New Lanthanide Alkynylamidinates and Diiminophosphinates

Farid Sroor, Cristian Hrib, Frank Edelmann
2015 Inorganics  
This contribution reports the synthesis and structural characterization of several new lithium and lanthanide alkynylamidinate complexes. Treatment of PhC≡CLi with N,N′-diorganocarbodiimides, R-N=C=N-R (R = i Pr, Cy (cyclohexyl)), in THF or diethyl ether solution afforded the lithium-propiolamidinates Li[Ph-C≡C-C(NCy)2] S (1: R = i Pr, S = THF; 2: R = Cy, S = THF; 3: R = Cy, S = Et2O). Single-crystal X-ray diffraction studies of 1 and 2 showed the presence of typical ladder-type dimeric
more » ... ype dimeric structures in the solid state. Reactions of anhydrous LnCl3 (Ln = Ce, Nd, Sm or Ho) with 2 in a 1:3 molar ratio in THF afforded a series of new homoleptic lanthanide tris(propiolamidinate) complexes, [Ph-C≡C-C(NCy)2]3Ln (4: Ln = Ce; 5: Ln = Nd; 6: Ln = Sm; 7: Ln = Ho). The products were isolated in moderate to high yields (61%-89%) as brightly colored, crystalline solids. The chloro-functional neodymium(III) bis(cyclopropylethynylamidinate) complex [{c-C3H5-C≡C-C(N i Pr)2}2Ln(µ-Cl)(THF)]2 (8) was prepared from NdCl3 and two equiv. of Li[c-C3H5-C≡C-C(N i Pr)2] in THF and structurally characterized. A new monomeric Ce(III)-diiminophosphinate complex, [Ph2P(NSiMe3)2]2Ce(µ-Cl)2Li(THF)2 (9), has also been synthesized in a similar manner from CeCl3 and two equiv. of Li[Ph2P(NSiMe3)2]. Structurally, this complex resembles the well-known "ate" complexes (C5Me5)2Ln(µ-Cl)2Li(THF)2. Attempts to oxidize compound 9 using trityl chloride or phenyliodine(III) dichloride did not lead to an isolable cerium(IV) species. OPEN ACCESS Inorganics 2015, 3 430
doi:10.3390/inorganics3040429 fatcat:zau4negytbbffp3bhcfqkowpgq