Unexpected High Second-Order Nonlinear Optical Activity of Metal Complexes with Three-Branched Hexadentate
Marie C Wolff1, Nick van Steerteghem2, Koen Clays2
1Department of Chemistry, University of Hamburg, Martin Luther King Platz 6, 20146, Hamburg, Germany.
Abstract:
Two hexadentate bipyridine ligands and their RuII and NiII complexes were prepared. The helical alignment of the three electron-donor-π-bridge-electron-acceptor (d-π-A) single-strands with bundle architecture in cooperation with the metal center can strongly enhance the nonlinear optical (NLO) properties. The complexation of the novel cage-type hexadentate ligands with a paramagnetic NiII -core almost doubles the βHRS values compared with the corresponding diamagnetic RuII complexes. The hyper-Rayleigh scattering (HRS) was performed with a highly sensitive setup for simultaneous discrimination between multi-photon fluorescence and the molecular first hyperpolarizability.
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