Abstract
Treatment of the lithiated amidinate ligand Li[HC(NDmp)2] (Dmp = 2,6-dimethylphenyl) with 2 equiv of NiI2 afforded the dinickel complex Ni2(I)2 (µ-I)2(µ-κ2-HC(NDmp)2) Li(THF)2(OEt2)2 (1). However, reaction of the amidinato Li[HC(NDmp)2] ligand with 0.5 equiv of NiI2 resulted in the formation of the lantern-type dinuclear complex, Ni2[(µ-κ2-HC(NDmp)2]3 (2). Subsequent reduction of 1 by KC8 resulted in the isolation of the dinickel bisamidinate compound Ni2[(µ-κ2-HC(NDmp)2]2 (4). Compound 4 can be alternatively prepared by reaction of 1 with 1 equiv of Li[HC(NDmp)2] and then 4 equiv of KC8. The later route produced 4 with a better yield. Moreover, reaction of 1 with Li[HC(NDipp)2] (Dipp = 2,6-diisopropylphenyl) and 4 equiv of KC8 furnished the unprecedented low-coordinate heteroleptic dinickel complex Ni2(µ-κ2-HC(NDmp)2)(µ-κ2-HC(NDipp)2) (5). Reaction of 1 with Li[HC(NDep)2] (Dep = 2,6-diethylphenyl) and 4 equiv of KC8 generated three products, which are the heteroleptic complex Ni2(µ-κ2-HC(NDmp)2)(µ-κ2-HC(NDipp)2) and two homoleptic dinickel compounds [Ni(µ-κ2-HC(NDmp)2)]2 and [Ni(µ-κ2-HC(NDep)2)]2. Unfortunately, we cannot separate the heteroleptic species Ni2(µ-κ2-HC(NDmp)2)(µ-κ2-HC(NDipp)2 from the other two homoleptic compounds. In the second part of this thesis, reaction of the amidinate ligand Li[HC(NDmp)2] with anhydrous FeCl2 or CoCl2 produced the cyclic tetrairon complex, [Fe(µ-Cl)(µ-κ2-HC(NDmp)2)]4 (8) and the “ate” dicobalt complex Co2(Cl)(µ-Cl)[κ1-ClLi(THF)3][µ-κ2-HC(NDmp)2]2 (12), respectively. KC8 reduction of 8 or 12 led to the formation of the lantern complex M2[(µ-κ2-HC(NDmp)2)]3 (9: M = Fe; 13: M = Co). When the slightly more steric hindered amidinate ligand (Li[HC(NDep)2]) was employed to react with anhydrous FeCl2 and CoCl2, the lantern type complexes, Fe2[(µ-κ2-HC(NDep)2]3 (11) and Co2[(µ-κ2-HC(NDep)2]3 (15) are also the major products.