These observations are consistent with the 1 H NMR spectroscopic patterns and the electronic absorption spectra (decreasing molar absorption coefficient). The differences in the efficiency of π-delocalization in 21-carba-23-selenaporphyrin 9-I, ruthenocenoselenaporphyrin 11, and its dication 11-H2 2+ are readily apparent in NICS 2D maps. The EDDB contour plots and NICS 2D maps both demonstrate the π-delocalization across the 1,3-ruthenocene fragment. Analogous observations have been made for the bimetallic complex 15 and the control palladium complex 14 (Figure ). However, in this particular case, the strong deviation of the selenophene ring from the macrocyclic plane defined by the meso-carbon atoms contributes to a decrease in the π-conjugation efficiency.