| Publication Type |
Journal Article |
| Title |
Compromise between conjugation length and charge-transfer in nonlinear optical eta(5)-monocyclopentadienyliron(II) complexes with substituted oligo-thiophene nitrile ligands: Synthesis, electrochemical studies and first hyperpolarizabilities |
| Authors |
M. Helena Garcia Paulo Mendes M Paula Robalo A. Romao Dias Jochen Campo Wim Wenseleers Etienne Goovaerts |
| Groups |
BIOIN BIOMOL |
| Journal |
JOURNAL OF ORGANOMETALLIC CHEMISTRY |
| Year |
2007 |
| Month |
June |
| Volume |
692 |
| Number |
14 |
| Pages |
3027-3041 |
| Abstract |
A systematic series of eta(5)-monocyclopentadienyliron(II) complexes with substituted oligo-thiophene nitrile ligands of general formula [FeCp(P\_P)(NC\SC4H2\(n)NO2)] [PF6] (P\_P = dppe, (+)-diop; n = 1-3) has been synthesized and characterized. The electrochemical behaviour of the new compounds was explored by cyclic voltammetry. Quadratic hyperpolarizabilities (beta) of the complexes with dppe coligands have been determined by hyper-Rayleigh scattering (HRS) measurements at two fundamental wavelengths of 1.064 and 1.550 mu m, to uncover the two-photon resonance effect and to estimate static beta values. The obtained overall results are found to be better than for the related eta(5)-monocyclopentadienyliron(II) complexes with p-benzonitrile derivatives. Although an increase of the resonant beta at 1.064 mu m with increasing number of thiophene units in the conjugated ligand was found (up to 910 x 10(-30) esu), the static values beta(0) remain practically unchanged, as shown by the 1.550 mu m measurements. Combined with the electrochemical and spectroscopic data (IR, NMR, UV-vis), this remarkable evolution of beta shows that the increase of conjugation length is balanced by a decrease in charge-transfer efficiency. (C) 2007 Published by Elsevier B.V. |
| DOI |
http://dx.doi.org/10.1016/j.jorganchem.2007.03.023 |
| ISBN |
|
| Publisher |
ELSEVIER SCIENCE SA |
| Book Title |
|
| ISSN |
0022-328X |
| EISSN |
|
| Conference Name |
|
| Bibtex ID |
ISI:000248028700018 |
| Observations |
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