Synthesis and structural characterization of a homoleptic cerium(III) propiolamidinate

The first potassium salt of a propiolamidinate ligand, K[PhCtriple bond; length of mdashC(NiPr)2] (1), was prepared in 51% yield by addition of potassium phenylacetylide to N,N′-diisopropylcarbodiimide. Subsequent reaction of 1 with anhydrous cerium(III) trichloride in a molar ratio of 3:1 in THF afforded the first homoleptic lanthanide tris(propiolamidinate) derivative, [PhCtriple bond; length of mdashC(NiPr)2]3Ce (2), in the form of bright yellow crystals in 71% yield.