New type of cytotoxicity descriptors based on Cu(II) coordination ability of p-substituted phenols and subsequent O → Cu electron density transfer is introduced. Geometries of phenols and of their Cu(II) complexes are optimized at the DFT level of theory. The amount of electron density transfer is evaluated using the copper charge or the electron density Laplacian at the Cu-O bond critical point. The Cu-phenol interaction energy is a measure of the phenol reactivity. Statistical parameters for the linear dependence of the published cytotoxicity data on the above predictors are much better than the classical ones.

The geometries of monocharged and neutral octafluoro-spirobi[triphosphazene] in singlet, doublet and/or triplet ground spin states were optimized. Their electronic structures are investigated in terms of Quantum Theory of Atoms-in-Molecules and compared with neutral hexafluorocyclotriphosphazene. The change of the total molecular charge implies mainly the change of the properties of the nitrogen atoms which are bonded to the central spiro-phosphorus atom. The charged systems in singlet spin states have stable structures of D2d symmetry only unlike the remaining ones of C2 symmetry within two geometry types. The existence of the less symmetric structures can be fully explained as a consequence of the (pseudo-) Jahn-Teller effect.