Novel Sulfone 2-Aminobenzimidazole Derivatives and Their Coordination Compounds: Contribution of the Ethyl and Phenyl Substituents on Non-Covalent Molecular Interactions; Biological Antiproliferative Activity

New sulfone 2-aminobenzimidazole derivatives were designed and synthesized. Their nickel(II), copper(II), zinc(II), cadmium(II) and mercury(II) compounds were obtained and fully characterized by spectroscopic and analytical techniques. Single crystal X-ray structural analysis was performed in order to study the relevant intra and inter non-covalent interactions, mainly Hpi, lone pairpi, and pipi, highlighting the difference between the terminal ethyl and phenyl groups in such interactions. Dimeric and trimeric supramolecular syntons were found for some of these compounds. Additionally, their antiproliferative activity was investigated, finding that the copper(II) compounds with the sulfone phenyl derivative were the most active.