title: Self-recognition of structurally identical, rod-shaped macroions with different central metal atoms during their assembly process.
abstract: Two rod-shaped macroanions, ((C4H9)4N)7[Mo6O18NC(OCH2)3XMo6O18(OCH2)3CNMo6O18] (X = Mn(III) (1), Fe(III) (2)), with almost identical charge densities and morphologies except for their different encapsulated central metal atoms were each observed to self-assemble into "blackberry"-type supramolecular structures in their dilute solution, driven by the counterion-mediated attraction. Amazingly, the two macroions remained self-sorted and self-assembled into homogeneous assemblies in their mixed solutions, demonstrating a self-recognition behavior between two highly similar macroions during their assembly process, as confirmed by DLS, SLS, and TEM/EDS analysis. This self-recognition behavior can be explained by the slightly different charge distributions of the macroanions resulting from their different central atoms (confirmed by theoretical DFT calculations and dissociation experiments) and the high activation energy of the slow assembly process, which suppresses the formation of hybrid oligomers at the beginning of the self-assembly process. This work confirms that the long-range counterion-mediated electrostatic attraction is sensitive to the small difference in macroions and consequently offers the possibility for delicate selectivity and preference among different macroions. This phenomenon might be directly related to (and be the important reason for) some recognition behaviors in biological systems.
authors: Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
authors: Panchao
authors: P
authors: Yin
authors: Jin
authors: J
authors: Zhang
authors: Tao
authors: T
authors: Li
authors: Xiaobing
authors: X
authors: Zuo
authors: Jian
authors: J
authors: Hao
authors: Anna Marie
authors: AM
authors: Warner
authors: Soma
authors: S
authors: Chattopadhyay
authors: Tomohiro
authors: T
authors: Shibata
authors: Yongge
authors: Y
authors: Wei
authors: Tianbo
authors: T
authors: Liu
mesh_terms: D007477:Ions / Q000737:chemistry*; D008027:Light; D008670:Metals / Q000737:chemistry*; D008958:Models, Molecular; D011789:Quantum Theory; D012542:Scattering, Radiation; D053838:Scattering, Small Angle; D055672:Static Electricity; D014961:X-Ray Diffraction
chemical_list: D007477:Ions; D008670:Metals