Convergent synthesis of noncovalent metallodendrimers containing hydrophobic dendrons at the periphery.
The noncovalent synthesis of "layer-block" metallodendrimers containing hydrophobic shells of covalent dendritic wedges at the periphery is described. Starting from first- and second-generation Fréchet wedges having phosphines at their focal point, convergent dendritic growth yields third- and fourth-generation metallodendrimers in which the coordination of nitriles, pyridines, and phosphines to SCS Pd(II) pincers is used as the assembly motif. In this convergent growth, the number of terminal hydrophobic phosphine wedges increases with generation. The solubility of the dendritic structures in apolar organic solvents such as chloroform and dichloromethane increases accordingly, in contrast to previously reported metallodendrimers. All dendritic structures were characterized by (1)H and (31)P NMR spectroscopy, elemental analysis, and MALDI-TOF mass spectrometry.
van Manen
H J
HJ
Laboratory of Supramolecular Chemistry and Technology and MESA+ Research Institute, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
Fokkens
R H
RH
Nibbering
N M
NM
van Veggel
F C
FC
Reinhoudt
D N
DN