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pH and Salt-Assisted Macroscopic Chirality Inversion of Gadolinium Coordination Polymer
Ting Hou1, Lan-Qing Wu1, Yan Xu1,2
1State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China.
Researchers achieved macroscopic helical inversion in coordination polymers using pH and salt. This study demonstrates the first salt-assisted helical inversion in artificial systems, offering new ways to control material properties.
Area of Science:
- Coordination chemistry
- Supramolecular chemistry
- Materials science
Background:
- Controlling the handedness of helical architectures is crucial for regulating their functions.
- Macroscopic chirality inversion is well-established in organic systems but rare in coordination polymers (CPs).
- Salt-assisted macroscopic chirality inversion has not been previously reported in artificial systems.
Purpose of the Study:
- To investigate the role of pH and salt in regulating the morphology and helical sense of coordination polymers.
- To achieve macroscopic chirality inversion in CPs, specifically exploring salt-assisted methods.
Main Methods:
- Systematic investigation of coordination polymers (CPs) synthesized from Gd(NO3)3 and R-(1-phenylethylamino)methylphosphonic acid (R-pempH2).
- Modulation of pH to induce chirality inversion in the absence of additional nitrate ions.
- Addition of sodium nitrate (NaNO3) at a specific pH to observe salt-assisted helical inversion.
Main Results:
- Chirality inversion from left-handed to right-handed superhelices was achieved by adjusting pH from 3.2 to 3.8 without added nitrate.
- Addition of NaNO3 (2.0 eq) at pH 3.8 resulted in a complete inversion of chiral sense from left-handed to right-handed superhelices.
- This represents the first reported instance of salt-assisted macroscopic helical inversion in artificial systems.
Conclusions:
- pH is a critical factor in controlling the helical handedness of the studied CPs.
- The addition of salt (NaNO3) can effectively induce a macroscopic helical inversion, a novel finding.
- This work opens new avenues for designing and controlling chiral supramolecular architectures in coordination polymers.
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