Axial Coordinated Manganese(III) Porphyrin/Tetraazaporphyrin – 4‐(10‐phenylanthracen‐9‐yl)Pyridine Dyads: Self‐Assembly, Structure and Spectral Properties in Ground and Excited States

Abstract

Self‐assembly of new donor‐acceptor systems based on (5,10,15,20‐tetraphenylporphinato)manganese(III)/(5,10,15,20‐tetra‐4‐tert‐butylphenylporphinato)manganese(III)/(octakis(4‐tert‐butylphenyl)tetraazaporphinato)manganese(III) acetate ((AcO)MnTPP/(AcO)MnTBPP/(AcO)MnTAP) and 4‐(10‐phenylanthracen‐9‐yl)pyridine (PyAn) was studied using fluorescence spectroscopy and mass spectrometry. It was found that the coordination complexes of 1:1 composition (dyads) are formed in toluene. The spectral properties, the chemical structures and redox behavior of the dyads were described using 1H NMR, IR, EPR spectroscopy and cyclic voltammetry, respectively. The dynamic processes and the characteristics in the excited state of the dyads were obtained using the femtosecond transient absorption spectroscopy method. Density functional theory (DFT), time‐dependent DFT methods were used to elucidate the dyad electronic structures and to establish the differences in their frontier molecular orbitals. The analysis of the lambda parameter and the distance of hole‐pair interaction was indicated more favorable charge transfer between the macrocycle and the axial PyAn fragment in (AcO)(PyAn)MnTAP. The calculated values of the zero‐field splitting parameters D and E/D, together with the g tensors of the lowest spin‐orbit state for (AcO)MnTPP and (AcO)(PyAn)MnTPP were obtained using the combination of DFT and Multireference Perturbation Theory (CASSCF/NEVPT2) simulations. The data obtained develop the fundamental basis in the field of photovoltaics and show the prospects for the study of molecular systems of this class.