Perylene monoimide

Quite differently, Pleux et al. tested a series of three different organic dyads comprising a perylene monoimide (PMI) dye linked to a naphthalene diimide (NDI) or C60 for application in NiO-based DSSCs (Fig. 18.7) [117]. They corroborated a cascade electron flow from the valance band of NiO to PMI and, finally, to C60. Transient absorption measurements in the nanosecond time regime revealed that the presence of C60 extends the charge-separated state lifetime compared to just PMI. This fact enhanced the device efficiencies up to values of 0.04 and 0.06% when CoII/m and P/Ij electrolytes were utilized, respectively. More striking than the efficiencies is the remarkable incident photon-to-current efficiency spectrum, which features values of around 57% associated to photocurrent densities of 1.88 mA/cm2. 

Margineanu, A., Hotta, J., Auweraer, M. V. D., Ameloot, M., Stefan, A., Beijonne, D., Engleborghs, Y., et al. 2007. Visuahzation of membrane rafts using a perylene monoimide derivative and fluorescence hfetime imaging. Biophys. J. 93 2877-91. 

A typical example involves the perylene monoimide donors described above. They have been used to construct antenna models in which up to eight perylene units were covalently bound to a zinc(II) porphyrin94. Osuka and coworkers windmill porphyrins also present excellent antenna complex building blocks (vide infra)95. In addition, several porphyrin wheel antenna complexes were prepared by template-assisted synthesis96,97 or self-aggregation98. Intramolecular cyclization of porphyrin dodecamers to a porphyrin wheel has also been achieved99. 

Thus, the Yamamoto coupling of monobrominated perylene monoimide 71 provided N-alkyl and N-arylbiperylenyls 72 in 83-89% yield. In contrast... 

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... 

Similarly, the Diels-Alder reaction of M-alkylated perylene monoimide 84 with lV-pentadecyl-l,2,4-triazoline-3,5-dione 82 in boiling xylene yields the T-shaped, thermally as well as photochemically stable, blue perylene imide mesogens 85, see Scheme 4.23 [157]. The low reactivity of 84 and poor stability of 82 require the addition of a large excess (ten equivalents) of 82 in several portions to a solution of 84 in refluxing m-xylene to achieve 85 in good yield. 

Several methods have been reported for the monofunctionaUzation of PDI [6] including one-pot imidization (route A) or a base-promoted coupling reaction between naphthalene monoimide derivatives (route B) [7], as shown in Scheme 2. We found the one-pot imidizatitMi reaction (route A) to be more practical than route B route B consisted of five steps and the open-form product 6b was labile under the basic reaction conditions required to produce the closed product 6a. The one-pot imidization, route A, was simple and 3 could easily be recovered via column chromatography because the use of an excess amount of 3 was necessary. Concerning the solubility and reactivity of perylene tetracarboxylic acid dianhydride (PDA) 4, the imidization of 4 was, first, carried out with 2,6-ditsopropylaniline (5) in imidazole then 3 in propionic acid solution was added to produce the closed product PDI 6a. 

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