The synthesis and structure of trans-bis(methylnicotinate)aquatrichlorochromium(III).

The title complex was synthesized and its structure was determined by single crystal X-ray diffraction. There are four molecules per unit cell and the space group is $\text{P}$$\text{1}$. The methyl nicotinate ligands are bound in $\text{trans}$ positions through the nitrogen atoms. The average CrN distance is 2.094 Å and the average NCrN angle is 177.4 degrees. The average CrCl and CrO bond lengths (2.317 Å and 2.011 Å, respectively) are typical of many other structures. The coordination between methyl nicotinate and chromium may serve as a model for the proposed complex between nicotinic acid and chromium in glucose tolerance factor.     

Towards nanotubular structures with large voids: dynamic heteroleptic oligophenanthroline metallonanoscaffolds and their solution-state properties

The assembly of a rigid macrocycle with two exotopic phenanthroline binding sites in combination with linear bis- or trisphenanthrolines and copper(I) ions is used to generate nanoscale double and triple deckers, the latter showing a tubular structure. With supramolecular chemistry expanding to dynamic, large cavity, nanoscale structures, it becomes increasingly important to use robust assembly protocols as well as reliable characterization techniques. To fully elucidate and to describe the dynamic nature of metallonanoscaffolds with large voids, we applied a battery of both direct and indirect solution-state characterization methods. These methods along with the conventional direct methods provide a very useful tool for characterizing tubular nanoscaffold aggregates.     

Different types of self-avoiding walks on deterministic fractals

Normal and indefinitely-growing (IG) self-avoiding walks (SAWs) are exactly enumerated on several deterministic fractals (the Manderbrot-Given curve with and without dangling bonds, and the 3-simplex). On then th fractal generation, of linear sizeL, the average number of steps behaves asymptotically as N=AL ^D _saw+B. In contrast to SAWs on regular lattices, on these factals IGSAWs and normal SAWs have the same fractal dimensionD _saw. However, they have different amplitudes (A) and correction terms (B).