Preparation of Chromophoric Dipolar Dendrons as Second-Order Nonlinear Optical Material
- PDF / 397,619 Bytes
- 6 Pages / 414.72 x 648 pts Page_size
- 104 Downloads / 153 Views
Mat. Res. Soc. Symp. Proc. Vol. 488 ©1998 Materials Research Society
H3 YH3
(CH2)14
0•0,
i -
ON0 oOH
AO
O. O No
"N
.,H
HO'I'-.N%
0•"•
Ng
0to0 ,oC
,N
H CH,
0
0ýJ
cN02 N
NC 0
H
,N
N
N" o
qH3 ICH3 (CHA)14 ( z)4 (C•HZ)14
(CA4(cH2)14,
9H, (CH2)14
OME EM
2
ii
0
OR
3; R=CH 2OCH 2 CH 2OCH 3 (MEM)
((m/z 2138, caled for [M+HJI 2129.9) 4; R=H (m/z 2049, caled for [M+Hl+ 2041.8) I
iii
iv
v
(m/z 4543, calcd for [M+Na]+ 4530.8) 5; R=M\EM 6; R=H (m/z 4439, caled for [M+Nal+ 4442.6)
7 (m/z 9311, calcd for [M+Na]+ 9288.7)
Scheme 1 Preparation of dendrons. Reagents and conditions: i, iii, and v, DCC, DMAP, CH 2 CI 2 , 20'C; ii and iv, HCI, THF, 0-5°C. The m/z values were measure by MALDI TOFMS.
766
"13CNMR spectroscopy after purification by column chromatography. SEC showed the highly purity levels and narrow monodispersity of molecular weights, M/Mn8000x10 31,esu for dendron 7. The dendron/chromophore hyperpolarizability ratio was found to be 9.5. These SHG experimental results supported our synthesis strategy that chromophores were organized in the dendritic structure to form a rodshaped conformation in these films rather than the spreading conformation, so products predicted a large increase in the nonlinear optical activity compared with the individual chromophore. The SHG results presented here provided a conclusive demonstration that the rod-shaped dendritic material enhanced its molecular hyperpolarizability through a noncentrosymmetric arrangement of functional units in a branching structure. REFERENCES 1. A. Ulman, S. C. S. Willand, W. Kdhler, D. R. Robello, D. J. Williams, and L. Handley, J. Am. Chem. Soc., 112, p. 7083 (1990). 2. P. N. Prasad and D. J. Williams, Introduction to Nonlinear Optical Effects in Molecules and Polymers, Wiley, New York, 1991. 3. G. Marowsky and R Steinhoff, Opt. Lett. 13, p. 707 (1988). 4. G. Marowsky, L. F. Chi, D. Mobuis, R. Steinhoff, Y. R. Shen, D. Dorsch, and B. Rieger, Chem. Phys. Lett., 147, p. 420 (1988). 5. D. Lupo, W. Prass, U. Scheunemann, A. Laschewsky, Helmut Ringsdorf, and I. Ledoux, J. Opt. Soc. Am. B, 5, p. 300 (1988). 6. M. Kauranen, T. Verbiest, C. Boutton, M. N. Teerenstra, K. Clays, A. J. Schouten, R. J. M. Nolte, and A. Persoons, Science, 270, p. 966 (1995). 7. S. Yokoyama, T. Nakahama, A. Otomo, ans S. Mashiko, Chem. Lett., p. 1,137 (1997). 8. M. A. Carpenter, C. S. Willand, T. L. Penner, D. J. Williams, and S. Mukamel, J. Phys. Chem., 96, p. 2801 (1992). 9. Y. R. Shen, Nature, 337, p. 519 (1989). 10. H. E. Katz, G. Scheller, T. M. Putvinski, M. L. Schilling, W. L. Wilson, and C. E. D. Chidsey, Science, 254, p. 1485 (1991). 11. D. Li, B. I. Swanson, J. M. Robinson, and M. T. Hoffbauer, J. Am. Chem. Soc., 115, p. 6975 (1993). 12. G. Marowsky, G. Liipke, R. Steinhoff, L. F. Chi, and D. M6bius, Phys. Rev. B., 41, 4480 (1990). 13. T. G. Zhang, C. H. Zhang, and G. K. Wong, J. Opt. Soc. Am. B, 6, p. 902 (1990). 14. 1. R. Girling, N. A. Cade, P. V. Kolinsky, R. J. Jones, I. R. Peterson, M. M. Ahmad, D. B. Neal, M. C. Petty, G. G. Roberts,
Data Loading...
