Synthesis of New Multifunctional Polymers inCorporating BIS-(Diphenylamino)Diphenylpolyene Moieties
- PDF / 289,503 Bytes
- 7 Pages / 414.72 x 648 pts Page_size
- 9 Downloads / 175 Views
Mat. Res. Soc. Symp. Proc. Vol. 488 © 1998 Materials Research Society
3
Zn
POC1 3
Ti11s
0 2
CHO MND-N
CHO 1. CO
4
+
S•'
,Br3 H2PBu NaOEI 2. H30 f THF 1. LAH 2. Ph3P / Br2 3. (EtO)3P
O
•
CH2PO(OEQ) 2
0
KOt-Bu THF
N
K 6
Scheme 1. Preparation of bis-(diphenylamino)stilbene and bis-(diphenylamino)diphenylbutadiene
284
comparing these results to those previously obtained for the bis-(N,N-dimethylamino)diphenyl polyene series',". Table 1. Oxidative doping of 4', 4"-disubstituted diphenylpolyenes
X•
Im. BP (nm)3
n
x
3 4 5 6 7 8
Ph 2N Ph 2N Ph 2N Ph 2N Ph 2N Ph 2N
424 438 449 462 464 485
730 770 805 848 892 922
3 4 5 6
Me 2N Me 2N Me 2N Me 2N
410 425 445 458
b b 714 752
a 10M solutions in CH 2C12 ;
(ic-ir*) neutral (nm)"
'not stable
INCORPORATION OF BIS-(DIPHENYLAMINO)DIPHENYLPOLYENE PENDANT CHROMOPHORES ON PMMA Bis-(diphenylamino)diphenylpolyenes functionalized for attachment to PMMA can be readily synthesized, as outlined in Scheme 3, followed by attachment to poly(methacroyl chloride. Quenching of the residual COCI groups with excess MeOH yields the substituted PMMA. This approach eliminates variations in polymer properties due to differing chain lengths attached to monomer (methyl methacrylate) and then polymerized. We also believe that this approach gives a more uniform, though random, distribution of the pendant groups on the chain. This procedure is outlined in Scheme 4. POTENTIAL APPLICATIONS We have recently shown, in collaboration with coworkers at Laser Photonics Technology, that polyene type molecules may function as optical power limiters via reverse saturable absorption based on photogeneration of highly stable bipolarons'6 . It has also recently been shown by Perry and coworkers that bis-(diphenylarnino)stilbene is an extremely good 2-photon absorberaT. In addition, we are currently studying 2-photon absorption in dithienylpolyenes in collaboration with the Laser Hardening Group at Wright Labs (MLPJ), and have recently shown the 1,8-dithienyl-1,3,5,7-octatetraene has a very large 2-photon cross-section"8 . The bisdiphenylamino)diphenylpolyenes reported in this study thus represent a potentially new class of optical power limiting materials, whether in solution, formulated as guest-host composites or as functionalized polymers (e.g. PMMA). These materials have the unique capability of providing optical limiting and eye protection via two distinctly different mechanisms: (1) at the higher end of the visible energy range by photogeneration of highly absorbing bipolarons (RSA), and (2) via two-photon absorption (TPA) at the lower end of the visible energy range. We believe that this is the first such broad-band bimechanistic optical limiting that has been proposed, and the materials
285
~CH=CH)mCHO
M
600
+-
+
Bu3PCH 2(CH=CH)pCH 2PBu 3 , 2Br N1 NaOEt / EtOH / DMF or
KOt-Bu / THF
m = 0,1,2 ..... p= 1,2 n = 2m + p + 2
Scheme 2. Preparation of bis-(diphenylamino)diphenylpolyenes
NO M
Na
CH2OH Ac2O
CH2OAc
0DMF POC13
•
N-YCH
4 HOCH 2
KI•-Bu
[CHO
Scheme 3. Pr
Data Loading...
