Pentafulvenkomplexe des Titans — Synthese, Struktur und Fluktuierendes Verhalten von Cp′Ti{η6-C5H4=C(p-Tol)2}Cl (Cp′ = Cp*, Cp)

Cationic Group 4 Complexes (M = Ti, Zr, Hf): Modifications and Limitations in the Design of Tridentate Cp,O,P‐Ligand Frameworks Built Directly in the Coordination Sphere of the Metal

“…Previously, we have established an efficient synthetic protocol for the synthesis of cationic complexes of all group 4 metals with tridentate Cp , D , P ‐ligand frameworks (D = O, N) by reacting mixed cyclopentadienyl/monopentafulvene precursor complexes with bifunctional ligand precursors (Scheme , B ) , . Those bidentate ligand precursors feature one functional group (FG), which is able to undergo an insertion reaction into the polarized bond between the metal and the exocyclic carbon atom (C exo ) of the π ‐η 5 : σ ‐η 1 bonded monopentafulvene ligand (carbonyl or nitrile functional group) and one phosphine functional group to enable interactions between the Lewis acidic metal center and the Lewis basic phosphine moiety in the cationic complexes.…”

Bis(η5:η1‐pentafulvene)niobium(V) Complexes: Efficient Synthons for Niobium Carbene and Imido Derivatives

“…The molecular structure of 1 shows a significant reduction of the pentafulvene ligands, as evident by the angles ( θ =28.5°, 32.2°) of the exocyclic C−C bond out of the five‐membered ring plane, and by the elongation of the exocyclic bonds C ipso −C exo (1.423(4) Å, 1.431(4) Å) compared to a value of 1.359(2) Å in the isolated ligand . Furthermore, characteristic of the dianionic π‐η 5 :σ‐η 1 structure is the ring slippage (Δ=0.175 Å, 0.202 Å) toward the C ipso atom of the five‐membered ring.…”

Theoretical studies on titanium pentafulvene complexes

“…All of the complexes 1-6 show a distinct color, and their UV-Vis spectra have been recorded [46,47,56]. It therefore seems straightforward to theoretically investigate the excitation behavior which allows the correct reproduction of excitation energies and gives information on the nature of the excitation.…”

“…In such a way, the monocyclopentadienyltitaniumpentafulvene chlorides (2)(3)(4)(5) [46][47][48] as well as derivatives there of (e.g., 1) becomes available in acceptable yields (Table 1, Fig. 1).…”

“…Experimental studies with titanium complexes 1-6, including UV-Vis and NMR investigations as well as crystallographic data, indicate that these complexes exist in a coordination between the dianionic (E) and an olefinic form (D) [46][47][48]56]. We therefore set out to theoretically analyze this situation using geometry optimizations, excited states calculations and population analyses.…”