209482-49-5Relevant academic research and scientific papers
Self-recognition of structurally identical, rod-shaped macroions with different central metal atoms during their assembly process
Yin, Panchao,Zhang, Jin,Li, Tao,Zuo, Xiaobing,Hao, Jian,Warner, Anna Marie,Chattopadhyay, Soma,Shibata, Tomohiro,Wei, Yongge,Liu, Tianbo
, p. 4529 - 4536 (2013)
Two rod-shaped macroanions, ((C4H9) 4N)7[Mo6O18NC(OCH2) 3XMo6O18(OCH2)3CNMo 6O18] (X = MnIII (1), FeIII (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.
Exploring the programmable assembly of a polyoxometalate-organic hybrid via metal ion coordination
Yin, Panchao,Li, Tao,Forgan, Ross S.,Lydon, Claire,Zuo, Xiaobing,Zheng, Zhaoxiong Norm,Lee, Byeongdu,Long, Deliang,Cronin, Leroy,Liu, Tianbo
, p. 13425 - 13432 (2013)
The conformational flexibility and programmed assembly of a dumbbell-shaped polyoxometalate-organic hybrid molecule comprising two Dawson-type polyoxometalates linked by a 2,2′-bipyridine unit, which can be coordinate to metal ions, in this case of Zn2+, are described. SAXS, UV/vis, and NMR spectroscopic techniques confirm that the hybrid molecules exist as the trans dumbbell in metal-ion-free solutions and can be reversibly transformed into the cis dumbbell through coordination upon the addition of ZnCl2 into a DMSO solution containing the hybrid. Subsequent addition of EDTA reverses the switching process by extracting the Zn2+ cations from the hybrid. During the interchange process between trans and cis dumbbells, a further reorganization of the hybrid molecules occurs through bond rotation to minimize steric clashes between the polyoxometalate subunits, in order to stabilize the corresponding dumbbell conformation. The Zn2+- controlled conformational transformation of the hybrid can be further utilized to manipulate the hybrid's solvophobic interaction-driven self-assembly behavior in the metal-ion driven reversible formation of 140 nm sized vesicles, studied by laser light scattering techniques.
