engleski

Continuous-wave EPR study of MOF-525 and PCN-223 doped with copper(II) ion as the metal center

The magnetic properties of metal-organic frameworks MOF-525 and PCN-223 doped with copper (II) ions were examined by continuous wave (CW) EPR spectroscopy. MOF-525 and PCN-223 have different topologies:MOF-525 cuboctahedron and PCN-223 hexagonal prism. [1] Simulations of experimental spectra were done assuming axial symmetry of g- and A- hyperfine tensors while all four nitrogens in the porphyrin ring were assumed equivalent. The following copper electron spin (S = 1/2) interactions with the nuclear spins were considered: hyperfine interaction with the copper nucleus spin (I = 3/2) and superhyperfine interaction with four neighbouring nitrogen nuclei spins (I = 1). [2] Fullerene was incorporated to PCN-223 in order to study its influence to spintronic properties. From the simulations of the experimental data we can see that the CW- EPR spectra of MOF-525 and PCN- 223 exhibit different hyperfine tensors, that superhyperfine lines are more pronounced if copper ions are more diluted and that fullerene is incorporated into the structure of PCN-223. Simulations were obtained using EasySpin software. [3] [1] B.Karadeniz et al., J. Am. Chem. Soc. 141 49 (2019) 19214. [2] C.Finazzo et al., Phys. Chem. Chem. Phys. 8 (2006) 1942. [3] S. Stoll, A. Schweiger, J. Magn. Reson. 178 1 (2006) 42.

metal organic frameworks ; copper ; continuous-wave EPR spectroscopy

nije evidentirano