Ab initio powder X-ray diffraction structural analysis of bispidine based 1D coordination polymers: insights into...

Area of Science:

• Materials Science
• Crystallography
• Chemistry

Background:

• Coordination polymers (CPs) are versatile materials with tunable properties.
• Understanding the structural basis of dynamic behavior in CPs is crucial for designing advanced functional materials.
• Bispidine-based CPs represent a new family with potential applications in adsorption and separation.

Purpose of the Study:

• To determine the ab initio crystal structure of a bispidine-based one-dimensional (1D) coordination polymer (CP) using synchrotron powder X-ray diffraction (XRD).
• To establish a structural baseline for understanding the dynamic behavior, including solvent adsorption and exchange, in this class of materials.
• To investigate novel solvated phases and the thermal activation of dynamic adsorption properties.

Main Methods:

• Ab initio structure solution from synchrotron powder XRD data using real-space global optimization.
• Rietveld refinement for precise structural parameter determination.
• Single crystal and powder XRD analysis of novel solvated phases.

Main Results:

• The first ab initio structure solution for a bispidine-based 1D ribbon-like CP (1) was achieved.
• A non-dynamic phase of CP 1, devoid of solvent molecules, was characterized.
• Novel bisolvated phases (1·TCM·oNT, 1·TCM·pCT, 1·TCM·NB) were synthesized and structurally analyzed.
• It was demonstrated that CP 1 can be thermally activated to restore dynamic selective adsorption capabilities.

Conclusions:

• The detailed structural characterization of CP 1 provides a foundation for understanding its dynamic adsorption mechanisms.
• The ability to form and interconvert between solvated and non-solvated phases highlights the dynamic nature of these materials.
• Thermal activation offers a route to regaining and controlling the selective adsorption properties of bispidine-based CPs.