Synthesis and non-linear optical properties of (alkyne)dicobalt octacarbonyl complexes and their substitution derivatives
作者:In Su Lee、Dong Mok Shin、Yeohoon Yoon、Seok Min Shin、Young Keun Chung
DOI:10.1016/s0020-1693(02)01185-4
日期:2003.1
A series of new donor-acceptor compounds of the form [(HCdropC-CH=CH-C6H4-X-p)Co-2(CO)(4)(L-1)(L-2)])] (2, X = Br, L-1 = L-2 = CO; 3, X = NO2, L-1 = L-2 = CO; 6, X = NO2, L-1 = CO, L-2 = PPh3; 7, X = NO2, L-1 = L-2 = PPh3; 8, X = NO2, L-1 = AsPh3, L-2 = PPh3) where X is a pi-acceptor group and the (alkyne)Co-2(CO)(4)(L-1))(L-2) moiety is a donor, has been synthesized. The different sigma-donor/pi-acceptor abilities of the ligands L-1 and L-2 allow tuning of the electronic and optical properties of complexes 2, 3 and 6-8: the hyperpolarizability values increase in the order 2 < 3 < 6 < 7 < 8. Density functional calculations reveal that the absolute values of beta do not agree with experimental results, but the general trends are consistent with experiments. The X-ray crystal structures of 2, 6, and 7 are reported. (C) 2002 Elsevier Science B.V. All rights reserved.