Crystallization of triple- and quadruple-stranded dinuclear bis-β-diketonate-Dy(iii) helicates: single molecule magnetic behavior

Abstract

Helical structures are vital in chemistry and biochemistry and their importance has been reconsidered since the structure of DNA was revealed. Over the past decades, the advantages of the helical structures of bis-β-diketonate-based multiple-stranded Ln³⁺ complexes have been speculated with respect to their unique structures. Based on our previous study, we have designed a V-shaped bis-β-diketone ligand, H₂MBDA, which has been utilized to crystallographically synthesize triple-stranded and quadruple-stranded dinuclear Dy³⁺ complexes. In contrast to the absence of crystallographical results in previous studies, the successful crystallization in this study has contributed to the functionalization of the –CF₃ groups into the ligand as the termini, which have played a key role in the crystallization through intermolecular weak interactions. Both complexes display slow magnetic relaxation. The auxiliary ligand, phenanthroline, contributes to both tuning the structure and strengthening the anisotropy barrier.