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Transition metal catalysts play a prominent role in modern organic and polymer chemistry, enabling many transformations of academic and industrial significance. However, the use of organometallic catalysts often requires the removal of their residues from reaction products, which is particularly important in the pharmaceutical industry. Therefore, the development of efficient and economical methods for the removal of metal contamination is of critical importance. Herein, we demonstrate that commercially available 1,4-bis(3-isocyanopropyl)piperazine can be used as a highly efficient quenching agent ( QA ) and copper scavenger in Cu/TEMPO alcohol aerobic oxidation (Stahl oxidation) and atom transfer radical polymerization (ATRP). The addition of QA immediately terminates Cu-mediated reactions under various conditions, forming a copper complex that can be easily separated from both small molecules and macromolecules. The purification protocol for aldehydes is based on the addition of a small amount of silica gel followed by QA and filtration. The use of QA@SiO2 synthesized in situ results in products with Cu content usually below 5 ppm. Purification of polymers involves only the addition of QA in THF followed by filtration, leading to polymers with very low Cu content, even after ATRP with high catalyst loading. Furthermore, the addition of QA completely prevents oxidative alkyne–alkyne (Glaser) coupling. Although isocyanide QA shows moderate toxicity, it can be easily converted into a non-toxic compound by acid hydrolysis. 

Abstract A facile and efficient two‐step synthesis ofp‐substituted tris(2‐pyridylmethyl)amine (TPMA) ligands to form Cu complexes with the highest activity to date in atom transfer radical polymerization (ATRP) is presented. In the divergent synthesis,p‐Cl substituents in tris(4‐chloro‐2‐pyridylmethyl)amine (TPMA^3Cl) were replaced in one step and high yield by electron‐donating cyclic amines (pyrrolidine (TPMA^PYR), piperidine (TPMA^PIP), and morpholine (TPMA^MOR)) by nucleophilic aromatic substitution. The [Cu^II(TPMA^NR2)Br]⁺complexes exhibited larger energy gaps between frontier molecular orbitals and >0.2 V more negative reduction potentials than [Cu^II(TPMA)Br]⁺, indicating >3 orders of magnitude higher ATRP activity. [Cu^I(TPMA^PYR)]⁺exhibited the highest reported activity for Br‐capped acrylate chain ends in DMF, and moderate activity toward C−F bonds at room temperature. ATRP ofn‐butyl acrylate using only 10–25 part per million loadings of [Cu^II(TPMA^NR2)Br]⁺exhibited excellent control. 

Abstract The first well‐controlled aqueous atom‐transfer radical polymerization (ATRP) conducted in the open air is reported. This air‐tolerant ATRP was enabled by the continuous conversion of oxygen to carbon dioxide catalyzed by glucose oxidase (GOx), in the presence of glucose and sodium pyruvate as sequential sacrificial substrates. Controlled polymerization using initiators for continuous activator regeneration (ICAR) ATRP of oligo(ethylene oxide) methyl ether methacrylate (OEOMA,M_n=500) yielded polymers with low dispersity (1.09≤Đ≤1.29) and molecular weights (MWs) close to theoretical values in the presence of pyruvate. Without added pyruvates, lower MWs were observed due to generation of new chains by H₂O₂formed by reaction of O₂with GOx. Successful chain extension of POEOMA₅₀₀macroinitiator with OEOMA₃₀₀(Đ≤1.3) and Bovine Serum Albumin bioconjugates (Đ≤1.22) confirmed a well‐controlled polymerization. The reactions in the open air in larger scale (25 mL) were also successful. 

Abstract Atom transfer radical polymerization (ATRP) can be carried out in a flask completely open to air using a biocatalytic system composed of glucose oxidase (GOx) and horseradish peroxidase (HRP) with an active copper catalyst complex. Nanomolar concentrations of the enzymes and ppm amounts of Cu provided excellent control over the polymerization of oligo(ethylene oxide) methyl ether methacrylate (OEOMA₅₀₀), generating polymers with high molecular weight (M_n>70 000) and low dispersities (1.13≤Đ≤1.27) in less than an hour. The continuous oxygen supply was necessary for the generation of radicals and polymer chain growth as demonstrated by temporal control and by inducing hypoxic conditions. In addition, the enzymatic cascade polymerization triggered by oxygen was used for a protein and DNA functionalized with initiators to form protein‐b‐POEOMA and DNA‐b‐POEOMA bioconjugates, respectively. 

Abstract Efficient heterogeneous photosensitizing materials require both large accessible surface areas and excitons of suitable energies and with well‐defined spin structures. Confinement of the tetracationic cyclophane (ExBox⁴⁺) within a nonporous anionic polystyrene sulfonate (PSS) matrix leads to a surface area increase of up to 225 m²g⁻¹in ExBox•PSS. Efficient intersystem crossing is achieved by combining the spin‐orbit coupling associated to Br heavy atoms in 1,3,5,8‐tetrabromopyrene (TBP), and the photoinduced electron transfer in a TBP⊂ExBox⁴⁺supramolecular dyad. The TBP⊂ExBox⁴⁺complex displays a charge transfer band at 450 nm and an exciplex emission at 520 nm, indicating the formation of new mixed‐electronic states. The lowest triplet state (T₁, 1.89 eV) is localized on the TBP and is close in energy with the charge separated state (CT, 2.14 eV). The homogeneous and heterogeneous photocatalytic activities of the TBP⊂ExBox⁴⁺, for the elimination of a sulfur mustard simulant, has proved to be significantly more efficient than TBP and ExBox⁺⁴, confirming the importance of the newly formed excited‐state manifold in TBP⊂ExBox⁴⁺for the population of the low‐lying T₁state. The high stability, facile preparation, and high performance of the TBP⊂ExBox•PSS nanocomposites augur well for the future development of new supramolecular heterogeneous photosensitizers using host–guest chemistry.