Formation of a hydrogenation catalyst in the cobalt acetylacetonate-triethylaluminum system

Unintuitive Inverse Dependence of the Apparent Turnover Frequency on Precatalyst Concentration: A Quantitative Explanation in the Case of Ziegler-Type Nanoparticle Catalysts Made from [(1,5-COD)Ir(μ-O2C8H15)]2 and AlEt3

“…An inverse relationship has been observed in the Co­(acac) 2 plus AlEt 3 Ziegler-type hydrogenation catalyst system studied by Shmidt and co-workers (Figure ). In their study, Shmidt and co-workers interpreted the inverse relationship as evidence for a heterogeneous catalyst, arguing that if the system was a homogeneous catalyst, then it would have shown an invariant TOF as a function of concentration.…”

“…The closest analogue to our Ir/AlEt 3 system in the extant Ziegler nanocluster literature comes from the published, important work of Shmidt and co-workers . Their Co­(acac) 2 /AlEt 3 -based catalyst system also employs a metal in the Co, Rh, Ir group and utilizes the same AlEt 3 stabilizer.…”

“…Clearly, the AlEt 3 dissociative scheme uncovered herein and its associated eq 1 provide an excellent fit. That said, a more detailed interpretation of what this empirical fit means physically and mechanistically must await the following information, which is unclear from the published paper: what precise Al/Co ratio was used in this study; is that ratio changing as the [Co] changes; and which of the two precatalysts (differing in their water content) was used, Co(acac) 2 · n H 2 O, n = ∼2 or the n = 0 complex …”

“…Fitting of Nindakova et al’s 1-hexene hydrogenation data, for their Co(acac) 2 /AlEt 3 -based catalyst in heptane, to the AlEt 3 dissociative mechanism and its associate eq 1. The resulting constants are k cat2 = 1217(153), K app = 1.05(32), and the stabilizer dissociation number is x = 1.09(12) . Clearly, the AlEt 3 dissociative scheme uncovered herein and its associated eq 1 provide an excellent fit.…”

Highly effective organometallic‐mediated radical polymerization of vinyl acetate using alumina‐supported Co(acac)2 catalyst: A case study of adsorption and polymerization

“…Other peaks in the two spectra are not highly different from each other and are mostly belong to the alumina support. For example, the bands at ∼822 and ∼547 cm −1 correspond to AlOAl bending mode and AlO stretching mode, respectively …”