MRD CI study of the photodissociation of HO2 into OH(X2II) + O(3P, 1D)

A MRD CI procedure has been used to calculate several electronic states of the hydroperoxyl radical. The basis set is of double-zeta plus polarization quality augmented with s- and p-type bond and Rydberg functions. The vertical excitation energies of the lowest eight doublet and six quartet states are reported. Oscillator strengths for transitions form the ground to upper doublet states were calculated. A cut of the potential energy surfaces along the OOH fragmentation pathway is used to discuss the mechanisms of HO₂ photodissociation below 6.4 eV. Arguments are presented which indicate O(¹D) rather than O(³P) is the primary dissociation product, and so support the experimental findings rather than theory in the conflict raised earlier on this matter. Ostensibly the dissociation proceeds diabatically on the surface of the initially populated ²A″(1a″ → 2a″) state yielding OH(X²II) + O(¹D).     

Ab initio study of the Renner-Teller effect in 1Δg state of CH2

Results of a theoretical study of the Renner-Teller effect in the ¹Δ_g state of methylene are presented. Calculations are based on potential-energy surfaces for ¹A₁ and ¹B₁ electronic states obtained by the ab initio MRD CI method.     

Fluoride-mediated selective cross-coupling reactions of alkyl halides and trimethyl(perfluoroalkyl)silanes, Me3SiRf (Rf = CF3, C2F5) in the absence of any catalysts

A temperature range of −18 °C to room temperature was found to be effective for selective fluoride-mediated cross-coupling reactions of trimethyl(perfluoroalkyl)silanes, Me₃SiCF₃ and Me₃SiC₂F₅, and alkyl halides, RX (X = Br, I) in the absence of any catalyst.     

Characterization of buried interfaces by multiple internal reflection spectroscopy (MIRS)

Multiple internal reflection spectroscopy (MIRS) was applied to analyse atomic bonds at deep (500 m) interfaces of directly bonded Si/Si wafer pairs. It is shown that under the conditions used the polarized spectra contain information only about the interface layer a few nanometers thick. Examples are given of analysing the Si-H- and SiO-H vibration modes and bands of undissociated water in interfaces of bonded hydrophobic and hydrophilic wafer pairs, respectively, after annealing at temperatures between 200 and 1100 °C. Variations of the bonding behaviour (especially caused by alterations of the Si-H bonds) are discussed.Dedicated to Professor Dr. rer.nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday     

Theoretical study of the vertical electronic spectrum of O2: Mixing of valence and Rydberg states

All-valence-electron CM calculations are reported for a large number of electronic states of O₂ at the ground state equilibrium bond length. The configuration subspaces considered include all single and double excitations with respect to a series of the most important terms in the expansion of each state. The importance of the choice of such reference configurations as well as of the use of approximate natural orbitals in these calculations is discussed Mixing at Rydberg and valence states is observed in numerous cases and the significance of this phenomenon in the interpretation of the electrons spectrum of this system is considered.