New Rare Earth(III) Complexes with H₂tmtaa

A series of Ln(tmtaa)(Htmtaa)·CH₂Cl₂ (Ln=Sm, Tb, Er and Yb) complexes were prepared and characterized by infrared spectra, mass spectra and molecular electronic spectroscopy as well as DSC measurement. A sandwich structure containing all the eight nitrogen atoms of tmtaa and Htmtaa was proposed for these complexes. X-ray photoelectron spectra (XPS) of these complexes revealed that four nitrogen atoms of both tmtaa and Htmtaa were chemically equivalent to each other, respectively. The acidic hydrogen of Htmtaa did not bind specifically to any nitrogen atom of Htmtaa, but was shared by all the four nitrogen atoms. The magnetic properties of these complexes were found to be in good agreement with their theoretical values.