-octanol in nearly quantitative yields when the selected ligand is sufficiently hydrophobic. However, concomitance of some of other HLLW components were also found.
View Article and Find Full Text PDFMn(III) O^N^O Complexes as Water-tolerant and Environmentally Benign Catalysts for Polyurethane Foam Synthesis.
Chemistry
March 2024
Catalysis Research Laboratory (CaRLa), University of Heidelberg University, Im Neuenheimer Feld 584, 69120, Heidelberg, Germany.
Polyurethanes are synthesized on industrial scale by the reaction of diisocyanates with diols in the presence of catalysts which are commonly based on tin complexes and amines. However, due to the toxicity and volatility of these tin catalysts and amines, there is the need to develop new catalysts that are more environmentally benign. Herein, we report the synthesis of O^N^O pincer-ligated Mn(III) and Fe(III) complexes that serve as suitable catalysts for urethane formation and are stable to hydrolysis as predicted by computations and observed experimentally.
View Article and Find Full Text PDFSynthesis and structure of Pd(II) pincer complexes: catalytic application in β-alkylation of secondary alcohols involving sequential dehydrogenation of alcohols the borrowing hydrogen approach.
Dalton Trans
July 2023
Centre for Organometallic Chemistry, School of Chemistry, Bharathidasan University, Tiruchirappalli - 620 024, Tamilnadu, India.
Herein, we report an efficient and sustainable approach for the selective synthesis of ketones by palladium pincer catalyzed β-alkylation of secondary alcohols with aromatic primary alcohols the borrowing hydrogen (BH) approach for the first time. A set of new Pd(II) ONO pincer complexes was synthesized and characterised by elemental analysis and spectral techniques (FT-IR, NMR and HRMS). The solid-state molecular structure of one the complexes was corroborated by X-ray crystallography.
View Article and Find Full Text PDFPlatinum Assisted Tandem P-C Bond Cleavage and P-N Bond Formation in Amide Functionalized Bisphosphine -PhPCHC(O)N(H)CHPPh-: Synthesis, Mechanistic, and Catalytic Studies.
Inorg Chem
January 2022
Phosphorus Laboratory, Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
The reactions of amide functionalized bisphosphine -PhPCHC(O)N(H)CHPPh- () with platinum salts are described. Treatment of with [Pt(COD)Cl] yielded a chelate complex, [PtCl{-PhPCHC(O)N(H)CHPPh-}] (), which on subsequent treatment with LiHMDS formed a novel 1,2-azaphospholene-phosphine complex [Pt(CH)Cl{-CH{C(O)N(-PPh(CH))P(Ph)}}] () involving a tandem P-C bond cleavage and P-N bond formation. The same complex on passing dry HCl gas afforded the dichloro complex [PtCl{-CH{C(O)N(-PPh(CH))P(Ph)}}] ().
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!