Formation and structure of the first metal complexes comprising amidino-guanidinate ligands.

ABSTRACT: The first metal complexes comprising amidino-guanidinate ligands have been prepared and structurally characterized, namely bis-[μ-N,N',N'',N'''-tetraisopropyl-1-(1-butyl-amidinato)guanidinato-κ³N¹,N²:N²]bis-[(tetra-hydro-furan)lithium], [Li₂(C₁₈H₃₇N₄)₂(C₄H₈O)₂], (2), and [bis-(tetra-hydro-furan)-lithium]-di-μ-chlorido-{(N,N'-di-cyclo-hexyl-1-butyl-amidinato-κ²N¹,N²)[N,N',N'',N'''-tetra-cyclo-hexyl-1-(1-butyl-amidinato)guanidinato-κ²N¹,N²]holmate(III)}, [HoLiCl₂(C₄H₈O)₂(C₁₇H₃₁N₂)(C₃₀H₅₃N₄)], (3). The novel lithium amidino-guanidinate precursors Li[ ⁿ BuC(=NR)(NR)C(NR)₂] [1: R = Cy (cyclo-hex-yl), 2: R = ⁱ Pr) were obtained by treatment of N,N'-diorganocarbodi-imides, R-N=C=N-R (R = ⁱ Pr, Cy), with 0.5 equivalents of n-butyl-lithium under well-defined reaction conditions. An X-ray diffraction study of 2 revealed a ladder-type dimeric structure in the solid state. Reaction of anhydrous holmium(III) chloride with in situ-prepared 2 afforded the unexpected holmium 'ate' complex [ ⁿ BuC(=NCy)(NCy)C(NCy)₂]Ho[ ⁿ BuC(NCy)₂](μ-Cl)₂Li(THF)₂ (3) in 71% yield. An X-ray crystal structure determination of 3 showed that this complex contains both an amidinate ligand and the new amidino-guanidinate ligand.

SUBMITTER: Sroor FM 

PROVIDER: S-EPMC5095825 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature