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ABAB homoleptic bis(phthalocyaninato)lutetium(III) complex: toward the real octupolar cube and giant quadratic
Mehmet Menaf Ayhan1, Anu Singh, Catherine Hirel
1Laboratoire de Chimie de l'ENS de Lyon, CNRS UMR 5182, Université Lyon I, ENS de Lyon, 46 allée d'Italie, 69364 Lyon cedex 07, France.
Abstract:
The concept of octupolar molecules has considerably enlarged the engineering of second-order nonlinear optical materials by giving access to 2D and 3D architectures. However, if the archetype of octupolar symmetry is a cube with alternating donor and acceptor groups at the corners, no translation of this ideal structure into a real molecule has been realized to date. This may be achieved by designing a bis(phthalocyaninato)lutetium(III) double-decker complex with a crosswise ABAB phthalocyanine bearing alternating electron-donor and electron-acceptor groups. In this communication, we present the first step toward this goal with the synthesis, crystal structure determination, and measurement of the molecular first-order hyperpolarizability β by harmonic light diffusion, of an original lutetium(III) sandwich complex displaying the required ABAB-type alternation for one face of the cube. This structure is characterized by an intense absorption in the near-IR due to an intervalence transition and exhibits the highest quadratic hyperpolarizability ever reported for an octupolar molecule, √<β(2)(HLS)> = 5750 × 10(-30) esu.
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