Synthesis And Characterization Of Divalence Lanthanide Complexes Supported By Linked Bis(amidinate)s And Their Catalytic Properties

A series of lanthanide divalent complexes supported by linked bis(amidinate)s (L = [Me3SiNC(Ph)N(CH2)3NC(Ph)NSiMe3]) were synthesized and well characterized, including monometallic and bimetallic, as well as two divalent Eu cluster. The catalytic activity of these complexes for the addition reactions of amines with nitriles was tested. The main results obtained are as follows:1 Dilithium bis(amidinate)s LLi2 (1) was synthesize and well characterized including X-ray diffraction. Complex 1 can catalyze the amination reaction of amines with nitriles, but show lower activity than dilithium bis(amidenate)s divalent ytterbium cluster.2 Reaction of complex 1 with EuI2 in a 1:1 moral ratio in the presence of lithium oxide afforded the divalent bis(amidinate)s cluster [Li(DME)3+]2[{(EuI)2(μ2-I)2(μ3-L)2(Li)4}(μ6-O)]2- (2) and [Li(TMEDA)3+]2[{(EuI)2(μ2-I)2(μ3-L)2(Li)4}(μ6-O)]2- (3). These clusters were well characterized including X-ray diffraction, IR spectroscopy, and elemental analysis.3 The bis(amidinate)s Eu chloride formed in situ by the reaction of complex 1 with EuCl3 in a 1:1 moral ratio reacted with 1.15 eq of Na(K) alloys to afford a novel divalent bis(amidinete)s Eu cluster [{Eu2(μ2-Cl)2(μ3-L)2(Li)4}(μ6-O)] (4) constructed by Li2O and LiCl, in which the Li2O was formed by quantitative hydrolysis of LLi2 with H2O. This cluster was well characterized including X-ray diffraction, IR spectroscopy, and elemental analysis.4 Reaction of complex 1 with LnCl3 in a 1:1 moral ratio afforded the bis(amidinate)s chlorides LEuCl(TMEDA) (5) and LYbCl(THF)2. Complex 5 was well characterized including X-ray diffraction, IR spectroscopy, and elemental analysis. 5 The reaction of seperated LEuCl(TMEDA) (5) and LYbCl(THF)2 with 1.15 eq Na(K) alloys, respectively, afforded the divalent bis(amidinate)s lanthanide complexes(LEu)2 (6), and LYbYbCl2YbL (8) All these complexes were well characterized including X-ray diffraction, IR spectroscopy, and elemental analysis.6 Reaction of dilithium bis(amidenate)s LLi2 with EuCl3 in a 2:1 moral ratio afforded the bis(amidinate)s europium complex, which further reacted with 1.15 eq of Na(K) alloys gave the divalent bis(amidinate)s lanthanide complexe L2EuLi2(THF)2 (7). Complex 7 was well characterized by X-ray diffraction.