Synthesis, structural analysis, and visualization of a library of dendronized polyphenylacetylenes.

A library of eleven high cis-content cis-transoidal polyphenylacetylenes (PPAs) dendronized with self-assembling dendrons was prepared from a library of fifteen convergently synthesized macromonomers. Using [Rh(C triple bond CPh)(nbd)(PPh(3))(2)] (nbd=2,5-norbornadiene) in the presence of 10 equiv of N,N-dimethylaminopyridine, predictive control over molecular weight and narrow molecular weight distribution are obtained. The PPA backbone serves as a helical scaffold for the self-assembling dendrons.

Polyvalent interactions in unnatural recognition processes.

The synthesis of two cluster compounds, one containing six secondary dialkylammonium ion centers and the other possessing six benzo-m-phenylene[25]crown-8 (BMP25C8) macrocycles, both appended to hexakis(thiophenyl)benzene cores, is described. The binding of these clusters with complementary mono- and divalent ligands is investigated with NMR spectroscopy to probe polyvalency in these unnatural recognition systems. The ability of the two different families of clusters to bind complementary monovalent ligands is compared with that of the monovalent receptor pair, namely the dibenzylammonium ion and BMP25C8.

A mechanically interlocked bundle.

The prototype of an artificial molecular machine consisting of a trisammonium tricationic component interlocked with a tris(crown ether) component to form a molecular bundle with averaged C(3v) symmetry has been designed and synthesized. The system is based on noncovalent interactions, which include 1) N(+)-H..

Controlling multivalent interactions in triply-threaded two-component superbundles.

We have investigated the (1)H NMR spectra, the absorption spectra, the fluorescence spectra and decays, and the electrochemical properties of i). a tritopic receptor in which three benzo[24]crown-8 macrorings are fused onto a triphenylene core, ii). a trifurcated trication wherein three dibenzylammonium ions are linked 1,3,5 to a central benzenoid core, and iii).