Insertion of Acetonitrile into the Zr−P Bond of [Cp°₂ZrCl(PHCy)] (Cy = Cyclohexyl, Cp° = η⁵-C₅EtMe₄) Followed by PHCy Elimination To Give [Cp°₂(Cl)Zr(μ-NCMe−CMeN)Zr(Cl)Cp°₂]

Abstract

[Cp°2ZrCl(PHCy)] (Cy = cyclohexyl, Cp° = η5-C5EtMe4) undergoes insertion of MeCN into the Zr−P bond, yielding [Cp°2ZrCl{NC(Me)(PHCy)}] (1). Isomers with a Z (1a) or E (1b) configuration at the C−N double bond are obtained in a ratio of 13:1. At room temperature, 1 slowly decomposes in solution with elimination of a PHCy fragment and formation of [Cp°2(Cl)Zr(μ-NCMe−CMeN)Zr(Cl)Cp°2] (2). Two isomers are obtained with a trans (2a) or cis (2b) arrangement around the C−N double bonds of the bridging butane-2,3-diimino(2-)-N,N‘ ligand. 1a, 2a, and 2b were isolated and characterized by IR, MS, and NMR spectroscopy (1H, 31P, 13C), and crystal structure determinations were carried out on 1a and 2a. In the solid state, the short Zr−N bonds and the almost linear Zr−N−C angles of 1a and 2a indicate the presence of Zr−N double bonds.

Diastereoselective Insertion of Isocyanide into the Alkyl−Metal Bond of Methylbenz[e]indenyl ansa‐Zirconocene Complexes

“…[21,36] However the zirconium-nitrogen bond length [ZrϪN 2.2872(16) Å ] is slightly longer than those found in related zirconium iminoacyl compounds in the range 2.148Ϫ2.250Å . [37,38] The double bond character of the iminoacyl C(10)ϪN bond is confirmed by the 1.281(3) Å distance, which is longer than usual for related zirconium iminoacyl compounds and close to that known for organic CϭN bonds [1.28Å ]. [35] All of these elongated bonds are consistent with the steric hindrance due to the bulky MBI ring and the benzyl and 2,6-xylyl substituents.…”

Investigation in the coupling of zirconocene complexes and trimethylsilyl(diphenylphosphino)acetylene. P–C bond cleavage chemistry from protonolysis reactions

“…b-Elimination reaction with halogen as leaving group in zirconacyclopentadiene complexes to afford the corresponding alkynyl zirconation product was lately observed by Takahashi and coll [15]. Moreover P-C bond cleavage in b-phosphorus zirconocene complexes was already exemplified [16]. We also proposed earlier that isolation of the homoallylic phosphine compound PhP(H)(CH 2 ) 2 CH@CH 2 after addition of HCl to the starting b-zirconocene phospholane complex may arise from the transient formation of the corresponding phosphonium zirconocene complex followed by P-C bond cleavage (Eq.…”

Enhancing the Value of Free Metals in the Synthesis of Lanthanoid Formamidinates: Is a Co‐oxidant Needed?

“…Currently there appear to be no structurally characterised complexes of the exact (Z)-but-2-ene-2,3-diamide ligand for any metal system, [13a] making the structure unique. However the oxidised neutral form of the ligand (HN=C(Me)ÀC(Me)=NH, glyimine) has recently been trapped in an Fe II complex, [26] whilst the derived anionic ligand À N= C(Me)ÀC(Me)=N À is quite well knowni nabridgingr ole in an E configuration, [27] In addition, the free E dianion has been characterised as the counter ion foraruthenium complex. [28] Attempts at aD Mm etal synthesis between activated Yb metal and DippFormH in CH 3 CN failed to produce [Yb(Dipp-Form) 2 (CH 3 CN) 3 ]( Yb5 a).…”