Rearrangement of phosphinohydrazide ligand -NPh-N(PPh2)(2) in transition metal coordination sphere: Synthesis and characterization of nickel and cobalt spirocyclic complexes M(NPh-PPh2=N-PPh2)(2) and their properties

• Published in: Journal of organometallic chemistry Vol. 691; no. 5; pp. 879 - 889
• Main Authors: Sushev, VV, Kornev, AN, Min'ko, YA, Belina, NV, Kurskiy, YA, Kuznetsova, OV, Fukin, GK, Baranov, EV, Cherkasov, VK, Abakumov, GA
• Format: Journal Article
• Language: English
• Published: LAUSANNE Elsevier 15.02.2006
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Physical Sciences; Science & Technology; nickel; phosphazanes; STABILIZATION; X-ray diffraction; cobalt; phosphazane rearrangements; phosphinohydrazines; amidoimidophosphoranes; transition metal complexes; CHEMISTRY; phosphinoamides; PALLADIUM(II); POLYFUNCTIONAL MOLECULES; PHOSPHAZENE ANION
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/j.jorganchem.2005.10.030

The reaction of diphosphinohydrazine PhNH-N(PPh2)(2) (1) with cobalt(II) silylamide, Co[N(SiMe3)(2)](2), proceeds via formation of unstable phosphinohydrazide complex Co[NPh-N(PPh2)(2)](2) followed by rearrangement to a new chelating compound Co(NPhPPh,=N-PPh2)(2) (2). Disproportionation of nickel(I) silylamide, (Ph3P)(2)Ni-N(SiMe3)(2), in the presence of 1, yields Ni(0) and Ni(II) phosphinoamide complexes: Ni[(Ph2P)(2)N-NPhH](2) (3), Ni(NPh-PPh2=N-PPh2)(2) (4). X-ray analysis reveals tetrahedral environment of the cobalt atom in 2 and square-planar environment of the nickel atom in cis-4. In contrast to the crystalline patterns, the solutions of 2 in THF or toluene have EPR signal which is typical to square-planar low-spin d(7) cobalt complex. The reactions of 2 with dioxygen, elemental sulfur and diphenyldiazomethane led to the spirocyclic insertion products Co(NPh-PPh2=N-PPh2=X)(2) (X = O, S, NNCPh2) while the absorption of carbon monoxide is reversible. (c) 2005 Elsevier B.V. All rights reserved.