2‐Iminoimidazoline — starke Stickstoffbasen als Koordinationspartner in der Anorganischen Chemie

2‐Iminoimidazolines — Strong Nitrogen Bases als Ligands in Inorganic Chemistry Due to the tendency of the 5‐membered cyclic fragment to accept a positive charge which yields an ylide type bonding situation, 2‐iminoimidazolines are strong nitrogen bases. They can serve as neutral ligands being 2+2 electron donors. Deprotonation leads to the anions which are potential 2+4 electron donors. We describe first the synthesis and characterization of the title compound 2‐imino‐1, 3‐dimethylimidazoline (ImNH, 8 ) and its anion 9 . Next we demonstrate their properties as ligands in complexes of main group elements and transition metals. In a third chapter we describe attempts to functionalize iminoimidazolines with the goal to create neutral ligands that coordinate in a semistable fashion. On this way we want to make a contribution to the chemistry of complex compounds directed towards catalysis.     

Copper and iron interactions with angiotensin-converting enzyme inhibitors. A study by fast-atom bombardment tandem mass spectrometry

Fast atom bombardment, combined with high-energy collision-induced tandem mass spectrometry, has been used to investigate gas-phase metal-ion interactions with captopril, enalaprilat and lisinopril, all angiotensin-converting enzyme inhibitors.Suggestions for the location of metal-binding sites are presented. For captopril, metal binding occurs most likely at both the sulphur and the nitrogen atom. For enalaprilat and lisinopril, binding preferably occurs at the amine nitrogen. Copyright 1999 John Wiley & Sons, Ltd.     

Synthese und Struktur von [ImNCS2K] (ImN = 1,3-Dimethylimidazolin-2-imino): ein neuartiges Kaliumdithiocarbiminat

Synthesis and Structure of [ImNCS₂K] (ImN = 1,3-Dimethylimidazoline-2-imino): a Novel Potassium Dithiocarbiminate The reaction of the 2-iminoimidazoline 4 with KMe gives the potassium imidate 7 from which the potassium 1,1-dithiolate 8 is obtained in almost quantitative yield. Crystals of C₆H₈N₃S₂K · 1/6 CH₃CN ( 8 · 1/6 CH₃CN) are triclinic, space group P1 , Z = 6, a = 10.988(4), b = 13.597(8), c = 13.622(9) Å, α = 113.003, β = 105.53(3), γ = 105.62(3)°, V = 1636.90 ų. The structure consists of a complicated 3-dimensional framework in which the K₂ units bridged by the four sulfur atoms of two thiolate ligands are connected by nitrogen and sulfur bridges.     

Determination of loads applied perpendicularly to the outer boundary of a ring using coefficients of influence

A procedure is explained to determined the amount of several pairs of diametrical loads applied to the outside boundary of a ring when stresses at selected points of the inside or outside boundaries are known. Coefficients of influence are used, following an approach similar to the one presented in a previous paper. Examples of application are given and the possible increase in precision is shown when the number of points of measurements is larger than the number of loads to be determined.