Geminal Bisphosphonate (BP) Esters in Ca(II) Ion Coordination. A series of geminal BPs was prepared starting from their corresponding ethyl- or isopropyl (arylmethylene)phosphonate ester precursors. Complexation with CaCl₂ yields the derived coordination compounds [Ca(H₂O)₂(L1–L3)₂]Cl₂ or [Ca(L8)Cl₂]ₙ. Their structures in the solid- (SCXRD) as well as solution-state (¹H DOSY NMR) are evaluated and comprehensively compared to literature data. The preparation and thorough characterization of a variety of (arylmethylene)phosphonate ester derivatives (S1–S7) as well as derived geminal bisphosphonate (BP) ester ligands (L1–L7) is presented. Subsequent complexation reactions of CaCl₂ with selected BPs (L1–L3) and a known aliphatic tetrakisphosphonate ester (L8) yield the respective Ca(II) coordination compounds [Ca(H₂O)₂(L1--L3)₂]Cl₂ (C1--C3) and [Ca(L8)Cl₂]ₙ (C4) for potential future application as multi-delivery systems in osteoporosis treatment. Obtained SCXRD and ¹H DOSY-NMR data provide a detailed insight into their solid- as well as solution-state structures extending the so far scarcely found X-ray studies on geminal BP-supported Ca(II) complexes.
@article{doi:10.17170/kobra-202206246402,
author ={Köhne, Ingo and Pietschnig, Rudolf},
title ={Synthesis of Geminal Bis- and Tetrakisphosphonate Ester Derivatives and Their Coordination Behavior Towards Ca(II) Ions},
keywords ={540 and Diphosphonate and Calcium and Koordinationslehre and Ligand and Phosphor and Strukturaufklärung},
copyright ={http://creativecommons.org/licenses/by/4.0/},
language ={en},
journal ={EurJIC (European Journal of Inorganic Chemistry)},
year ={2022-04-05}
}