An effi cient way for covering various surfaces with poly(lactic acid) (PLA) is discussed. In a fi rst step, the material is coated with polydopamine (PDA) by air oxidation of dopamine. The resulting PDA layer acts as an initiator for ring-opening polymerization (ROP) of lactide resulting in an outer PLA shell. Since PDA sticks to almost every solid material, the methodology has a wide scope. The strategy is demonstrated with magnetic nanoparticles and non-magnetic powders.can be achieved by ring-opening polymerization (ROP) of lactide in the presence of the material to be covered. There are materials where PLA does not stick or the adhesion is not strong enough. In such cases, a primary adhesive coating is advised that anchors to the material to be covered on the one hand and binds the PLA on the other hand. The most effi cient linkage of PLA is achieved when covalent bonds are formed by surface-initiated ROP. Here, nucleophilic reactive groups at the surface initiate the ROP and fi x the growing PLA chain covalently. In this way, magnetite NPs (MNPs) stabilized by glycolic acid were treated with lactide in the presence of tin(II) 2-ethylhexanoate under microwave conditions. [ 13 ] In a similar manner, MNPs covered with oleic acid underwent a ligand exchange by ω-hydroxy carboxylic acids and were subsequently covered with PLA by tin dioctanoatecatalyzed ROP of L -lactide. [ 14 ] In both cases, the PLA shell anchors by the help of the carboxylate groups of the initial ω-hydroxycarboxylic acid. Since anchoring of carboxylate to magnetite is not very strong and thus reversible, the search for better primary coverage of MNPs is still desired. Furthermore, the application of poisonous tin dioctanoate causes limitations if biomedical applications are considered. In an alternative approach, MNPs were stabilized by glyceryl phosphate or ascorbyl phosphate and then treated with lactide in the presence of 4-( N , N -dimethylamino)pyridine (DMAP). [ 15 ]

In polyfl uorenes it is generally accepted that (photo)degradation leads to fl uorenone type defects that accept the excitation energy and emit green-toyellow light with rather low effi ciency. Although initial spectroscopic studies suggest the same to hold true for ladder-type poly( para -phenylene)s (LPPPs), kinetic studies of the degradation process are not compatible with the established mechanism. In general, the observed green emission can be caused by the introduction of carbonyl groups; however, only if associated with an additional disruption of the backbone rigidity and hence planarity of the entire π-system. This is clearly shown by comparison with synthesized model compounds, which are bearing the fl uorenone motif yet possess very different optical properties as compared to the defects, which are actually formed. Degradation can be caused by solvent specifi c, yet substrate nonspecifi c aromatic formylation but mainly originates from reaction with in-situ generated singlet oxygen, both in solution as well as in thin fi lms. Time-dependent photoluminescence measurements on thin fi lms show that green emission is enhanced by energy transfer from intact molecules to defect centers.

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Nitro compounds Q 0100 (S)-Pyrrolidin-2-ylmethyl-1,2,3-triazolium Salts -Ionic Liquid Supported Organocatalysts for Enantioselective MichaelAdditions to β-Nitrostyrenes. -Chiral triazolinium salts (Ia) or (Ib) can used as catalysts in enantioselective Michael additions to nitrostyrenes in excess of carbonyl compounds as reactant and as solvent. -(YACOB, Z.; SHAH, J.; LEISTNER, J.; LIEBSCHER*, J.; Synlett 2008, 15, 2342-2344; Inst. Chem.,