Crystal structures of transition and main group element 1,1-dithiolates are shown to be partially sustained by C–H⋯π(chelate) interactions. For the planar binary bisdithiocarbamates, C–H⋯π(MS₂C) interactions lead to aggregation patterns ranging from a 0-D four molecule aggregate to a 3-D architecture but with the majority of structures featuring 1-D or 2-D supramolecular assemblies.

Au⋯π interactions whereby the electron-rich π-system of C₆-aromatic rings interact with gold are shown to exist in the crystal structures of both gold(I) and gold(III) complexes, and have been revealed to occur between neutral/neutral, cationic/cationic, and cationic/anionic systems. Supramolecular aggregation facilitated by Au⋯π interactions leads to the formation of 0-dimensional aggregates, e.g. arising from an interaction between a gold complex and a solvent molecule, loosely associated spherical aggregates, e.g. cooperative interactions between centrosymmetrically related gold complexes, and even extended supramolecular polymeric chains of variable topology (e.g. linear, step ladder, and helical). The described Au⋯π interactions represent a new synthon in structural gold chemistry that should be considered in any complete analysis of their crystal structures.

A search of the Cambridge Structural Database (CSD) was performed to identify Te⋯π-aryl interactions not reported before in the literature. The examination of the distance between tellurium atoms and aryl group centroids and the analysis of crystal packing, using deposited crystal structure data, produced a list of organotellurium compounds which showed a variety of Te⋯π bonding interactions. These include inter-ionic Te⋯π interactions in anion–cation ion pairs, intramolecular Te⋯π-aryl interactions in mono- and di-nuclear covalent molecular compounds, as well as in dimeric and tetrameric supermolecules or in supramolecular polymeric arrays formed through secondary bonds. Most interesting was the finding that intermolecular Te⋯π aryl interactions can connect molecular tectons, leading to supramolecular self-assembly with formation of dimeric and polymeric superstructures. Finally, Te⋯π aryl interactions may interconnect polymeric chains formed through Te⋯X secondary bonds into 2D and perhaps 3D networks. Thus, the Te⋯aryl interactions appear as a new bonding motif for supramolecular self-assembly, which could be exploited for crystal engineering in organotellurium chemistry, i.e. for the design of new materials with attractive useful properties.

The complex [Cu₆(dmpymt)₆]·H₂O was synthesised by electrochemical oxidation of copper in an acetonitrile solution of the neutral ligand 4,6-dimethylpyrimidine-2-thione (Hdmpymt). The reaction of [Cu₆(dmpymt)₆] with 1,2-bis(diphenylphosphino)methane (dppm) and 1,2-bis(diphenylphosphino)ethane (dppe) yielded compounds of general formulae [Cu(dmpymt)(dppm)] and [Cu₂(dmpymt)₂(dppe)₃]. The molecular structure of [Cu₆(dmpymt)₆] was determined: the crystals are triclinic, space group P1, a= 11.432(3), b= 13.395(2), c= 15.694(4)Å, α= 80.28(2), β= 87.75(2), γ= 73.87(2)° and Z= 2. The six copper atoms are arranged with distorted-octahedral geometry, each copper atom being trigonally co-ordinated to one nitrogen and two sulfur atoms of three different ligands. Infrared, ¹H, ¹³C and ³¹P NMR spectral data are presented for all the compounds.