Preparation, Characterization, and Magnetic Behavior of the Ln Derivatives (Ln = Nd, La) of a 2,6-Diiminepyridine Ligand and Corresponding Dianion

An unprecedented Nd[2,6-{[2,6-(i-Pr)(2)C6H5]N=C(CH3)}(2)(C5H3N)]Ndl(2)(THF) (1) complex was prepared by oxidizing metallic Nd with 12 in THF and in the presence of 2,6-{[2,6-(i-Pr)(2)C6H5]N=C(CH3)}(2)(C5H3N). The magnetic behavior at variable T clearly indicated that the complex should be regarded as a trivalent Nd atom antiferromagnetically coupled to a radical anion. By using the doubly deprotonated form of the diimino pyridine ligand {[2,6-{[2,6-(i-Pr)(2)C6H5]N-C=CH2}(2)(C5H3N)](2-) (2) the corresponding trivalent complexes {[2,6-{[2,6-(i-Pr)(2)C6H5]N-C=CH2}(2)(C5H3N)]Ln (THF)}(mu-Cl)(2)[Li(THF)(2)].0.5 (hexane) [Ln = Nd (3), La (4)] were obtained and characterized. Reduction of these species afforded electron transfer to the ligand system which gave ligand dimerization via C-C bond formation through one of the two ene-amido functions of each molecule. The resulting dinuclear {[{[2,6-(i-Pr)(2)C6H5]N-C=(CH2)}(C5H3N){[2,6-(i-Pr)(2)C6H5]N=CCH2}]Ln(TH F)(2)(mu-CI)[Li(THF)(3)]}(2).2(THF) [Ln = Nd (5), La (6)] were isolated and characterized.