400 research outputs found
Copper(0)-mediated radical polymerisation in a self-generating biphasic system
Herein, we demonstrate the synthesis of well-defined poly(n-alkyl acrylate)s via copper(0)-mediated radical polymerisation in a self-generating biphasic system. During the polymerisation of n-butyl acrylate in DMSO, the polymer phase separates to yield a polymer-rich layer with very low copper content (ICP-MS analysis: 0.016 wt%). The poly(n-butyl acrylate) has been characterized by a range of techniques, including GPC, NMR and MALDI-TOF, to confirm both the controlled character of the polymerisation and the end group fidelity. Moreover, we have successfully chain extended poly(n-butyl acrylate) in this biphasic system several times with n-butyl acrylate to high conversion without intermediate purification steps. A range of other alkyl acrylates have been investigated and the control over the polymerisation is lost as the hydrophobicity of the polymer increases due to the increase in alkyl chain length indicating that it is important for the monomer to be soluble in the polar solvent
Crystal Structure of Orthorhombic {bis-[(pyridin-2-yl)methyl](3,5,5,5-tetrachloropentyl)amine-Îş\u3csup\u3e3\u3c/sup\u3e\u3cem\u3eN,N\u27,N\u27\u27\u3c/em\u3e}chloridocopper(II) Perchlorate
In the title compound, [CuCl(C17H19Cl4N3)]ClO4, the CuII ion adopts a distorted square-planar geometry defined by one chloride ligand and the three nitroÂgen atoms from the bisÂ[(pyridin-2-yl)methÂyl](3,5,5,5-tetraÂchloroÂpentÂyl)amine ligand. The perchlorate counter-ion is disordered over three sets of sites with refined occupancies 0.0634 (17), 0.221 (16) and 0.145 (7). In addition, the hetero-scorpionate arm of the bisÂ[(pyridin-2-yl)methÂyl](3,5,5,5-tetraÂchloroÂpentÂyl)amine ligand is disordered over two sets of sites with refined occupancies 0.839 (2) and 0.161 (2). In the crystal, weak Cuâ‹ŻCl interÂactions between symmetry-related molÂecules create a dimerization with a chloride occupying the apical position of the square-pyramidal geometry typical of many copper(II) chloride hetero-scorpionate complexes
Sequential ATRA/Reductive Cyclopropanation Reactions with a Ruthenium Catalyst in the Presence of Manganese
Ruthenium vs. Osmium Complexes as Catalysts for Atom Transfer Radical Addition Reactions
Aminoarenethiolato-copper(I) as (pre-)catalyst for the synthesis of diaryl ethers from aryl bromides and sequential C–O/C–S and C–N/C–S cross coupling reactions
ChemInform Abstract: Atom Transfer Radical Addition and Polymerization Reactions Catalyzed by ppm Amounts of Copper Complexes
ChemInform Abstract: “Greening” of Copper Catalyzed Atom Transfer Radical Addition (ATRA) and Cyclization (ATRC) Reactions
ChemInform Abstract: Catalyst Regeneration in Transition-Metal-Mediated Atom-Transfer Radical Addition (ATRA) and Cyclization (ATRC) Reactions
Crystal structure of ammonium bis[(pyridin-2-yl)methyl]ammonium dichloride
In the title molecular salt, C12H14N3+·NH4+·2Cl-, the central, secondary-amine, N atom is protonated. The bis[(pyridin-2- yl)methyl]ammonium and ammonium cations both lie across a twofold rotation axis. The dihedral angles between the planes of the pyridine rings is 68.43 (8)°. In the crystal, N-H⋯N and N-H⋯Cl hydrogen bonds link the components of the structure, forming a two-dimensional network parallel to (010). In addition, weak C-H⋯Cl hydrogen bonds exist within the two-dimensional network
Equilibrium Constants and Activation Rate Coefficients for Atom Transfer Radical Polymerizations at Pressures up to 2 500 Bar
- …