Dendrimer structures, ESR analysis

In addition to CW ESR, ENDOR, and pulsed techniques (HYSCORE spectra, 2D-ESTN, and ESEEM) were also used for dendrimer analysis. The ESR techniques have provided useful information on the dendrimers structure, properties, and applications, and their interactions with selected species. 

As shown in this chapter, ESR provides a very useful technique for the study of dendrimer properties and their local environments, not only when paramagnetic species are directly involved in the dendrimer original structure, but also when paramagnetic units are added as spin probes or spin labels to the dendrimers. The advantage of the ESR technique with respect to other spectroscopic methods of analysis mainly resides in the ability to select the proper spin probe or spin label able to monitor, like a special camera, a selected area internally or externally to the dendrimer. Of course, the basic request is to know if and how the probes or the labels modily the dendrimer properties. 

Analysis of the ESR spectra of organic dendrimers containing paramagnetic metal ions is a useful tool to obtain information about structure, conformation, and interacting ability of dendrimers, and to assess different applications, mainly in the biomedical and electtonic fields. This section provides examples on the ESR studies carried out by using paramagnetic metal ions to probe the dendrimer properties. 

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