doi:10.1016/S0040-4039(00)02338-8
Copyright © 2001 Elsevier Science Ltd All rights reserved.
Zinc(II)-operated intramolecular charge transfer fluorescence emission in pyrene-2,2′-bipyridine conjugated molecular rods
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Stéphanie Leroya, Tirapattur Soujanyaa and Frédéric Fages
, a, 
aLaboratoire de Chimie Organique et Organométallique, UMR 5802, Université Bordeaux 1, 33405, Talence Cedex, France
Received 24 July 2000;
accepted 19 December 2000.
Available online 15 February 2001.
Abstract
The design and synthesis of two conjugated pyrene-2,2′-bipyridine linear rods is described. Zn(II) ion complexation allows the formation of a highly polar emissive excited state through efficient photoinduced intramolecular charge transfer.
Synthesis and fluorescence emission properties of two conjugated molecular rods containing the pyrene and 2,2′-bipyridine units as termini are reported.
Keywords: fluorescence; polycyclic aromatic compounds; complexation; electron transfer; molecular devices
Scheme 1. (a) HC
C(CH3)2OH (1.2 equiv.), Et2NH, [PdII(PPh3)2Cl2] (2.5 mol%), CuI (1.5 mol%), 50°C, 20 h, 70%; (b) NaOH (excess), toluene, reflux, 2 h, 90%; (c) 3 (0.7 equiv.), Et2NH, [PdII(PPh3)2Cl2] (11 mol%), CuI (11 mol%), 50°C, 18 h, 90%; (d) NaOH (excess), toluene, reflux, 2 h, 80%; (e) 4-bromo-2,2′-bipyridine (1.1 equiv.), Et2NH, [PdII(PPh3)2Cl2] (7 mol%), CuI (15 mol%), 30°C, 20 h, 22%.
Figure 1. Corrected fluorescence emission spectra of the free ligand 1 in toluene, and of its Zn(II) complex in toluene and THF (ligand concentration: <10−6 M, metal concentration: 10−4 M, excitation 400 nm).
Table 1.
Selected photophysical data for compounds 1 and 2 and their Zn(II) complexes
a Absorption maxima.
b Fluorescence emission maxima.
c 637 nm in dichloroethane, 642 nm in butyronitrile.
d 595 nm in dichloroethane.
e Quenched emission.

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