Solvent‐Mediated Transformation from Achiral to Chiral Nickel(II) Metal–Organic Frameworks and Reassembly in Solution |
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| Authors: | Prof Xiaoju Li Zhenjiang Yu Prof Xinxiong Li Xiaofang Guo |
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| Institution: | 1. Fujian Key Laboratory of Polymer Materials, College of Materials Science and Engineering, Fujian Normal University, Fuzhou, Fujian, 350007 (P.R. China);2. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002 (P.R. China) |
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| Abstract: | Reactions of 5‐nitroisophthalic acid (NO2‐H2ip), 1,4‐bis(imidazol‐1′‐yl)butane (bimb), and Ni(NO3)2 ? 6 H2O gave rise to four metal–organic frameworks (MOFs), Ni2(NO2‐ip)2(bimb)1.5]n ( 1 ), Ni4(NO2‐ip)3(bimb)2(OH)2(H2O)]n ? (CH3CH2OH)0.5 n ( 2 ), Ni(NO2‐ip)(bimb)1.5(H2O)]n ? (H2O)n ? (CH3CH2OH)0.5 n ( 3 ), and Ni(NO2‐ip) (bimb)(μ‐H2O)]n ? (H2O)n ( 4 ). The metal/ligand ratio, pH value, and solvent exerted a subtle but crucial influence on the formation of complexes 1 – 4 , which possess different visual color and crystal structures. Complex 1 exhibits a twofold interpenetrating 3D pillared bilayer framework composed of binuclear and mononuclear NiII units, whereas complex 2 is a 3D chiral network that consists of asymmetric tetranuclear NiII units. Complexes 3 and 4 are 3D layer‐pillared frameworks that consist of mononuclear NiII ions and a 3D six‐connected network of μ‐water‐bridged dinuclear NiII units, respectively. Interestingly, achiral 4 can be transformed into chiral 2 by using a solvent‐mediated single‐crystal‐to‐single‐crystal process without any chiral auxiliary. Magnetic analyses of 2 and 4 show the occurrence of antiferromagnetic interactions. Complex 3 is difficult to obtain directly as a single solid phase, but it can be homogeneously formed by solvent‐mediated transformations from 1 , 2 , and 4 . |
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| Keywords: | chirality metal– organic frameworks nickel solvent effects structural transformation |
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