First Homoleptic Rare Earth Carbazolates: Synthesis,Crystal Structures,Spectroscopic and Thermal Investigations of Divalent 1[Ln(NC12H8)2] with Ln = Europium and Ytterbium

The compounds [Ln(NC₁₂H₈)₂], Ln = Eu and Yb, were obtained in solvent free reactions of the rare earth elements europium and ytterbium with the amine carbazole. Single crystals of both compounds were grown from the melt syntheses, no recrystallization from solvents was necessary. The new compounds are the first examples of homoleptic carbazolates of the rare earth elements furthermore exhibiting divalent lanthanides. In absence of any solvent, carbazole as the sole coordination partner shows η⁶‐π‐coordination in addition to the μ₁‐ and μ₂‐coordination of the nitrogen atoms. This results in a one‐dimensional chain structure of dimers with a formal C.N. of 6 for the rare earth elements and thus being low for divalent lanthanides. The products were investigated by X‐ray single crystal and powder diffraction, Mid IR, Far IR and Raman spectroscopy, and with DTA/TG regarding their thermal behaviour. Both compounds [Ln(NC₁₂H₈)₂], Ln = Eu (1) and Yb (2) , crystallize isotypic in the triclinic space group P1.