Self‐Recognition Between Two Almost Identical Macroions During Their Assembly: The Effects of pH and Temperature |
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| Authors: | Fadi Haso Dr. Dong Li Somenath Garai Dr. Joseph M. Pigga Prof. Dr. Tianbo Liu |
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| Affiliation: | 1. Department of Polymer Science, University of Akron, Akron, OH 44325‐3909 (USA) http://gozips.uakron.edu/～tliu/;2. Department of chemistry, Lehigh University, 6 E. Packer Ave. Bethlehem, PA. 18015 (USA);3. Fakult?t für Chemie, Universit?t Bielefeld, Postfach 100131, 33501 Bielefeld (Germany) |
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| Abstract: | Two Keplerate‐type macroions, [MoVI72FeIII30O252‐ (CH3COO)12{Mo2O7(H2O)}2{H2Mo2O8(H2O)}(H2O)91]?ca. 150 H2O= {Mo72Fe30} and [{Na(H2O)12}?{MoVI72CrIII30O252(CH3COO)19‐ (H2O)94}]?ca. 120 H2O= {Mo72Cr30} , with identical size and shape but different charge density, can self‐assemble into spherical “blackberry”‐like structures in aqueous solution by means of electrostatic interactions. These two macroanions can self‐recognize each other and self‐assemble into two separate types of homogeneous blackberries in their mixed dilute aqueous solution, in which they carry ?7 and ?5 net charges, respectively. Either adjusting the solution pH or raising temperature is expected to make the self‐recognition more difficult, by making the charge densities of the two clusters closer, or by decreasing the activation energy barrier for the blackberry formation, respectively. Amazingly, the self‐recognition behavior remains, as confirmed by dynamic and static light scattering, TEM, and energy dispersive spectroscopy techniques. The results prove that the self‐recognition behavior of the macroions due to the long‐range electrostatic interaction is universal and can be achieved when only minimum differences exist between two types of macroanions. |
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| Keywords: | macroions polyoxometalates self‐assembly self‐recognition |
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