Structural study of metallomesogens derived from tris-[2-(salicylideneamino)ethyl]amine. A molecular meccano

Abstract

The synthesis of new metal complexes based on imines derived from tris-(2-aminoethyl)amine (TREN) which exhibit different geometries depending on the metal [Cu(II), VO(IV), Pd(II), Ni(II), Ln(III)] has been carried out. TREN has three coordination positions which allow us to obtain different coordination complexes involving one, two or three metallic centres. The molecular structure and purity of these novel compounds have been verified by IR, 1H and 13C NMR and elemental analysis and electro-spray mass spectrometry. The phase behaviour was studied by polarizing optical microscopy, differential scanning calorimetry (DSC) and X-ray diffraction techniques. It was found that the transition metal complexes display a smectic C mesophase whereas the lanthanide complexes display an unidentified smectic mesophase.