RESUMO
A well-defined, isolated, single-site organovanadium(iii) catalyst on SiO2 [(SiO2)V(Mes)(THF)] was synthesized via surface organometallic chemistry, and fully characterized using a combination of analytical and spectroscopic techniques (EA, ICP, 1H NMR, TGA-MS, EPR, XPS, DR-UV/Vis, UV-Raman, DRIFTS, XAS). The catalyst exhibits unprecedented reactivity in liquid- and gas-phase alkene/alkyne hydrogenation. Kinetic poisoning experiments revealed that 100% of the V sites are active for hydrogenation.
RESUMO
The synthesis of molybdenum oxo-amidinate complexes MoO2(R2AMD)2 [AMD = N,N'-di-R-acetamidinate; R = Cy (2; cyclohexyl) and iPr (3)], and their characterization by 1H, 13C NMR, X-ray diffraction, and thermogravimetric analysis is reported. Quartz-crystal microbalance and X-ray photoelectron spectroscopic studies confirm that 3 is an improved ALD precursor versus the R = t-butyl derivative for MoO3 film growth. Complex 3 is accessible in higher yields (80%+), is easier to handle without mass loss, and in conjunction with O3 as the second ALD reagent, yields nitride-free MoO3 films.
