Magnetic Circular Dichroism of Porphyrin Lanthanide M3+ Complexes

0435032 - ÚOCHB 2015 RIV US eng J - Journal Article
Andrushchenko, Valery - Padula, Daniele - Zhivotova, E. - Yamamoto, S. - Bouř, Petr
Magnetic Circular Dichroism of Porphyrin Lanthanide M3+ Complexes.
Chirality. Roč. 26, č. 10 (2014), s. 655-662. ISSN 0899-0042. E-ISSN 1520-636X
R&D Projects: GA ČR GA13-03978S; GA ČR GAP208/11/0105; GA MŠMT(CZ) LH11033
Grant - others:GA AV ČR(CZ) M200550902
Institutional support: RVO:61388963
Keywords : magnetic circular dichroism * lanthanides * porphyrin complexes * density functional theory * sum over state computations
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 1.886, year: 2014

Lanthanide complexes exhibit interesting spectroscopic properties yielding many applications as imaging probes, natural chirality amplifiers, and therapeutic agents. However, many properties are not fully understood yet. Therefore, we applied magnetic circular dichroism (MCD) spectroscopy, which provides enhanced information about the underlying electronic structure to a series of lanthanide compounds. The metals in the M3+ state included Y, La, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu; the spectra were collected for selected tetraphenylporphin (TPP) and octaethylporphin (OEP) complexes in chloroform. While the MCD and UV-VIS absorption spectra were dominated by the porphyrin signal, metal binding significantly modulated them. MCD spectroscopy was found to be better suited to discriminate between various species than absorption spectroscopy alone. The main features and trends in the lanthanide series observed in MCD and absorption spectra of the complexes could be interpreted at the Density Functional Theory (DFT) level, with effective core potentials on metal nuclei. The sum over state (SOS) method was used for simulation of the MCD intensities. The combination of the spectroscopy and quantum-chemical computations is important for understanding the interactions of the metals with the organic compounds.
Permanent Link: http://hdl.handle.net/11104/0239042