Atomically precise surface chemistry of zirconium and hafnium metal oxo clusters beyond carboxylate ligands

The effectiveness of nanocrystals in many applications depends on their surface chemistry. Here, we leverage the atomically precise nature of zirconium and hafnium oxo clusters to gain fundamental insight into the thermodynamics of ligand binding. Through a combination of theoretical calculations and experimental spectroscopic techniques, we determine the interaction between the M6O88+ (M = Zr, Hf) cluster surface and various ligands: carboxylates, phosphonates, dialkylphosphinates, and monosubstituted phosphinates. We refute the common assumption that the adsorption energy of an adsorbate remains unaffected by the surrounding adsorbates. For example, dialkylphosphinic acids are too sterically hindered to yield complete ligand exchange, even though a single dialkylphosphinate has a high binding affinity. Monoalkyl or monoaryl phosphinic acids do replace carboxylates quantitatively and we obtained the crystal structure of M6O8H4(O2P(H)Ph)12 (M = Zr, Hf), giving insight into the binding mode of monosubstituted phosphinates. Phosphonic acids cause a partial structural reorganization of the metal oxo cluster into amorphous metal phosphonate as indicated by pair distribution function analysis. These results rationalize the absence of phosphonate-capped M6O8 clusters and the challenge in preparing Zr phosphonate metal–organic frameworks. We thus further reinforce the notion that monoalkylphosphinates are carboxylate mimics with superior binding affinity.

Keywords

Subject (DDC)

500 - Naturwissenschaften und Mathematik

Project

Event

Exhibition start date

Exhibition end date

Conference start date

Conference end date

Date of the last check

ISBN

ISSN

2041-6520
2041-6539

Language

English

Created during FHNW affiliation

Yes

Strategic action fields FHNW

Publication status

Published

Review

Peer review of the complete publication

Open access category

Gold

License

Citation

Unniram, A., Pokratath, R., Parammal, M. J., Dhaene, E., Van den Eynden, D., Balog, S., Prescimone, A., Infante, I., Shahgaldian, P., & De Roo, J. (2024). Atomically precise surface chemistry of zirconium and hafnium metal oxo clusters beyond carboxylate ligands. Chemical Science, 15(42), 17380–17396. https://doi.org/10.1039/d4sc03859b

Full item page