Abstract
Reactions of anhydrous lanthanide trichlorides, LnCl3 (Ln = Nd, Sm, Ho), with 3 equiv. of lithium-cyclopropylethinylamidinates, Li[c-C3H5–CC–C(NR)2] (1a: R = cyclohexyl (Cy), 1b: R = iPr), afforded the new homoleptic lanthanide(III) tris(cyclopropylethinylamidinate) complexes [c-C3H5–C
C–C(NCy)2]3Sm (2a) and [c-C3H5–C
C–C(NiPr)2]3Ln (Ln = Nd (2b), Sm (2c), Ho (2d)) as air- and moisture-sensitive crystalline solids in moderate to good isolated yields (45–79%). The formation of unsolvated, homoleptic Ln(III) tris(cyclopropylethinylamidinate) was confirmed by an X-ray diffraction study of the holmium derivative [c-C3H5–C
C–C(NiPr)2]3Ho (2d). EI mass spectra of the new rare-earth metal amidinates indicated a significant volatility. An initial catalysis study revealed that these complexes catalyze the addition of terminal alkynes to carbodiimides to give propiolamidines of the type R–C
C–C(
NR′)(NHR′). The molecular structure of N,N′-dicyclohexyl-phenylpropiolamidine, Ph–C
C–C(NCy)(NHCy) (4), was also determined by X-ray diffraction.
- This article is part of the themed collection: Frontiers of Organo-f-Element Chemistry