The conformational polymorphism and weak interactions in solid state structures of ten new monomeric and dimeric substituted dibenzyldimethylammonium chloridopalladate salts

In this study, ten new dibenzyldimethyl/ethyl ammonium chloridopalladate(II) compounds with five different cations and two anions have been synthesized and a simple method for a synthesis, in which hydrochloric acid solutions are used, has been described. Furthermore, twelve structures including two polymorphs have been obtained from hydrochloric and methanol/acetonitrile solutions. The anion–cation and cation–cation interactions of the synthesized compounds have been studied mainly by means of single X-ray diffraction in order to study the effects of varying either the anion or the cations in these QA₂PdCl₄ and QA₂Pd₂Cl₆ salts. The results indicate that the effects of intermolecular cation–cation ππ and C–Hπ interactions induce distinct cation pairing in the structures where cations occupy the W-conformation. Moreover, the conformational changes in the cations, i.e. either the twisted/w conformations or parallel/antiparallel positions of the phenyl substituents, are found to induce polymorphism in these compounds. All structures are found to be stabilized by anion–cation C–HCl interactions.