116323-75-2Relevant academic research and scientific papers
Transformation of a terminal phenylethenylidene ligand to a μ-η1,η4-phenylethenyl ligand or a μ-η1,η2-phenylethenyl ligand: Structural characterization of a plausible intermediate species of a fluxional process
Lukehart, Charles M.,True, William R.
, p. 2387 - 2393 (2008/10/08)
Addition of the Pt-H bond of [trans-Pt(H)(PEt3)2(acetone)]+ to a tungsten terminal phenylethenylidene ligand, W=C=C(Ph)(H), occurs with the unexpected regiochemistry of H addition to the α-carbon atom and Pt addition to the tungsten atom to form a heterodinuclear complex containing a bridging styryl ligand. Spectroscopic data of the product in both solution phase and the solid state are consistent with a structure having a μ-η1,η4-styryl ligand. Variable-temperature 1H NMR data confirm a dynamic process having a ΔG?(198 K) of ca. 9.4 kcal/mol for an exchange between equivalent μ-η1,η4-styryl structures in analogy to the fluxional behavior of η3-benzyl ligands. However, the X-ray structure of the product containing CHCl3 of crystallization in the lattice reveals a molecular structure possessing a μ-η1,η2-styryl ligand: {PtW[μ-η1,η2-C(H)=C(H)(Ph)](PEt 3)2(Ph2PCH2CH2PPh 2)(CO)3}BF4-CHCl3; triclinic; P1; Z = 2; a = 15.689 (3) A?, b = 16.192 (4) A?, c = 11.799 (2) A?; α = 93.69 (2)°, β = 95.66 (2)°, γ = 89.98 (2)°. This structure is analogous to a η1-benzyl structure which is a plausible intermediate for the exchange process of the μ-η1,η4-styryl ligand.
