Tuning Spin-Spin Interactions in Radical Dendrimers

Vega Lloveras; Flonja Liko; Luiz F Pinto; José L Muñoz-Gómez; Jaume Veciana; José Vidal-Gancedo

doi:10.1002/cphc.201800372

Tuning Spin-Spin Interactions in Radical Dendrimers

Chemphyschem. 2018 May 10. doi: 10.1002/cphc.201800372. Online ahead of print.

Authors

Vega Lloveras^{1

2}, Flonja Liko¹, Luiz F Pinto^{1

2}, José L Muñoz-Gómez¹, Jaume Veciana^{1

2}, José Vidal-Gancedo^{1

2}

Affiliations

¹ Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), campus universitari de Bellaterra, E-, 08193, Cerdanyola del Vallès, Spain.
² Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain.

PMID: 29744989
DOI: 10.1002/cphc.201800372

Abstract

Two generations of polyphosphorhydrazone (PPH) dendrimers were synthesized and fully functionalized with TEMPO radicals via acrylamido or imino group linkers to evaluate the impact of the linker substitution on the radical-radical interactions. A drastic change in the way that the radicals interacted among them was observed by EPR and CV studies: while radicals in G_n -imino-TEMPO dendrimers presented a strong spin-spin interaction, in the G_n -acrylamido-TEMPO ones they acted mainly as independent radicals. This shows that these interactions could be tuned by the solely substitution of the radical linker, opening the perspective of controlling and modulating the extension of these interactions depending on each application. The chemical properties of the linker strongly influence the spin-spin exchange between pendant radicals.

Keywords: EPR; electrochemical properties; magnetic properties; radical dendrimers; spin-spin interactions.