Unprecedented {dz2-CuIIO4}⋯π-hole interactions: the case of a cocrystal of a Cu(II) bis-β-diketonate complex with 1,4-diiodotetrafluoro-benzene

Cocrystallization of a bis[1-(4-pyridypbutane-1,3-dionato]copper(ii) (1) complex and 1,4-diiodoperfluorobenzene in the presence of pyridine yields a 1:1 cocrystal where both the sigma and pi-holes of 1,4-diiodoperfluorobenzene play a role. The crystal structure shows short arene CuO4 center dot center dot center dot pi-hole stacking contacts, where the (d(z2)-(CuO4)-O-II) moiety functions as an integrated five-center pi-hole acceptor. DFT calculations combined with quantum theory of atoms-inmolecules and noncovalent interaction plot analyses corroborated the structure-defining role of the (d(z2)-(CuO4)-O-II)center dot center dot center dot pi-hole contacts.