E-mail: rbuechner uni-potsdam. E-mail: vinicius. The central moiety of porphyrins is shown to control the charge state of the inner complex and links it by covalent interaction to the peripheral substituents. This link, which enables the versatile functions of porphyrins, is not picked up in the established, reduced four orbital picture [Gouterman, J.
Systematic variation of the central moiety highlights two linked, governing trends: The ionicity of the porphyrin center increases from the aminic NβH to NβCu to NβZn to NβMg to the iminic N:. At the same time covalency with peripheral substituents increases and compensates the buildup of high charge density at the coordinated nitrogen sites.
However, optical spectroscopy of porphyrins is rather insensitive to electronic structure changes upon peripheral substitution or exchange of the central moiety.
To uncover the nature of the porphyrin transition beyond the Gouterman orbitals, density functional theory calculations are carried out for a range of functionals both with the transition potential TP-DFT and time dependent approach TD-DFT. Upon collision, the two jets form a liquid sheet, whose thickness can be adjusted to suit the penetration depth of soft X-rays. In the present study, a flow rate of 1. The continuous replenishment of the solutions also prevents radiation induced sample damage.
The bandwidth of the incoming X-rays was 0. BeckeβJohnson damping 22,23 was used for dispersion correction. For the simulation of the aqueous environment resulting in the spectra shown in Fig.
