Copper(II) and Nickel(II) Complexes of a Tetradentate Ligand Containing an N,N′-Bis(Salicylidene)Dodecane-1, 10-Diamine Core

Abstract

The synthesis of mesomorphic Cu(II) and Ni(II) coordination compounds arising from a new series of tetradentate Schiff bases containing two salicylaldimine fragments connected by a very long spacer,-(CH₂)₁₂-, (H₂Lⁿ): L¹ = p-(C₆H₁₃O)-C₆H₄COO, L² = p-(C₁₂H₂₅O)-C₆H₄COO, is described. The self-assembly and liquid-crystalline properties of these complexes have been investigated by variable temperature powder X-ray diffraction and the relationship between the global molecular shape and the mesogenic performances is discussed. The reported Cu(II) compounds are molecular materials which could be of interest for applications in the field of magnetic molecule-based devices.

Keywords:

• Cu(II) and Ni(II) complexes
• metallomesogens
• salen-like Schiff bases

Acknowledgments

This work was partly supported by both the Ministero dell'Istruzione, dell'Università e della Ricerca through the Centro di Eccellenza CEMIF.CAL grant and by the Italian PRIN founding n. 2006038447.

Notes

^a Cr: crystal; Sm: smectic; N: nematic, I: isotropic liquid.

^b Temperature data as onset peak.

^a Cr: crystal; Sm: smectic; N: nematic, I: isotropic liquid.

^b Temperature data as onset peak. ^c Microscopic data.