Mössbauer and Infrared Studies of Reactions of Laser-Evaporated Iron Atoms with Methane

Abstract

The reaction of laser-evaporated iron atoms with methane gas was studied using a matrix-isolation technique, and the reaction products were observed by Mössbauer and infrared spectroscopy. The reaction produced CH3FeH in a CH4/Ar mixture, whereas Fe2H2(CH3)4 was also obtained in addition in a pure CH4 matrix. Molecular orbital calculations were performed in order to confirm the assignments.

Methane activation on Fe4 cluster: A density functional theory study

“…Among TMs, iron, the heaviest element with a significant cosmic abundance, is a desirable catalyst for activating the C-H bond in methane because it can decrease significantly the activation energy of C-H bond [2,3]. Recent research shows that iron can reduce the C-H bond activation energy to about [8][9][10][11][12][13][14][15][16][17][18][19][20] kcal/mol, depending on the Ni/Fe mixture [3]. Although small iron clusters are crucial in the catalytic reaction of activation of the C-H bond, there are a few studies on methane activation by iron alone, and most of these have focused on bulk iron or iron cations [4][5][6][7][8][9][10].…”

“…Although small iron clusters are crucial in the catalytic reaction of activation of the C-H bond, there are a few studies on methane activation by iron alone, and most of these have focused on bulk iron or iron cations [4][5][6][7][8][9][10]. With regards neutral Fe clusters, Yamamoto's group used Mössbauer spectroscopy to monitor the reaction between Fe 2 and CH 4 [11]. Castro studied the interaction of methane with Fe 4 clusters and our group has investigated methane activation on Fe monomer and dimer by using density functional theory method [12,13] The study of methane activation by neutral iron clusters which, beside its own importance, such as iron is one of the most economic affordable catalysts for methane activation reaction, may act as useful models for homogenous and heterogeneous catalysis.…”

Low-temperature reactions in the chemistry of nanosystems

“…and a hydrogen atom. The reaction in a methane matrix results in products of the interaction between primary radicals CH 92,93 Co-condensation of transition metal atoms with aromatic hydrocarbons at 77 ± 80 K often results in bisarene complexes of (formally) zero-valent metals. 94 For instance, co-condensation of lanthanide atoms and 1,3,5-tris-tert-butylbenzene produces thermally stable `sandwich' complexes of Nd, Tb, Dy, Ho, Er and Lu, as well as thermally unstable complexes of La, Pr, Sm, Eu, Tm and Yb.…”

14 Iron, cobalt and nickel

“…88 Laser-evaporated Fe atoms react with methane gas, among products isolated in matrices CH 3 FeH was identified in a CH 4 -Ar mixture with (CH 3 ) 4 Fe 2 H 2 additionally formed in a pure CH 4 matrix. 89 Reaction of [Ni(cod)(dtbpe)] with N 2 CPh 2 results in the formation of the diazoalkane complex [Ni(dtbpe)(N 2 CPh 2 )]; in solution in the presence of a catalytic amount of samarium triflate, nitrogen is extruded on heating forming a three coordinate carbene complex [Ni(dtbpe)(=CPh 2 )]. This undergoes insertion and addition reactions with small molecules such as CO, CO 2 and SO 2 .…”