Tungsten and Molybdenum Alkyl or Aryl Complexes That Contain the [(C₆F₅NCH₂CH₂)₃N]^3- Ligand

[N₃N_F]W(OC₆F₅) and [N₃N_F]W(O-3,5-Me₂C₆H₃) ([N₃N_F]^3- = [(C₆F₅NCH₂CH₂)₃N]^3-) can be prepared readily from [N₃N_F]WCl in good yields. An X-ray study of the latter revealed an approximately trigonal structure with the phenoxide in the trigonal pocket. Alkylation of [N₃N_F]WCl with LiCH₂R (R = Me, n-Pr, SiMe₃, CMe₃) reagents in toluene at room temperature led to the evolution of molecular hydrogen and formation of the corresponding tungsten(VI) alkylidyne complexes, [N₃N_F]W⋮CR (R = Me, n-Pr, SiMe₃, CMe₃). The intermediate [N₃N_F]W(CH₂SiMe₃) decomposed in a first-order manner to give [N₃N_F]W⋮CSiMe₃ (ΔH^⧧ = 20.3 ± 0.2 kcal/mol, ΔS^⧧ = −7 ± 1 eu). An X-ray study of [N₃N_F]W⋮CSiMe₃ showed it to have the expected, relatively undistorted, structure in which the W−C triple bond distance is 1.768(6) Å. Although attempts to prepare [N₃N_F]WCH₃ were not successful, [N₃N_F]W⋮CH could be prepared by reacting [N₃N_F]WCl with cyclopropyllithium in toluene. [N₃N_F]MoCl reacts with LiCH₂SiMe₃ or LiCH₂CMe₃ in toluene to yield [N₃N_F]Mo(CH₂CMe₃) or [N₃N_F]Mo(CH₂SiMe₃), respectively. Thermolysis of [N₃N_F]Mo(CH₂CMe₃) produced [N₃N_F]Mo⋮CCMe₃ in a first-order reaction at 121 °C (k = 7.9(5) × 10^-5 s^-1). Several labeling experiments are consistent with the proposal that β-elimination competes with α-elimination and loss of molecular hydrogen in the [N₃N_F]^3- system. [N₃N_F]WI reacts with aryllithium reagents (Ar = Ph, 3,5-Me₂C₆H₃) to yield [N₃N_F]WPh and [N₃N_F]W(3,5-Me₂C₆H₃). The aryl complexes react with hydrogen (3 atm) in toluene at 40 °C to yield diamagnetic [N₃N]WH₃ and are cleanly oxidized by pyridine N-oxide. An X-ray study of [N₃N_F]W(O)(3,5-Me₂C₆H₃) revealed it to have a pseudo-octahedral structure. [N₃N_F]W(3,5-Me₂C₆H₃) reacts with trimethylsilyl azide to give [N₃N_F]W(NSiMe₃)(3,5-Me₂C₆H₃).