Abstract
The prepn. and ESR spectroscopy of a series of fully functionalized poly(propylenimine) dendrimers (DAB-dendr-(NH2)n; n = 2, 4, 8, 16, 32, 64) with 3-carboxy-PROXYL radical end groups is described. The pendant nitroxyl end groups exhibit a strong exchange interaction. As a consequence, the ESR spectrum directly reveals the no. of end groups from the splitting between the hyperfine transitions for the lower generations. For the higher generations an increasingly exchanged-narrowed ESR spectrum is obsd. The temp. and solvent dependency of the exchange interaction is used to assess the dynamic behavior of the dendritic branches. FT-IR spectroscopy shows that a hydrogen-bonded network between the amide functionalities is present, consistent with the obsd. solvent effect on the ESR spectra
Original language | English |
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Pages (from-to) | 1959-1960 |
Journal | Chemical Communications, ChemComm |
Volume | 1997 |
Issue number | 20 |
DOIs | |
Publication status | Published - 1997 |