om400305z_si_002.cif (208.46 kB)
Toward the Synthesis of Indenyl Molybdenum Compound [(η3‑Ind)(η5‑Cp)Mo(CO)2]: Modified Compounds and Structure of a Previously Unrecognized Intermediate
dataset
posted on 2016-02-19, 05:20 authored by Jan Honzíček, Jaromír Vinklárek, Milan Erben, Jakub Lodinský, Libor Dostál, Zdeňka PadělkováThe mechanism of synthesis of [(η3-Ind′)(η5-Cp)Mo(CO)2] was studied on methyl-substituted
derivatives (Ind′ = 2-MeC9H6; 4,7-Me2C9H5). It was observed that the initial
step involving reaction with HCl gives dimeric chloride species [{(η5-Ind′)Mo(CO)2(μ-Cl)}2]. This outcome differs from the structure suggested in the literature.
Furthermore, it was demonstrated by various examples that compounds
of the formula [{(η5-Ind′)Mo(CO)2(μ-Cl)}2] are convenient starting materials
giving [(η3-Ind′)(η5-Cp′)Mo(CO)2] through the reaction with appropriate cyclopentadienides.
The variability of this method was demonstrated on several examples
including weakly donating Cp ligands bearing strong electron-withdrawing
functional groups [C5H4COOMe, (1,2-MeOCO)2C5H3, and 1,2-(tBuNHCO)2C5H3] as well as Cp
ligands bearing a pendant amine arm (C5H4CH2CH2NMe2). Similar η3-indenyl complexes are formed when using other univalent six-electron
ligands such as carbaborane (9-Me2S-7,8-nido-C2B9H10) or scorpionate (Tp, Tp*).
The attempts to synthesize [(η3-Ind)(η5-Cp)Mo(CO)2] from [(η3-C3H5)(η5-Cp)Mo(CO)2] have
failed because the initial reaction with HCl does not give the expected
[{(η5-Cp)Mo(CO)2(μ-Cl)}2] but trivial [(η5-Cp)Mo(CO)3Cl].