NMR Study of Dendrimer Structures Using Paramagnetic Cobalt(II) as a Probe.
Cobalt(II) has been utilized as an external paramagnetic (1)H NMR probe for the study of the structure of dendrimers that possess specifically located metal recognition sites. The isotropically shifted (1)H NMR signals of the Co(II) complexes of two 2,6-diamidopyridine-containing dendrimers have been fully assigned by means of 1D and 2D NMR techniques, including NOE difference, EXSY, COSY, and TOCSY. T(1) values of the isotropically shifted signals were used to calculate metal-proton distances to build a molecular model of the internal structure of the dendrimers. The presence of sizable cavities within the dendrimers was observed, including a loosely packed conformation for the 2,6-diamidopyridine moiety to bind to potential guest molecules.
Epperson
Jon D.
JD
Department of Chemistry, Institute for Biomolecular Science, and Center for Molecular Design & Recognition, University of South Florida, Tampa, Florida 33620-5250.
Ming
Li-June
LJ
Woosley
Barry D.
BD
Baker
Gregory R.
GR
Newkome
George R.
GR