A molecular packing analysis of some ferrous porphyrin complexes

An analysis has been made of the applicability of various sets of nonbonded interaction potential parameters which do not consider hydrogen atoms explicitly, to represent molecular packing interactions in crystals of ferrous porphyrin complexes, which are models for deoxyhemoglobin. Ordered regions of the structures are well described, but disordered solvent or ligands cause difficulty.     

An NMR and solvation study of rotational isomerism in epihalohydrins

The ¹H NMR spectra of epifluoro, chloro- and bromohydrin have been analysed in a number of solvents of varying polarity. Ab initio and molecular mechanism calculations together with solvation theory allowed an analysis of the observed solvent dependence of the proton couplings in terms of the anti and gauche rotamers only, the syn rotamer being of very small population: The Ga che-anti energy difference in the vapour is 0.1, 0.5 and 0.7 kcal mol^-1 for the three compounds respectively, though these relative energies may be reversed in solutions in which the gauche form is relatively more stabilized. The trans-oriented vicinal coupling has values of 7.3, 8.4 and 9.1 Hz for F, Cl, and Br respectively. Only one long-range coupling showed a pronounced orientation dependence, due to an approximately planar zizag orientation in the gauche rotamer.     

An effect of silicon substitution remote from reactive site

The source of a rate retardation of the trimethylsilyl substituent in an alkylation reaction is probed.     

Hydrogen bonded complexes—II: The lactam-phenol ratios and structures in lactam-phenol complexes

Lactams form solid, isolable complexes with the three dihydroxybenzenes, 0,0'-biphenol and 2,3-naphthalenediol, in which lactam-phenol ratios of 1:1, 2:1, 3:1 and even 4:3 were observed. These ratios can be determined with precision by a gas chromatography method which is described. IR spectroscopy indicates that the bonds linking lactam and phenol are O-H...O and/or N-H...O hydrogen bonds Structures for the complexes are suggested.     

A model for gravity driven flow of a thin liquid-solid solution with evaporation effects

A vertical substrate is coated with a thin film of a solution consisting of a volatile viscous liquid and a solid solute. The liquid film thins under gravity while the volatile component simultaneously evaporates. We develop a model to predict the evolving film thickness and in so doing we develop an approximation for the later stages of the well-known dip-coating process.Received: October 10, 2003; revised: May 4 and July 19, 2004     

Reversal of chirality induced by ortho-methoxyl substitution of arylphosphine ligands in rhodium-catalysed asymmetric hydrogenation

o-Methoxyl substitution in DIOP(2) causes a reversal of configuration in asymmetric homogeneous hydrogenation of enamides.     

Homotopie für Okasche Paare von Garben homogener Räume

Ohne ZusammenfassungMeinem Lehrer, Herrn Professor Karl Stein, gewidmet zu seinem sechzigsten Geburtstag