Intermolecular Interactions in Crystals of the Photosensitive Coordination Compounds of Zinc(II)

The distribution of the electron density function in crystals of {[ZnBpe(Me2Mal)] · H2O}n (I) and [Zn(H2O)4Bpe2](HEt2Mal)2 (II) is obtained by the periodic DFT calculations. Under UV irradiation, compounds I and II transform into [Zn(Bpe)(Me2Mal)]2[Zn2(Тpcb)(Me2Mal)2] · H2O and {[Zn(H2O)4(Bpe)2]0.15[Zn(H2O)4(Tpcb)]0.85(HEt2mMal)4} (Bpe is 1,2-bis(4-pyridine)ethylene, Тpcb is 1,2,3,4-tetrakis(4-pyridine)cyclobutane, H2Me2Mal is dimethylmalonic acid, and H2Et2Mal is diethylmalonic acid), respectively. An analysis of intermolecular contacts using Bader’s “Atoms-in-Molecules” theory shows the bonding route and bond critical point between the carbon atoms of the adjacent 1,2-bis(4-pyridine)ethylene molecules. It is established that the common surface of the Voronoi–Dirichlet molecular polyhedra between the photosensitive fragments can serve as a criterion for the possible participation of the molecules in solid-phase photoinduced reactions.