Self-Assembly of an [M8 L24 ]16+ Intertwined Cube and a Giant [M12 L16 ]24+ Orthobicupola

Abstract

Through coordination-driven self-assembly, aesthetically captivating structures can be formed by tuning the length or flexibility of various components. The self-assembly of an elongated rigid terphenyl-based tetra-pyridyl ligand (L1) with a cis-Pd(II) acceptor produces an [M₁₂ L1₆ ]²⁴⁺ triangular orthobicupola structure (1). When flexibility is introduced into the ligand by the incorporation of a -CH₂ - group between the dipyridylamine and terphenyl rings in the ligand (L2), anunique [M₈ L2₄ ]¹⁶⁺ water-soluble 'intertwined cubic structure' (2) results. The inherent flexibility of ligand L2 might be the key factor behind the formation of the thermodynamically stable and 'intertwined cubic structure' in this scenario. This research showcases the ability to design and fabricate novel, topologically distinctive molecular structures by a straightforward and efficient approach.

Keywords: Cage Compounds; Orthobicupola; Palladium(II); Ravel Motif; Self-Assembly.