Catalytic hydrogenolysis of alkyl halides by sulfido-bridged molybdenum clusters: A density functional study

Computational Insights into the Mechanisms of H2 Activation and H2/D2 Isotope Exchange by Dimolybdenum Tetrasulfide Complexes

“…This result is in line with the computed barrier of 43 kcal mol -1 for the same process with Cp 2 Mo 2 (μ-SH)(μ-S)(μ-S 2 CH 2 ), which was explained on the basis of the disruption of the Mo-S π bonding in the reactant. [10] In the present case, the activation strain model (ASM) analysis of TS1-a/3 clearly agrees with such a description, as it shows that almost 90 % of the activation barrier comes from the deformation of the dinuclear cluster (see Table 1). The oxidative addition of H 2 to one of the molybdenum centres (Pathway B) can also be discarded, as calculations show that both dihydrogen and dihydride reaction products do not represent stationary points on the PES.…”

“…amples of species in which sulfur and oxygen donor ligands behave as proton acceptors through mechanisms that imply the [2+2] addition of H 2 across the M-Q (Q = chalcogenide) bond (also known as σ-bond metathesis, [7] Scheme 1, c), [8][9][10] as well as cases in which H 2 is activated without the direct participation of the metal atom through the [3+2] addition to a cis-MQ 2 moiety of the complex (Scheme 1, d). [11] Scheme 1.…”

On the Synthesis and Chemical Behaviour of the Elusive Bis(hydrosulfido)‐Bridged Dinuclear Rhodium(I) Complexes [{Rh(μ‐SH)(CO)(PR3)}2]

“…The 1/[4] vs t representation ( Figure 5b) provided a linear fit that is representative of a second-order kinetic transformation with the slope of the line corresponding to the second-order rate constant k (Lmol -1 h -1 ). [23] The temperature influence on the reaction rate was investigated in the temperature range [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] o C in C 6 D 6 . The rate constant was determined at four different temperatures (Table 5) and the overall activation parameters were determined using the logarithmic form of the Eyring equation:…”

“…This species probably breaks down into the trinuclear hydrosulfido-sulfido [34] Finally, as far as the transformation of [Rh 3 (µ 3 -SH)(µ 3 -S)(CO) 3 (PPh 3 ) 3 ] into 5 is concerned, it is worth mentioning that the hydrogen migration from metal to sulfur, with a switch from hydride to proton character, respectively, has been proposed in the DFT study of the catalytic activity of sulfido-bridged molybdenum clusters in hydrogenolysis of alkyl halides. [35] …”

Transition metal sulfide clusters below the cluster–platelet transition: Theory and experiment

“…Mo m S n clusters exist in a large variety of compositions with many different characteristic structural elements. Hence several experimental and theoretical investigations have been carried out to assess the potential of Mo m S n clusters for large‐scale applications such as hydrogen storage 1, homogeneous 2, 3 and heterogeneous redox catalysis 4, 5, or as lubricant in the form of MoS 2 6, MoS 3 nanoparticles 7, and fullerene‐like MoS 2 and WS 2 nanoparticles 8. Both free and adsorbed small Mo m S n clusters exhibit either a three‐dimensional structure based on a Mo m framework or a platelet‐shaped geometry derived from the layered MoS 2 bulk structure 9, 10.…”