title: 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[nBuC(=NR)(NR)C(NR)2] [1:R= Cy (cyclo-hex-yl),2:R=iPr) were obtained by treatment ofN,N'-diorganocarbodi-imides,R-N=C=N-R(R=iPr, Cy), with 0.5 equivalents ofn-butyl-lithium under well-defined reaction conditions. An X-ray diffraction study of2revealed a ladder-type dimeric structure in the solid state. Reaction of anhydrous holmium(III) chloride within situ-prepared2afforded the unexpected holmium 'ate' complex [nBuC(=NCy)(NCy)C(NCy)2]Ho[nBuC(NCy)2](μ-Cl)2Li(THF)2(3) in 71% yield. An X-ray crystal structure determination of3showed that this complex contains both an amidinate ligand and the new amidino-guanidinate ligand.
authors.affiliation: Organometallic and Organometalloid Chemistry Department, National Research, Centre, 12622 Dokki, Cairo, Egypt.
authors.forename: Farid M
authors.initials: FM
authors.lastname: Sroor
authors.affiliation: Chemisches Institut der Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany.
authors.forename: Phil
authors.initials: P
authors.lastname: Liebing
authors.affiliation: Chemisches Institut der Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany.
authors.forename: Cristian G
authors.initials: CG
authors.lastname: Hrib
authors.affiliation: Chemisches Institut der Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Gräsing
authors.affiliation: Chemisches Institut der Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany.
authors.forename: Liane
authors.initials: L
authors.lastname: Hilfert
authors.affiliation: Chemisches Institut der Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany.
authors.forename: Frank T
authors.initials: FT
authors.lastname: Edelmann
keywords: amidinate ligands; amidino­guanidinate; crystal structure; guanidinate ligands; holmium; lithium