Theoretical study of the core binding energies of ozone and oxygen difluoride

Abstract

dimerization energy, 101 kcal/mol. This value may be overestimated by MNDO,B but aggregates of dilithioethane are certainly expected to be much more stable than the monomer. Triplet States of 1,2-DilithioethaneAll bonding orbitals in electron-deficient lithium compounds are not occupied. Thus triplet states are often readily accessible.1° Geometry optimization of the triplet state of the partly bridged structure 1 leads to the symmetrical bridged 2. Triplet 3' was found to be lowest in energy. The well-known1° overestimation of triplet relative to singlet stabilities at the Hartree-Fock level is partly corrected using second-order Mdler-Plesset theory. At UMP2/4-31G//4-31G, triplet 3 is 17 kcal/mol less stable than singlet 1. We thus believe 1,2-dilithioethane to be a ground-state singlet. The MNDO results" agree with this conclusion. Transition Metal AnaloguesThe vast majority of elements in the periodic table are metals. Lithium, the first such element, can be expected to exhibit structural features which should be common to other metals. A remarkable analogy is found between the zirconio-ethylene complex with ZrCC angles of 75.9O (X-ray), and 1, with LiCC angles of 73.3' (4-31G).(30) P. Hofmann and P. Stauffert, submitted for publication. See Abstract: The core binding energies of O3 and OFz have been calculated as the difference between the total Hartree-Fock energies of the hole states (core electron missing) and the neutral ground states. The results are compared with experimental values. The agreement is very good except for the central oxygen of ozone. The trends in binding energies, as they reflect the bonding in the two molecules, are discussed in terms of the u and ?r contributions.Abstracf The absolute configuration of (R)-[2-2Hl]cyclopentanone is established through synthesis using as the key step chiral epoxidation with the Sharpless reagent. Its circular dichroism (CD) spectrum is unusual in that it exhibits a bisignate Cotton effect being negative at 310 and positive at 275 nm. From the interpretation on the variable-temperature CD measurements, the unexpected conclusion is reached that the twist conformation with the deuterium in the quasi-equatorial position is energetically preferred by ca. 10 f 2 cal/mol. Evidently, even at room temperature, the contribution toward the spectrum resulting from the conformational isotope effect is of the same or larger amplitude but opposite sign compared to the difference between the partial octant contributions of an a-quasi-equatorial and a-quasi-axial deuterium substituent.

In situ dry cleaning of Si wafer using OF2/NH3 remote plasma with low global warming potential

“…However, NF 3 is a greenhouse gas with a high global warming potential (GWP) of 17 200 (17 200 times higher than that of CO 2 ) and a new alternative gas mixture is needed to replace NF 3 [18,19]. Oxygen difluoride (OF 2 ) having the GWP (<1) is one of the most potential gases to replace NF 3 and is the gas with a low-binding energy of the material for high-gas decomposition efficiency [20][21][22].…”

Calculations of core‐electron binding energies by transition operator method followed by Rayleigh–Schröudinger perturbation theory

“…Considerable effort has therefore been spent on treating this orbital reorganization. The traditional approach is the well-known ASCF method [27][28][29][30][31][32][33][34][35][36][37][38][39][40] which requires separate SCF calculations for both the parent molecule and the core-hole cation. An alternative procedure is the transition-state method developed by Slater [41][42][43][44] based on an energy functional with continuously varying occupation numbers.…”