The remarkable propensity for the formation of C-H•••π(chelate ring) interactions in the crystals of the first-row transition metal dithiocarbamates and the supramolecular architectures they sustain

The Cambridge Crystallographic Database has been searched for the presence of intermolecular C-H center dot center dot center dot pi(chelate ring) interactions, known to be stabilising, in the crystals of the first-row transition metal dithiocarbamates, i.e. containing anionic ligands of the type -S2CNR2, R = H, alkyl and aryl. A significant propensity to form C-H center dot center dot center dot pi(chelate ring) interactions is noted, especially in crystals of nickel and copper dithiocarbamates. The participating hydrogen atoms are characterised as being near an electronegative atom/substituent encouraging their engagement in this supramolecular synthon. The survey shows that an open, square-planar geometry is not a prerequisite for a C-H center dot center dot center dot pi(chelate ring) interaction but, allows, on average, more of these contacts leading to one- and two-dimensional architectures. It is concluded that a search for a C-H center dot center dot center dot pi(chelate ring) supramolecular synthon should be included in any detailed analysis of the molecular packing of metal-containing crystals.