Co-Tetraphenylporphyrin (co-TPP) in TM-TPP (TM = Fe, Co, Ni, Cu, and Zn) series: a new optical material under DFT.

A detailed investigation of the structure, electronic, spectroscopic, and optical properties of a series of transition metal-doped tetraphenylporphyrins (TM-TPP; TM = Fe, Co, Ni, Cu and Zn) is performed under density functional framework. The structure and stability of tetraphenylporphyrin (TPP) and TM-TPPs are understood with HOMO-LUMO gap, chemical hardness, and binding energies of the transition metals to the compound. Optical properties of TPP and TM-TPP series are assessed with relevant optical absorption spectra. A couple of visible active compounds, viz. Co-TPP and Ni-TPP, are reported for the first time for future opto-electronic applications. To gain insight on the possible synthesis of these compounds, we have analyzed frontier molecular orbitals (FMOs) as well as infra-red spectra. Graphical abstract Optical absorption spectra of TPP and TM-TPPs, and infrared spectra of TPP merged with Co-TPP.