Lanthanide Complexes with 1,4,7-Trimethyl-1,4,7-triazacyclononane

The reaction of 1,4,7-trimethyl-1,4,7-triazacyclononane with samarium, gadolinium, and terbium chloride tetrahydrofuranates gives mononuclear complexes [LnCl₃(Me₃tacn)(THF)_n] (Me₃tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane; Ln = Sm (I), Gd (II), n = 1; Ln = Tb (III), n = 0). The treatment of complexes I or II with 1,2,4-triphenylcyclopentadienyl potassium affords mono(cyclopentadienyl) co-mplexes [Cp^Ph3LnCl₂(Me₃tacn)] (Cp^Ph3 = 1,2,4-triphenylcyclopentadienyl; Ln = Sm (IV), Gd (V)). Complexes IV and V are formed even when a twofold excess of Cp^Ph3K is used. The molecular structure of complexes I–V was established by X-ray diffraction analysis (CCDC nos. 2299485 (I), 2299487 (II), 2299486 (III), 2305352 (IV), 2306051 (V)).