Sensing the chirality of Dawson lanthanide polyoxometalates [alpha1-LnP2W17O61]7- by multinuclear NMR spectroscopy.
Lanthanide complexes of the chiral Dawson phosphotungstate [alpha(1)-P(2)W(17)O(61)](10-) were used to study the formation of diastereomers with optically pure organic ligands. The present work started with the full assignment of the (183)W NMR spectra of [alpha(1)-Yb(H(2)O)(4)P(2)W(17)O(61)](7-) at different temperatures and concentrations, which allowed the structure of the dimerized form in aqueous solution to be established. Different enantiopure amino acids and phosphonic acids were screened as ligands. Both types allowed chiral differentiation by multinuclear NMR spectroscopy under fast-exchange conditions. Functional groups with a good affinity for the oxo framework of the polyoxometalate were identified, and maps of the interactions between L-serine and N-phosphonomethyl-L-proline with [alpha(1)-Yb(H(2)O)(4)P(2)W(17)O(61)](7-) were established. This demonstrates the power of (183)W NMR spectroscopy to elucidate the molecular recognition of inorganic molecules by organic compounds. N-Phosphonomethyl-L-proline appears to be a convenient ligand to promote separation of the diastereomers and ultimately resolution of the enantiomers of [alpha(1)-Yb(H(2)O)(4)P(2)W(17)O(61)](7-).
Laboratoire de chimie inorganique et matériaux moléculaires (UMR CNRS 7071), Institut de chimie moléculaire (FR 2769), Université Pierre et Marie Curie-Paris 6, Case courrier 42, 4 place Jussieu, Paris cedex 05, France.
Cécile
C
Boglio
Bernold
B
Hasenknopf
Géraldine
G
Lenoble
Pauline
P
Rémy
Pierre
P
Gouzerh
Serge
S
Thorimbert
Emmanuel
E
Lacôte
Max
M
Malacria
René
R
Thouvenot
D019281:Dimerization; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D011392:Proline / Q000737:chemistry; D012694:Serine / Q000737:chemistry; D013237:Stereoisomerism; D014414:Tungsten / Q000737:chemistry*
D028581:Lanthanoid Series Elements; D008024:Ligands; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D012694:Serine; D011392:Proline; D010100:Oxygen; D014414:Tungsten