Ionic Complexes Of Conjugated Oligoquinolines
- PDF / 355,279 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 86 Downloads / 195 Views
H190 9
o-
n
-
-
H19
n'
R = aromatic groups BuN-PPQ (2).PSSA (3) complex Precise control over the molecular and supramolecular organizations of these polymeric materials could enhance the efficiency and overall performance of the devices they are incorporated in [7]. One of the methods that exemplifies this approach is the construction of layer-by-layer thin films by consecutively alternating adsorption of oppositely charged polyelectrolytes from dilute solutions [8,9]. The advantage of this
563
Mat. Res. Soc. Symp. Proc. Vol. 488 © 1998 Materials Research Society
method is that the thickness and supramolecular architecture of thin films could be controlled very precisely. Multilayer thin film materials have been successfully fabricated in this way with a large variety of polymers, such as conjugated [10] and non-conjugated [8,9] polyions, conjugated polymer precursors [11,12], and p-type doped conducting polymers [7]. We have recently used this method for the construction of bilayer films of polyquinoline, poly(2,2'-(p-phenylene)-6,6'-bis(3-nonyl-4-(p-tert-butyl phenyl)quinoline)) (BuN-PPQ, 2), and polystyrenesulfonic acid (PSSA, 3) [13]. This was accomplished by dipping thin films of the polyquinoline into a dilute solution of PSSA in methanol. The sulfonic acid groups of 3 formed an acid-base complex with the imine nitrogens of the polyquinoline leading to the adsorption of PSSA onto the polyquinoline layer. This adsorption was monitored using optical absorption and photoluminescence spectroscopies. The photoluminescence emission efficiency of the polyquinoline/PSSA complex was enhanced by over one order of magnitude, suggesting that such complexes are promising candidates for incorporation into optoelectronic devices. To gain a better understanding of the polyquinoline/PSSA complex and quarternized polyquinolines in general, on a molecular and supramolecular level, we initiated investigation of complexes of oligoquinolines with various sulfonic acids. Results for oligoquinoline 2,2'-bis(4-phenylquinoline)-l,4-phenylene (4) which is the model for polyquinoline and its complexes are reported here. Photophysical studies and X-ray structures of single crystals of these complexes together with their photophysical properties provide a good basis for understanding the molecular structure and properties of the polyquinoline complexes in particular and polyelectrolyte complexes in general. To our knowledge, this comprises the first such study. p-toluenesulfonic acid /methanol -
/N
// N/4
trifluorosulfonic acid /methanol
p-toluenesulfonate salt 5
0
Sulforhodamine 101
hydrate/methanol
trifluorosulfonate salt
6
sulforhodarnine salt 7
EXPERIMENTAL SECTION Materials. All the starting materials were obtained from Aldrich and used as received. The oligoquinoline 4 was synthesized by condensing 2-aminobenzophenone and 1,4diacetylbenzene in a m-cresol:diphenylphosphate mixture [14]. It was recrystallized from a Sulfonate salts were prepared by dissolving methanol/THF mixture prior to use. stoichiometric amou
Data Loading...
