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The synthesis of five new dihalogen/interhalogen charge transfer adducts featuring cyano and nitro functionalized 1,3-dithiole-2-thiones have been prepared and characterized by x-ray crystallography. The structures feature a complex series of intermolecular close contacts between heteroatoms, as well as hydrogen bonding, to give highly ordered, polymeric assemblies. The adduct 4.IBr crystallizes in a noncentrosymmetric chiral space group and features a stack of molecules assembled through hydrogen bonds. The functional groups of all adducts participate in networks of close contacts, but do not affect the coordination environment of the dihalogen/interhalogen species.

An analysis is performed on the molecular and electronic features in a series of trigonal molecules constituted by a central truxene core which is ramified with three oligofluorene moieties of different lengths. Arms and core are studied independently and upon threefold unification. Special emphasis is paid to the modulation of the conjugational properties in relation to substitution, molecular dimension, ring aromaticity, intermolecular forces, oxidation state, etc. Raman and optical absorption/emission spectroscopies in conjunction with computational theoretical results are combined for this purpose. The evolution of some key intensity ratios in the Raman spectra (i.e., I(1300)/I(1235)) is followed as an indication of electronic interaction between the core and the branches. The changes of the electronic delocalization upon solvation, with varying temperature in the solid state, with the nature of the aromatic unit (bithiophene/fluorene) or after electrochemical oxidation are interpreted. The modulation of the optical properties on the basis of the structure and energetics of the orbital around the gap is also addressed. Density functional theory was used to assign the vibrational and electronic spectra.

The crystal structure of an iodine monobromide adduct of dimethyl 1,3-dithiole-2-thione-4,5-dicarboxylate reveals a layered polymeric network of donor and acceptor molecules linked primarily through S⋯I–Br charge-transfer and hydrogen bonded interactions.

Luminescent lanthanide complexes have been prepared by exploiting the interaction between lanthanide DO3A complexes and chromophore bearing carboxylates or phosphonates. This interaction can be utilised to probe the choice of sensitising chromophore suited to a given lanthanide. Furthermore, ternary complexes obtained from chromophore appended carboxylates dissociate in the presence of phosphate, while those obtained from phosphonates do not.