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Published on: April 14, 2020
Pressure-Induced Coordination Number Transition in Lanthanide Mellitate Coordination Polymers: Structure and
Nicholas Beck1, Daniela Gomez Martinez1, Thomas E Albrecht-Schönzart2
1Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States.
Abstract:
High external pressure is found to induce a non-coordinated water molecule to bond to cerium in a previously studied mellitate coordination polymer, as determined by high-pressure single-crystal X-ray diffraction, resulting in a coordination number transition at 3.85 GPa from 9 to 9.5 where half the cerium ions are 10-coordinate. Also, bond length changes due to increased pressure are experimentally measured, whereas the cerium-carboxylate bond lengths overall change by -0.004(9) Å/GPa, the cerium-water bonds by -0.016(3) Å/GPa, and cerium-oxygen bonds overall by -0.010(6) Å/GPa, which corresponds well with theoretical bond length decreases determined for similar compounds. The high-pressure absorbance spectra of the analogous neodymium mellitate are examined and compared with the structural changes observed.
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