Electrostatics and color: massive electrostatic perturbation of chromophores by ion cluster ligands

The SASAPOS protocol, a general reaction sequence allowing complete exchange of various neutral ligands X in organic, elementorganic, and inorganic systems by cationic ligands L+, has been applied to a variety of pentafluorophenyl-substituted dyes of the general formula C6F5-X=Y-D (X, Y = N, CH; D = donor substituted arene), yielding the corresponding polycationically substituted dyes. The perturbation of the chromophores by the massive electrostatic effects introduced via the SASAPOS method led to bathochromic shifts of the absorption maxima of up 140 nm, 7600 cm-1, respectively. A strong dependency of the specific shifts on the nature of the connecting pi linker -X=Y- (N vs CH) has been detected by UV-vis absorption spectroscopy. Additionally, the effects of resubstitution of cationic ligands L+ by OH and O- have been studied.