NEW ORGANIC LIGANDS FOR NONLINEAR OPTICAL COMPLEXES

Abstract

The search for organometallic compounds with nonlinear optical (NLO) properties has becoming a field of considerable interest due to their potential as materials with technological applications in the area of nonlinear optical phenomena [1]. In the organometallic push-pull systems, the metal center behaves as an electron-acceptor or electron-donating center bonded to an organic delocalized pi-electron system. Organic compounds could present themselves NLO properties due to the high electronic polarizability of their .-system [1]. The ability to introduce subtle changes in the chemical structures, leading to improvements in their properties, and to build structureproperty relationships, make the organic compounds still good candidates for electronics and optical phenomena investigation area [1,2]. Here, we present the synthesis and spectroscopic characterization of electronwithdrawing organic ligands, suitable for coordination to electron donating Fe or Ru metal centers. These ligands present a two aromatic rings backbone linked by a spacer (double, triple or hydrazone bond) with one or two electron withdrawing nitro groups on para and ortho positions of the second aryl ring (Figure 1). The substitution with a nitrile or alkyne groups provide an available site for coordination to the metals. The structures of several compounds were confirmed by X-Ray diffraction studies.