Synthesis of Pyrene-Anthracene Conjugated Molecular Rods

Abstract

Fully conjugated pyrene-anthracene-based molecular rods were synthesized by the Horner-WadsworthEmmons reaction utilizing potassium tert-butoxide in dry THF. The synthesized rods, which have butylene groups as solubility spacers in the main chain, exhibited good solubility in polar solvents. The solutions of the synthesized pyrenecontaining molecular rods exhibited a blue shift in the UV-vis from the absorption maximum due to the presence of the pyrene group in comparison with the dialdehydes. The chemical structure and purity of the synthesized rods were confirmed by 1 H and 13 C NMR, FAB+, MALDI-TOF, electrospray mass spectra and elemental analysis.Keywords: Molecular rods, Horner-Wadsworth-Emmons, anthracene, pyrene.The presence of charge-transfer reaction centers in macromolecules depends on factors as the composition, the separation in the interchromophore, the overall dynamical and supramolecular reorganization, and the electronic coupling [1]. The synthesis of artificial charge-transfer model systems in which the introduction of simple molecular changes is used to control and tune the magnitude of the electrontransfer parameters became a theme of great interest in the last years. The molecular chains or bridges inside the molecule provide endless opportunities, since they determine the structural features and the size of the electronic coupling between the donor and acceptor fragments [2]. The modification of the spacer gives the possibility to introduce a systematic alteration of separation, orientation, and overlap without affecting the electronic nature of the donor-acceptor pair, for which the coupling is proportional to the overlap of their electronic clouds [3]. The electron-transfer processes depend on molecular size and structure, as well as the temperature and the free-energy difference between the donor and acceptor in donor-bridge-acceptor systems. Currently, monodisperse and soluble -conjugated systems with a well-defined length and composition are receiving a growing interest for the design of molecular wires [4] and rods [5], since they can be used as tunable building blocks [6] for nanoscale chemi-*Address correspondence to these authors at the Instituto de Química, Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, C.P. 04510, México D.F., México; E-mail: margar@servidor.unam.mx cal entities in molecular and supramolecular electronic and photonic devices [7]. In this context, the combination of anthracene and styrene with pyrene compounds could lead to systems with good response in the electron-transfer processes [8].In the present work, we describe the synthesis of a new series of compounds in which pyrene is linked to a vinyl anthracene and oligo(phenylvinylene)anthracene. These conjugated block oligomers with well defined structure and donor-bridge array were synthesized by Heck and HornerWadsworth-Emmons reactions using aromatic mono vinyl aldehydes, dialdehydes and diphosphonates as monomers. RESULTS AND DISCUSSIONThe synthesis of the monovinyl and divinyl...

Synthesis and characterization of a ruthenium-containing copolymer for use as a photoredox catalyst

“…S10†). Absorption peaks were observed at wavelengths of 329, 344, and 457 nm, which are similar to those observed in pyrenemethanol (328 and 344 nm) 31 and [Ru(bpy) 2 (dmbpy)](PF 6 ) 2 (455 nm). 32 We investigated the photophysical properties of each of the Ru( ii ) species used in this study, namely, poly[Ru(bpy) 2 (dmbpy)(PF 6 ) 2 - co -pyrene- co -MMA], poly[Ru(bpy) 2 (dmbpy)(PF 6 ) 2 - co -MMA], [Ru(bpy) 2 (dmbpy)](PF 6 ) 2 , and [Ru(bpy) 2 (dmbpy-MMA)](PF 6 ) 2 .…”

Synthesis and Optical Properties of Double Antenna Pyrene-OPV- Fullerene C60

“…For example, a series of structurally well-defined arrays that (1-pyrenyl methyl)phosphonate 8 by reducing first the commercially available aldehyde 5 with LiAlH 4 to afford 1-pyrene-methanol 6 that was later halogenated with thionyl chloride to give 1-chloromethyl-pyrene 7. This latter, upon treatment with P(OEt) 3 according to reaction conditions described in literature (14,16), yielded 8 (Scheme 2). The Horner-Wadsworth-Emmons reaction between an equivalent of dialdehyde terminated trimer 4 and an equivalent of diethyl(1-pyrenyl methyl)phosphonate 8 in THF and tert-BuOK gave aldehyde-OPV-pyrene derivative 8 in 38% yield and the corresponding di-substituted OPV-pyrene as by-product (Scheme 3), which was easily separated by chromatography on silica.…”