Foley Stephen R, Yap Glenn P A, Richeson Darrin S
Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
Inorg Chem. 2002 Aug 12;41(16):4149-57. doi: 10.1021/ic020088c.
Trisubstitued N,N',N' '-tri(alkyl)guanidinate anions have been used in the synthesis of a family of Fe(II) and Fe(III) complexes. Complexes FeCl((i)PrN)(2)C(HN(i)Pr) (1), Fe[micro-((i)PrN)(2)C(HN(i)Pr)][((i)PrN)(2)C(HN(i)Pr)] (2), and Fe[mgr;-(CyN)(2)C(HNCy)][(CyN)(2)C(HNCy)] (3) were prepared from the reaction of the appropriate lithium tri(alkyl)guanidinate and FeCl(3) or FeBr(2). The complex FeBr[micro-(CyN)(2)C(HNCy)] (4), an apparent intermediate in the formation of 3, has also been isolated and characterized. Complexes 1 and 2 react with alkyllithium reagents to yield products that depend on the identity of the reagent as well as the reaction stoichiometry. Reaction of 2 with MeLi (1:2 ratio) produces Li(2)Fe[micro-((i)PrN)(2)C=N(i)Pr][((i)PrN)(2)C(HN(i)Pr)] (5). Reaction of 1 with an equimolar amount of LiCH(2)SiMe(3) results in reduction to Fe(II) and generation of 2 while reaction with 4 LiCH(2)SiMe(3) proceeds by a combination of reduction, substitution, and deprotonation of guandinate to yield Li(4)(THF)(2)Fe((i)PrN)(2)CN(i)Pr(2) (7). Both complexes 5 and 7 posssess dianionic guanidinate ligands. The reaction of 2 with 1 equiv of LiCH(2)SiMe(3) generated Fe(2)[micro-((i)PrNCN(i)Pr)(2)(N(i)Pr)]((i)PrN)(2)C(HN(i)Pr) (6). Compound 6 has a dianionic biguanidinate ligand derived from the coupling of the two bridging guanidinate ligands of 2.
