Activation of CH4, C2H6, and C3H8 by gas-phase Nb+ and the thermochemistry of Nb–ligand complexes

The most reactive third-row transition metal: Guided ion beam and theoretical studies of the activation of methane by Ir+

“…Ir + exhibits greater reactivity toward methane than any ions of the first-row and second-row metals [4,9,17,18]. To characterize these differences, we explicitly compare the present results with comparable studies of the kinetic energy dependence of the reaction of CH 4 with corresponding first-row and secondrow ions, Co + and Rh + [11,14].…”

“…This process is observed because the simple bond cleavage is kinetically more favorable at high energies than the more complex dehydrogenation process. Comparable observations have been made for second-row [11,16,17,68,69] and third-row (W + , Re + and Pt + ) metal systems [19][20][21].…”

“…Formation of IrD 2 + has the highest threshold of all processes observed, which is consistent with formation of the high-energy CD 2 neutral. The formation of MD 2 + product ions is unusual and has not been detected for reaction of methane with first-row [8][9][10][12][13][14][15]18], second-row [7,11,[16][17][18], and several thirdrow (La + , W + , Re + , Lu + ) transition metal ions [18,20,21]. However, this product has been observed in reactions of methane with Pt + [19].…”

“…Such ion beam studies also provide insight into the electronic requirements for the activation of methane by transition metal ions and periodic trends in this reactivity. We have applied this methodology to all the first-row and second-row transition metals except Tc [3,[7][8][9][10][11][12][13][14][15][16][17][18] and more recently to several of the third-row metals as well [18][19][20][21]. A significant advantage of these comprehensive studies is the comparison of bond energies and reactivities of all transition-metal complexes, thereby establishing periodic trends.…”

Theoretical investigation of the mechanism of tritiated methane dehydrogenation reaction using nickel-based catalysts

“…As a classic transition metal, nickel atoms or ions in the gas phase can react with methane as the active species. By simplifying the reaction, we were able to understand the process of selective breaking of aliphatic C H bonds [7][8][9][10][11][12]. Thus, the methane dehydrogenation reaction is of great interest in both the experimental field and theoretical calculations.…”