Dynamics of Y+H2CO reactions

Abstract

The reactions of ground state yttrium atoms (Y) with formaldehyde (H2CO) have been studied in crossed molecular beams as a function of collision energy (Ecoll). The potential energy barrier for C–H insertion is found to lie below 12 kcal/mol. It is proposed that the reaction is initiated by C–H insertion, producing HYCHO followed by H atom migration forming H2YCO. Although Y–CO bond fission leading to YH2+CO is dominant, a secondary minor channel also leads to the production of YCO+H2. Formation of YCHO+H is not observed at 16 kcal/mol, but is clearly seen at 31 kcal/mol, indicating that D0(Y–CHO) lies between 58 and 73 kcal/mol.

Rotational Analysis of the Ã2A1–X̃2A1 Band System of Yttrium Dicarbide, YC2

“…[12] by Eq. [11]. In principle this should allow the orbital corrections to the rotational constants, and therefore the electronic contribution to the inertial defect, to be obtained; in practice, though, the spin-orbit constants ζ α are not known well enough.…”

“…As can be seen from Eq. [11], the ratio ε aa /ε bb in the states of YC 2 should be equal to A/B. It is not possible to separate ε bb from ε cc for the ground state of YC 2 because the absence of K = 1 levels has resulted in their being almost totally correlated in a least squares sense.…”

“…The spin-orbit operator for a nonlinear molecule has the form [10] where the ζ α parameters are spin-orbit coupling constants, not to be confused with the Coriolis ζ constants. Application of second order perturbation theory to the matrix elements of the orbital angular momentum operators that are off-diagonal in electronic state then gives the relations [11] and…”

“…[11] and [12] the indices α and β run over the Cartesian coordinates x, y, and z; B αα is a rotational constant; state 0 is the electronic state of interest; and the electronic states n are all the others. The relation [13] is obtained on dividing Eq.…”

Reaction Dynamics of Carbon‐Centered Radicals in Extreme Environments Studied by the Crossed Molecular Beam Technique

“…86 These dynamics calculations are needed to turn the ab initio results into quantities that can be compared with experiments. Although interest in these light elementary reactions still continues, with the development of powerful theoretical models, attention is turning to more complex systems of significant practical interest such as in catalysis, [87][88][89] atmospheric chemistry, 90-92 interstellar [93][94][95] and planetary chemistry, 96-100 organometallic chemistry, 101-103 and combustion processes. [104][105][106][107][108] Due to the experimental difficulties in generating two unstable reactants simultaneously, only a very few atom-radical reactions have been conducted so far under single collision conditions.…”