Supramolecular polymers derived from the PtII and PdII schiff base complexes via C(sp2)–H ... Hal hydrogen bonding: Combined experimental and theoretical study.

Abstract A synthesis of the PdII and PtII N , N -diaryldiazabutadiene complexes and their self-assembly into infinite 1-dimensional chains in the solid state via rare C (sp2)–H ... Hal hydrogen bonding is reported. All the new compounds were characterized using elemental analyses (C, H, N), ESI-MS, IR, 1H and 13C NMR techniques and X-ray diffraction analysis. The nature and energies of intermolecular non-covalent interactions, which are responsible for the supramolecular polymerization, were studied theoretically using DFT calculations and topological analysis of the electron density distribution within the formalism of Bader's theory (QTAIM method). While chloro-complexes, which feature a relatively stronger C (sp2)–H ... Hal hydrogen bonding, form supramolecular polymers, the iodo-derivative does not self-assemble into 1-D chains due to the dominance of other crystal packing forces over the potential H⋯I contacts. Thus, the C (sp2)–H ... Hal HB can dictate a packing preference in the solid state and serve as a useful tool for supramolecular engineers. Graphical abstract Image 1 Highlights • Synthesis of the new PdII and PtII N , N -diaryldiazabutadiene complexes. • Self-assembly of the new complexes into 1-dimensional chains in the solid state via C (sp2)–H ... Hal hydrogen bonding. • X-ray diffraction analysis of the new materials. • Theoretical study of the nature and energies of intermolecular non-covalent interactions. [ABSTRACT FROM AUTHOR]