A novel methodology for photoinduced metal-free Atom Transfer Radical Polymerization (ATRP) by using conventional Type II photoinitiators such as benzophenone, thioxanthone, isopropyl thioxanthone and camphorquinone as sensitizers is presented.

Photoinduced metal-free atom transfer radical polymerization (ATRP) activated by highly conjugated electron-rich thienothiophene derivatives, namely 4-[2-(4-diphenylaminophenyl)-thieno­[3,2-b]­thiophen-3-yl]­benzonitrile (TT-TPA), 4-[2,5-bis­(4-diphenylaminophenyl)-thieno­[3,2-b]­thiophen-3-yl]­benzonitrile (TPA-TT-TPA), 4-(2-(4-(1,2,2-triphenylvinyl)­phenyl) thieno­[3,2-b]­thiophen-3-yl)­benzonitrile (TT-TPE) and 4-(2,5-bis­(4-(1,2,2-triphenylvinyl)­phenyl)­thieno­[3,2-b]­thiophen-3- yl)­benzonitrile (TPE-TT-TPE) is reported. Polymerization of methyl methacrylate (MMA) is efficiently activated and deactivated with light, forming polymers with controlled the molecular weight characteristics, dispersity, and chain end functionality. Polymerization studies and DFT calculations revealed that TT-TPA is the most efficient activator due to the favorable thermodynamic properties.

The present trend article reports on the recent progress of the in situ synthesis of polymer/clay nanocomposites with well‐defined structures and highly exfoliated morphologies. The methods used for the preparation are classified according to the individual polymerization mechanisms. Other possibilities such as multi‐mode polymerization that combines different polymerization methods and click chemistry are also described. A special emphasis is devoted to the structures and morphologies of the obtained nanocomposites rather than their practical properties.magnified image

The combination of equimolar amounts of LiOAr and Mg(OAr)2 (OAr=aryloxide) in polar media afforded several lithium aryloxomagnesiates. Factors influencing the structural chemistry of the compounds, such as the degree of ligand bulk, type of Lewis base donors, and crystallization solvent, are examined. Structural characterization reveals a discrete, solvent-separated species, [Li(thf)4][Mg(BHT)3].THF (1) (BHT=2,6-tBu2-4-MeC6H2O) and a family of molecular compounds with various Li/Mg stoichimetries, including a 1:1 Li/Mg ratio in [LiMg(Odpp)3(thf)2].0.5PhMe (2) (Odpp=2,6-Ph2C6H3O) and [Li(Et2O)Mg(Odpp)3].0.5PhMe (3), a 2:1 Li/Mg ratio as in [{Li(thf)2}2Mg(OMes)4].2THF (4) (OMes=2,4,6-Me3C6H2O) and [{Li(tmeda)}2Mg(m-Odtp)4].0.5Et2O (5) (m-Odtp=3,5-tBu2C6H3O), and a novel 2:3 Li/Mg ratio in [{Li(thf)2}2Mg3(m-Odtp)8(thf)2].3THF (6). Two new homometallic magnesium bis(aryloxides), Mg(Odpp)2(thf)2 (7) and Mg(Odpp)2(Et2O)2 (8), are also included for the sake of comparison. The solution behavior of the heterobimetallic compounds in arene and polar solvent is analyzed by 1H NMR spectroscopy.