Carbon...carbon weak interactions.

A theoretical study of the complexes formed by systems with electron-deficient and electron-excessive carbon atoms was carried out using DFT and ab initio methods up to the CCSD(T)/aug-cc-pVTZ computational level. Stable complexes with interaction energies between -6.0 and -22.8 kJ mol(-1) were obtained that correspond to weak C...C interactions. The atoms in molecules analysis of the complexes confirmed the presence of these interactions. Natural energy decomposition analysis and electron localization function analysis were performed to gain further insight into the nature of the interaction. Polarization is the most important stabilizing term in these complexes.