Transition-metal-carbene chemistry. Structure, thermodynamics, and reactivity of rhodium methylidene ion (RhCH2+) in the gas phase

Reactions of benzene with rhodium cluster cations: Competition between chemisorption and physisorption

“…Rate constants for the physisorption reaction of perdeuterated benzene with rhodium clusters Rh n ϩ , nϭ1,...,21 in comparison to physisorption reactions with benzene-h 6 . The benzene-d 6 data closely follow those from benzene-h 6 reactions except for nϭ9, 11,12 where perdeuteration enhances the physisorption probability slightly.…”

“…7͑b͔͒ in a fast flow reactor have been reported in addition to a considerable number of studies on the reactivity of monatomic Rh ϩ . [8][9][10][11][12][13][14][15] The high reactivity of rhodium towards hydrogen explains its effectiveness as a hydrogenation catalyst. 7,16,17 Unlike niobium, later transition elements like rhodium are much less reactive towards carbon.…”

Reaction of FeCH2++ D2: Probing the [FeCH4]+Potential Energy Surface

“…In previous work on the Fe + + CH 4 system, Schultz et al 9 formed Fe + using both surface ionization and drift cell techniques which allowed results for different electronic states of iron to be extracted. Previously, Jacobson and Freiser 5 found that FeCH 2 + was unreactive with H 2 at thermal energies even though formation of Fe + + CH 4 is exothermic by 1.18 ( 0.05 eV. However, the only products observed were FeH + and FeCH 3 + , formed in reactions 2 and 3, respectively.…”

Mechanisms of catalytic dehydrogenation of alkanes by rhodium clusters Rhn+ probed by isotope labelling

“…An experiment was designed to probe the possibility of a split C C bond by adding CD 4 to the cell already containing ethane. However, no H/D exchange with CD 4 was observed as had been found in the reaction of RhCD 2 + with CH 4 [8]. In principle this could have two different reasons; either the possible incapacity of rhodium clusters to activate the C H bond in methane (methane is not dehydrogenated by "naked" rhodium clusters, 2 < n < 20) or simply the absence of a methylene species, because the C C bond within Rh n ,C 2 ,H 4 + is intact.…”

“…Further insights are gained by directly comparing the behaviour of gaseous and supported atoms and clusters, as demonstrated for instance for rhodium in catalysing the trimerisation of acetylene [7]. Numerous experimental studies on rhodium cations [8][9][10][11][12][13][14] and rhodium clusters [15][16][17] as well as theoretical calculations [18][19][20] have aimed in understanding the principles for dehydrogenation of hydrocarbons, in particular alkanes. The metal clusters mimic essential features * Corresponding author.…”