Perylene-bromine

Since the discovery of the first organic semiconductor perylene-bromine complex in 1954 [1], a large number of molecular conductors, including more than 100 molecular superconductors, have been prepared. Conducting molecular materials are characterized by the following features ... 

Akamatsu, H., H. Inokuchi, and Y. Matsunaga. 1954. Electrical conductivity of the perylene-bromine complex. Nature 173 168. 

Perylene is one of the oldest donors used in the preparation of highly conducting oiganic solids, and its use dates back at least to the 1954 report, by Akamatu et al. [1], of the conducting perylene-bromine complexes. As in the case of many other molecular... 

Similarly, Torres et al. also reported the preparation of perylene-Pc assemblies 5 (Fig. 5). The synthesis of these triads was thereby accomplished via palladium-catalyzed cross-coupling pursuing two different routes [46], First preparing the perylenediimide with two bromine units in positions 1 and 7 and subsequent... 

The first indication that molecular compounds could exhibit interesting electrical properties apart from those of an insulator was given in 1954, when Akamatu et al. (1) reported a resistivity of p = 10 2 cm for a bromine salt of perylene. Normally perylene crystals themselves are insulating with p = 1014 1016 1 cm therefore, a dramatic change in electronic structure had occurred. The perylene molecule is shown in Fig. 1. 

Two approaches were available for the preparation of quaterrylene bisimides, taking advantage of either intramolecular cyclization or intermolecular dimerization reactions. These two methods were developed independently in Mullen s and Langhals groups. As shown in Scheme 7, Mullen s intramolecular approach started from bromination of perylene monoimide 74, which was subjected to Yamamoto coupling reaction to produce precursor 76, and the quaterrylene bisimide 77 was... 

Typical for perylene and many other n-systems is the relatively high energy of the highest occupied molecular orbital (HOMO). Typical for the bromine molecule, on the other hand, is the low energy of the lowest unoccupied molecular orbital (LUMO). Therefore, in the experiment of Akamatu et al., a Mulliken charge transfer complex is formed between perylene and bromine, where perylene is the electron donor (D) and bromine is the acceptor (A). 

Two important polycycles produced prior to 1920 were perylene 19 (Fig. 1.2a) and pyrene 7, both of note as parent structures for numerous fused benzenoid analogs produced in the following decades. In 1910, Scholl, Seer, and Weitzenbock first produced perylene from an AlCls-mediated cyclization of naphthalene and/or 1,1 -binaphthyl under heat in low yield [19]. A subsequent success with improved yield occurred via treatment of 1,8-diiodonaphthalene with Cu powder. Weitzenbock was responsible for the first synthesis of pyrene in 1913 [20]. The five-step synthesis began with bromination of o,o -ditolyl followed by conversion into dicar-boxylic add 20 via a dinitrile intermediate (Scheme 1.7). Cyclization and Zn-dust distillation afforded the tetra-fused structure in a well-designed synthesis, confirming its structure through intermediate analysis. 

Although far from presenting the lowest oxidation potential among many other known 7t-donors, the perylene molecule can be oxidised in several organic solvents, either by the direct action of chemical oxidants such as iodine or bromine, or electrochemi-cally. In dichloromethane solutions, at a potential of 0.9 V versus SCE (saturated calomel electrode), it... 

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