2162-74-5Relevant articles and documents
Copper(I) Complexes of Zwitterionic Imidazolium-2-Amidinates, a Promising Class of Electroneutral, Amidinate-Type Ligands
Márquez, Astrid,ávila, Elena,Urbaneja, Carmen,álvarez, Eleuterio,Palma, Pilar,Cámpora, Juan
, p. 11007 - 11017 (2015)
The first complexes containing imidazolium-2-amidinates as ligands (betaine-type adducts of imidazolium-based carbenes and carbodiimides, NHC-CDI) are reported. Interaction of the sterically hindered betaines ICyCDIDiPP and IMeCDIDiPP [both bearing 2,6-diisopropylphenyl (DiPP) substituents on the terminal N atoms] with Cu(I) acetate affords mononuclear, electroneutral complexes 1a and 1b, which contain NHC-CDI and acetate ligands terminally bound to linear Cu(I) centers. In contrast, the less encumbered ligand ICyCDIp-Tol, with p-tolyl substituents on the nitrogen donor atoms, affords a dicationic trigonal paddlewheel complex, [Cu2(μ-ICyCDIp-Tol)3]2+[OAc-]2 (2-OAc). The nuclear magnetic resonance (NMR) resonances of this compound are broad and indicate that in solution the acetate anion and the betaine ligands compete for binding the Cu atom. Replacing the external acetate with the less coordinating tetraphenylborate anion provides the corresponding derivative 2-BPh4 that, in contrast with 2-OAc, gives rise to sharp and well-defined NMR spectra. The short Cu-Cu distance in the binuclear dication [Cu2(μ-ICyCDIp-Tol)3]2+ observed in the X-ray structures of 2-BPh4 and 2-OAc, ca. 2.42 ?, points to a relatively strong "cuprophilic" interaction. Attempts to force the bridging coordination mode of IMeCDIDiPP displacing the acetate anion with BPh4- led to the isolation of the cationic mononuclear derivative [Cu(IMeCDIDiPP)2]+[BPh4]- (3b) that contains two terminally bound betaine ligands. Compound 3b readily decomposes upon being heated, cleanly affording the bis-carbene complex [Cu(IMe)2]+[BPh4-] (4) and releasing the corresponding carbodiimide (C(=N-DiPP)2).
METHOD FOR PRODUCING CARBODIIMIDES
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Paragraph 0053, (2020/10/31)
The invention relates to a novel method for preparing carbodiimides.
Synthesis, Structure, and Reactivity of Low-Spin Cobalt(II) Imido Complexes [(Me3P)3Co(NAr)]
Liu, Yang,Du, Jingzhen,Deng, Liang
, p. 8278 - 8286 (2017/07/22)
The reactions of [Co(PMe3)4] with the bulky organic azides, DippN3 and DmpN3 [Dipp, 2,6-diisopropylphenyl; Dmp, 2,6-di(2′,4′,6′-trimethylphenyl)phenyl], afforded the cobalt(II) terminal imido complexes [(Me3P)3Co(NAr)] (Ar = Dipp, 1; Dmp, 2). The cobalt imido complexes in their solid states show trigonal pyramidal coordination geometry and long Co-N(imido) separations (ca. 1.71 ?). Spectroscopic characterization and theoretical studies indicated their low-spin cobalt(II) nature. Reactivity studies on 1 revealed its nitrene-transfer reactions with PMe3 and CO, the imido/oxo and imido/sulfido exchange reactions with PhCHO and CS2, and the single-electron oxidation reaction by ferrocenium cation to form cobalt(III) imide.
Synthesis, characterisation and structural studies of amidinate and guanidinate alkaline earth–transition metal bonded complexes
Green, Ross,Walker, Alicia C.,Blake, Matthew P.,Mountford, Philip
, p. 64 - 75 (2016/08/23)
Reaction of magnesium amidinate complexes of the form [{MesC(NR)2}MgBr(OEt2)]2(R?=?iPr, Dipp, Mes) with the potassium salts of transition metal anions K[CpFe(CO)2] (K[Fp]) and K[Co(CO)3(PCy3)](THF)2gave the complexes {MesC(NR)2}MgFp(THF) and {MesC(NR)2}Mg{Co(CO)3(PCy3)}(THF). Single crystal X-ray diffraction studies of {MesC(NR)2}Mg{Co(CO)3(PCy3)}(THF) for R?=?iPr and Dipp confirm these to have Mg–Co bonds in the solid state. Reaction of the structurally similar magnesium guanidinate complex {Me2NC(NDipp)2}MgI(OEt2) with the aforementioned transition metal anions or K[Co(CO)3(PPh3)](THF) gave the series of complexes [{Me2NC(NDipp)2}MgFp]2, {Me2NC(NDipp)2}Mg{Co(CO)3(PCy3)}(OEt2) and {Me2NC(NDipp)2}Mg{Co(CO)3(PPh3)}(OEt2). Structural authentication by X-ray crystallography showed [{Me2NC(NDipp)2}MgFp]2to be a very rare example of a base-free alkaline earth–transition bonded complex, having two Mg–Fe bonds. IR and diffusion NMR spectroscopy was carried out to gain further insight into the solid state and solution phase structures.
