Gesehen am 16.08.2024 ; Published: 10 January 2023
The synthesis and characterization of triazenido complexes of the group IV metals zirconium and hafnium is reported. The reaction of the group IV pentafulvene complexes Cp*(π–η5:σ–η1-pentafulvene)-zirconium(IV) and -hafnium(IV)chlorides with the sterically demanding 2,6-dimesitylphenyl azide results in the insertion of the γ-nitrogen atom of the ligand precursor into the polarized M–Cexo (Cexo: exocyclic carbon atom) bond of the pentafulvene ligand, forming a formal Cp,N,N tridentate ligand system. The molecular structures of the furnished complexes reveal the rare κ1N coordination of the γ-nitrogen atom to the zirconium or hafnium center along with a localized Nα–Nβ double bond. Unusually, in one case, the ligand system shows additional coordination of the α-nitrogen atom to the central metal atom and well-balanced N–N distances, thus, forming the chelating κ2N,N coordination mode of the triazenido ligand. The potential use of the formed complexes as precursors for cationic group IV cationic complexes was investigated by reaction with methyl lithium.
Organometallics Washington, DC : ACS Publ., 1982 42(2023), 12, Seite 1259-1266 Online-Ressource
Gesehen am 12.08.2024 ; FIrst published online: 11 January 2023
Addition of the parent allene H2C═C═CH2 to the bis(pentafulvene)titanium complexes Ti1a,b results in the formal nucleophilic attack of one of the exocyclic quaternary carbon atoms (Cq,exo) of one pentafulvene ligand at the central propa-1,2-diene carbon atom to form the titanium complexes Ti2a,b bearing both one intact pentafulvene ligand and a bidentate cyclopentadienyl-/allyl-based ligand, whose functionalities are spaced by a C1 linker. Investigations into the nature of the Ti–allyl interaction is established by multinuclear NMR spectroscopy, single crystal X-ray diffraction, and combined computational studies. A first glimpse of the reactivity of Ti2a,b is demonstrated showing that both the intact pentafulvene ligand and the allyl unit can be modified.
Organometallics Washington, DC : ACS Publ., 1982 42(2023), 11, Seite 1043-1047 Online-Ressource