Intercalation of (eta(5)-Pentamethylcyclopentadienyl)trioxomolybdenum(VI) in a Layered Double Hydroxide

authors	Gomes, AC; Neves, P; Gago, S; Valente, AA; Goncalves, IS; Pillinger, M
nationality	International
journal	EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
author keywords	Molybdenum; Half-sandwich complexes; Oxido ligands; Cyclopentadienyl ligands; Layered compounds
keywords	OLEFIN EPOXIDATION; MOLYBDENUM; FERROCENE; COMPLEX
abstract	A Zn,Al layered double hydroxide (LDH) with [CpMoO3](-) (Cp = eta(5)-C5Me5) anions in the interlayer has been prepared by a direct coprecipitation method. The intercalated LDH and the mixed metal oxide (MMO) obtained after its calcination were characterized by elemental and thermogravimetric analyses, powder X-ray diffraction (PXRD), FT-IR and FT-Raman spectroscopy, C-13 and Al-27 MAS NMR, and scanning electron microscopy. The observed basal spacing of 17.1 angstrom for the LDH Zn,Al-CpMoO3 (corresponding to a gallery height of 12.3 angstrom) suggests that the guest anions self-assemble into dimers via offset face-to-face Cpcenter dot center dot center dot Cp* interactions, which facilitates hydrogen-bonding interactions between the oxido ligands of the complexes and the layer hydroxyl groups, while positioning the hydrophobic aromatic rings towards the center of the galleries. Calcination of Zn,Al-Cp*MoO3 at 550 degrees C under air gave an MMO comprising well-dispersed ZnO, alpha-ZnMoO4 and ZnAl2O4 (spinel) oxides in a molar of ca. 1.4:1.6:1. The MMO exhibited catalytic activity for the epoxidation of cis-cyclooctene with tert-butylhydroperoxide (TBHP) as terminal oxidant, with quantitative yield of the epoxide being achieved within 24 h at 85 degrees C.
publisher	WILEY-V C H VERLAG GMBH
issn	1434-1948
isbn	1099-0682
year published	2020
volume	2020
issue	25
beginning page	2408
ending page	2416
digital object identifier (doi)	10.1002/ejic.202000127
web of science category	Chemistry, Inorganic & Nuclear
subject category	Chemistry
unique article identifier	WOS:000533565800001