Instability of stable negative ions in the Xα method or other local density functional schemes

Stable negative ions such as O^? and F^? are calculated to be unstable if exchange—correlation potentials of the Xα type are used, whereas the Hartree—Fock method correctly predicts their stability. The reason for this difference in stability is the difference in the one-electron energies between the two schemes.     

Zum Satz von Osgood und Hartogs für analytische Moduln. I

Ohne ZusammenfassungMeinem verehrten Lehrer Prof. H. Behnke zum 70. Geburtstag gewidmetDie vorliegende Schrift ist im wesentlichen der erste Teil meiner Habilitationsschrift, die ich während eines Aufenthaltes am Institute for Advanced Study überarbeitet und leicht verändert habe.     

Molecular and Crystal Structures of Some Fluorocymantrenes

The crystal and molecular structures of the fluorocymantrenes [(C₅H₄F)Mn(CO)₃] and [(C₅H_5?nF_n)Mn (CO)₂(PPh₃)] (n?=?1–3) have been studied. The influence of the phosphine for carbonyl substitution on the bond parameters is larger than the influence of the increasing fluorine content. In most cases the Mn?→?P vector is in a transoid position relative to the fluorine substituents, and therefore the conformational parameters of the PPh₃ propeller are in these cases very similar. The crystal structures show many intermolecular C–H?O hydrogen bonds and only very few C–H?F hydrogen bonds.

Graphic Abstract

The influence of the phosphine for carbonyl substitution on the bond parameters of the fluorocymantrenes [(C₅H₄F)Mn(CO)₃] and [(C₅H_5?nF_n)Mn (CO)₂(PPh₃)] (n?=?1–3) is larger than the influence of the increasing fluorine content.

     

Quantification of chlorinated naphthalenes with GC-MS using the molar response of electron impact ionization

Summary The concept of the molar response (MR) in HRGC/EI-MS has been checked for naphthalene and three chlorinated naphthalenes: 1-chloronaphthalene, 1,2,3,4-tetrachloronaphthalene and octachloronaphthalene. The molar response factors increase with increasing degree of chlorination. When the ion yield is normalized for the ionization cross section Q of the molecule, a constant value of injected molar mass to signal intensity is obtained for naphthalene up to octachloronaphthalene. It allows to quantify all chlorinated naphthalene congeners on the basis of one or two reference compounds. This has been done for the Cl_xN (x=1–8) in a technical mixture of polychlorinated naphthalenes (Halowax 1014) and in a MWI fly ash sample. The latter one had a concentration of 520 ng/g dry weight for the Cl_xN (x=1–8).Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthday     

Self-Similar Lattice Tilings

We study the general question of the existence of self-similar lattice tilings of Euclidean space. A necessary and sufficient geometric condition on the growth of the boundary of approximate tiles is reduced to a problem in Fourier analysis that is shown to have an elegant simple solution in dimension one. In dimension two we further prove the existence of connected self-similar lattice tilings for parabolic and elliptic dilations. These results apply to produce Haar wavelet bases and certain canonical number systems.     

Diastereospecific synthesis of fungicidal threo- and erythro- α-hydroxy aminals

Sequential reactions of 2-chloro- or 2-bromo-3-tert-butyloxirane with p-chlorophenolate and then with sodium triazolate lead in two stereocontrolled steps to threo-Triadimenol; by inverse addition of the two nucleophiles the erythro-isomer is obtained.