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Many attempts to upgrade polystyrene have been made in the past. One of the last and most popular examples is the upgrading of polystyrene by stereo-controlled polymerization of styrene monomer, yielding a syndiotactic material. But the property profile of polystyrene can also be improved by stiffening the polymer chain with bulky groups. 1,1-Diphenylethylene (DPE) was selected as a monomer with such a bulky group and was copolymerized anionically with styrene to give an amorphous copolymer with a statistical chain structure which was called 'super-polystyrene'. In this paper the conditions of the anionic polymerization and the properties of the resulting materials are described. Depending on the DPE content, the glass transition temperature can be varied from 104°C to 180°C. Up to a DPE content of 15%, these styrene-DPE copolymers are miscible with GPPS as well as with syndiotactic polystyrene. Toughening of the transparent polymers was achieved with glass fibers and grafted rubber particles. Block copol...

RP groups are useful cluster constituents: They warrant a detailed analysis of cluster reactions even in those cases where metal-metal bonds break and where, without these linking groups, the clusters would desintegrate.

The chemistry of RP-bridged clusters may be interpreted in terms of coordinatively stabilized antiaromatic organometallic 4π ligands. The idea of regarding these 4π entities (cf. A – C) as the central constituents of clusters is a synthetically rewarding approach.