Oxygen-Enhanced Atom Transfer Radical Polymerization through the Formation of a Copper Superoxido Complex.

In controlled radical polymerization, oxygen is typically regarded as an undesirable component resulting in terminated polymer chains, deactivated catalysts, and subsequent cessation of the polymerization. Here, we report an unusual atom transfer radical polymerization whereby oxygen favors the polymerization by triggering the transformation of CuBr/L to reactive superoxido species at room temperature. Through a superoxido ARGET-ATRP mechanism, an order of magnitude faster polymerization rate and a rapid and complete initiator consumption can be achieved as opposed to when unoxidized CuBr/L was instead employed.

Manipulating electron transfer - the influence of substituents on novel copper guanidine quinolinyl complexes.

Copper guanidine quinolinyl complexes act as good entatic state models due to their distorted structures leading to a high similarity between Cu(i) and Cu(ii) complexes. For a better understanding of the entatic state principle regarding electron transfer a series of guanidine quinolinyl ligands with different substituents in the 2- and 4-position were synthesized to examine the influence on the electron transfer properties of the corresponding copper complexes. Substituents with different steric or electronic influences were chosen.

Influence of the amine donor on hybrid guanidine-stabilized Bis(μ-oxido) dicopper(III) complexes and their tyrosinase-like oxygenation activity towards polycyclic aromatic alcohols.

The tyrosinase-like activity of hybrid guanidine-stabilized bis(μ-oxido) dicopper(III) complexes [Cu(μ-O)(L)](X) (L = 2-{2-((Diethylamino)methyl)phenyl}-1,1,3,3-tetramethylguanidine (TMGbenzNEt, L2) and 2-{2-((Di-isopropylamino)methyl)phenyl}-1,1,3,3-tetramethylguanidine (TMGbenzNiPr, L3); X = PF, BF, CFSO) is described. New aromatic hybrid guanidine amine ligands were developed with varying amine donor function. Their copper(I) complexes were analyzed towards their ability to activate dioxygen in the presence of different weakly coordinating anions.

Photoluminescence of Fully Inorganic Colloidal Gold Nanocluster and Their Manipulation Using Surface Charge Effects.

Fully inorganic, colloidal gold nanoclusters (NCs) constitute a new class of nanomaterials that are clearly distinguishable from their commonly studied metal-organic ligand-capped counterparts. As their synthesis by chemical methods is challenging, details about their optical properties remain widely unknown. In this work, laser fragmentation in liquids is performed to produce fully inorganic and size-controlled colloidal gold NCs with monomodal particle size distributions and an fcc-like structure.

Conductance-strain behavior in silver-nanowire composites: network properties of a tunable strain sensor.

Highly flexible and conductive nano-composite materials are promising candidates for stretchable and flexible electronics. We report on the strain-resistance relation of a silver-nanowire photopolymer composite during repetitive stretching. Resistance measurements reveal a gradual change of the hysteretic resistance curves towards a linear and non-hysteretic behavior.