Dynamics of CO elimination from reactions of yttrium atoms with formaldehyde, acetaldehyde, and acetone

Abstract

Reactions of neutral, ground-state yttrium atoms with formaldehyde, acetaldehyde, and acetone (YϩRRЈCO, where R,RЈϭH,CH 3) were studied in crossed molecular beams. At collision energies greater than 24 kcal/mol, four product channels were observed corresponding to elimination of CO, H 2 , H, and nonreactive scattering. For the dominant CO elimination channel, a large fraction ͑34%-41%͒ of the available energy appeared as kinetic energy of the products. RRKM modeling indicated this was a result of two factors: a large potential energy barrier for RЈ migration leading to (R)(RЈ)YCO and dissociation of this complex prior to complete energy randomization. The CM angular distributions were all forward-backward symmetric, indicating the existence of at least one long-lived reaction intermediate. The angular distributions ranged from being quite forwardbackward peaking for the YϩH 2 CO reaction to isotropic for Yϩ͑CH 3 ͒ 2 CO. A simple equation is derived based on statistical complex theory that relates the shape of the CM angular distributions to the structure of the dissociating complex.

Theoretical Investigation of the Decarbonylation of Acetaldehyde by Fe+ and Cr+

“…The hydride-containing compound is calculated to be 3. for aC1FeC2, aC2FeH1, and aH1FeC1, respectively), which is strictly analogous to that of the precursor of the reaction Y + CH 3 CHO!CH 3 YH + CO, studied in crossed molecular beam experiments by Schroden et al [40] This structural feature can be understood by the results of NBO analysis. On the basis of our calculations, in 6 3b' 4s Fe þ and 1s H1 orbitals form a s FeH aorbital, while the linkage of the other two groups (CO and CH 3 ) with Fe + is strengthened by the strong a-electron donations from the 2s2p z hybridized orbital of C1 and 2p x 2p z hybridized orbital of C2 to s* FeH (DE: 17.9 and 30.5 kcal mol À1 ), respectively (where the C s symmetry plane is defined by the xz coordinates with the z axis polarized along the CO).…”

Collision dynamics of proton with formaldehyde: Fragmentation and ionization

“…30 Second, the proton as a single ion-projectile is favored because of its missing electronic structure and capability of capturing electrons as well as its abundance in the solar wind and in the ISM. Third, so far, a great deal of work about formaldehyde has concentrated on unimolecular photodissociation, [31][32][33][34][35][36][37][38] collision-induced ionization and dissociation by electrons, 28, 39-43 atoms, [44][45][46][47][48][49][50] and ions. [51][52][53] Unfortunately, little is known about the physical process of proton impact on formaldehyde, although Jalbout 30 advanced the study of a single formaldehyde reacting with a single proton source (H + 3 , H 3 O + ).…”

Theoretical survey of the reaction between osmium and acetaldehyde

“…To better understand the fundamental aspects of this reaction, several studies have been reported on the investigation of the relevant mechanism [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. As one of the sim ple carbonyl containing organic molecules, acetalde hyde is used in many practical application fields such as organic synthesis, catalysis, etc.…”

“…Their results show that for Co + , Fe + , and Cr + , decarbonylation proceeds through C-C activation rather than aldehyde C-H activation, whereas both C-C and aldehyde C-H activation may result in the decarbonylation of CH 3 CHO by Ni + cation. Compared with the first row cation, heavier metal atoms and cations have received less attention, and only a few theoretical and experi mental studies have been reported [12][13][14]. Bayse et al [14] have investigated the reaction between yttrium atom and acetaldehyde in detail.…”