Folded metallodendrons: shell-selective metal coordination and conformational properties

The synthesis, structure, and conformational properties of folded metallodendrons are described. The enhanced coordination ability of oxazoline-functionalized pyridyl-2,6-dicarboxamides, compared with pyridyl-2.6-diarylamides, permits unique metals to be installed at the peripheral and focal shells of the dendron. Circular dichroism (CD) studies and X-ray crystallography indicate that the intrinsic helical preference of the parent dendron is not perturbed by coordination. However, the CD spectra become insensitive to temperature due to an increase in structural rigidity that occurs upon metal coordination. [structure: see text]