DOI: 10.1002/chem.200700523 Novel Core-Expanded Rylenebis(Dicarboximide) Dyes Bearing Pentacene Units: Facile Synthesis and Photophysical Properties Yuri Avlasevich, [a] Sibylle Müller, [a] Peter Erk, [b] and Klaus Müllen* [a] Introduction Rylenebis(dicarboximide) chromophores 1 possess excep- tional chemical, thermal and photochemical stabilities with high extinction coefficients. [1] Their use has been explored for demanding applications such as optoelectronic [2] and photovoltaic [3] devices, thermographic processes, [4] energy- transfer cascades, [5] light-emitting diodes [6] and NIR-absorb- ing systems. [7] Extension of the aromatic system along the long molecular axis from perylene- (PDI), 1a (n = 0), to ter- rylene- (TDI), 1b (n = 1) [8] and quaterrylenebis(dicarboxi- mide)s (QDI), 1c (n = 2) [9] induced a bathochromic shift of about 100 nm per additional naphthalene unit reaching an absorbance maximum of 780 nm for the quaterrylene 1c and a nearly linear increase of the extinction coefficient up to 170000 m À1 cm À1 . Very recently, the syntheses of two higher rylene homologues, which each have an intensive ab- sorption in the NIR region, were reported: pentarylene- (1d, n = 3, l max = 877 nm) and hexarylenebis(dicarboximide)s (1e, n = 4, l max = 950 nm). [10] Abstract: Two synthetic routes for the benzannulation in the “bay”-region of rylenebis(dicarboximide)s leading to new p-system-expanded chromophores are described. The first route follows a two-step approach: Suzuki coupling of bromo-substituted perylenebis(dicar- boximide) with 2-bromophenylboronic acid, followed by palladium-catalysed dehydrobromination. The second route is best described as a palladium-assist- ed cycloaddition of benzyne, formed in situ, to the bay-region of the bromo- substituted rylene core. Two new types of core-expanded rylene dyes were syn- thesised: yellow dibenzocoronenebis- ACHTUNGTRENNUNG(dicarboximide)s, absorbing at 490 nm, and a green dinaphthoquaterrylenebis- ACHTUNGTRENNUNG(dicarboximide), which absorbs at 700 nm. These new chromophores are characterised by significant hypsochro- mic shifts of absorption, compared to their parent rylenebis(dicarboximide)s, excellent photostabilities and high fluo- rescence quantum yields. Keywords: absorption · benzannu- lation · dyes/pigments · fluores- cence · perylenes · quaterrylene [a] Dr. Yu. Avlasevich, Dr. S. Müller, Prof.Dr. K. Müllen Max Planck Institute for Polymer Research Ackermannweg 10, 55128 Mainz (Germany) Fax: (+ 49)6131-379350 E-mail: muellen@mpip-mainz.mpg.de [b] Dr. P. Erk BASF Aktiengesellschaft 67056 Ludwigshafen (Germany) Chem. Eur. J. 2007, 13, 6555–6561 # 2007 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim 6555 FULL PAPER