The synthesis of 0 th (n = 1) and 1 st (n = 2) generation, monodisperse, star-shaped oligoviologens, C[(BnV ++ -PhV ++ ) n -CH 2 X] 3 , which consist of a phenyl or a 2,4,6-trimethylphenyl core (C) with triple 1,3,5-branches, in which each branch consists of a linear alternating series of diphenyl-(PhV ++ ) and dibenzyl viologens (BnV ++ ) and a variety of peripheral groups X (CH 3 , OH, Br), is described. According to MM+ modeling, the stars adopt a flat structure with the branches pointing towards the corners of an equilateral triangle with a centre-corner distances of 2.9 (n = 1) and 5.8 nm (n = 2, repulsive charge interaction). Discrete redox chemistry from the benzyl-(-0.27, -0.70 V) and phenyl viologen subunits (-0.12, -0.42 V vs. Ag/AgCl) is observed as a set of four interdigitated reduction waves, which involve 3 ϫ 4 = 12 (0 th generation) and 3 ϫ 8 = 24 electrons (1 st generation) as shown by

The synthesis and characterization of two types of viologen polymer modification of semiconducting carbon nanotubes (poly‐I‐CNT and poly‐II‐CNT) are described. The monomer I is a large three‐arm star‐shaped compound consisting of three benzyl and three phenyl viologen subunits. Electrochemical polymerization via benzylic radical formation was used. The star arms in poly‐I‐CNT are well‐resolved structures in two‐dimensional crystallized fashion (from STM), pointing to self‐assembling prior to polymerization. Besides being completely surface covered, individual SWCNTs are interconnected with the polymer in the poly‐I‐CNT composite material. Poly‐II‐CNT was prepared by chemical reduction of N′‐methyl‐N‐aminophenyl viologens. Repetitive viologen oligomer brushes are observed along the SWCNT after polymerization. The functionalization is confirmed by XPS, electrochemistry, and Raman spectroscopy.

The cover picture shows the synthesis of new star‐shaped oligoviologens (left to right), consisting of a trifold central branching unit and three linear branches (up to 5.8 nm long) of alternating benzyl (blue) and phenyl viologens (red). Up to 24 electrons can be injected into the viologen subunits at four well‐separated electrode potentials (green vertical region). The corresponding localized spin densities in a single short branch are shown in the grey region. Viologen stars with peripheral benzylic bromides are reductively cross‐linked to yield a polymer with persisting star subunits (brown region). The star‐shaped multielectron molecules are supposed to have potential applications as electron sponges, as switchable organic magnets, as nanometer‐sized components in composite nanomaterials, and so on. Details are discussed in the article by L. Walder et. al. on p. 913 ff.