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207 Pb, 13 C and 1 H Nuclear Magnetic Resonance Studies of Lead(IV) Carboxylates in Solution
Author(s) -
Claridge T. D. W.,
Nettleton E. J.,
Moloney M. G.
Publication year - 1997
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/(sici)1097-458x(199703)35:3<159::aid-omr51>3.0.co;2-p
Subject(s) - chemistry , lead (geology) , resonance (particle physics) , nuclear magnetic resonance , radiochemistry , atomic physics , physics , geomorphology , geology
Lead(IV) reagents are widely used for the mediation of oxidation and carbon–carbon bond‐forming reactions, which are postulated to proceed by mechanisms involving ligand exchange processes at the metal centre. This paper reports multinuclear ( 207 Pb, 13 C and 1 H) magnetic resonance studies on lead(IV) carboxylates containing acetate, benzoate and cinnamate ligands, either as single‐ligand (PbX 4 ) or as mixed‐ligand (PbX m Y n ) species. At ambient probe temperatures ( ca . 300 K), averaged spectra were observed for all solution species, arising from rapid intermolecular ligand exchange. At 225 K, exchange was sufficiently slow for mixed‐ligand complexes, of general formula PbX 2 Y 2 , to exhibit spectra of five distinct complexes, which were shown to correspond to PbX m Y 4‐m( m =0–4). Analysis of the low‐temperature spectra presented an overall picture of chemical shift changes throughout the complexes when ligand exchange takes place. These data provide some insight into the behaviour of these complexes in solution which help explain the observed chemistry of more elaborate lead(IV) carboxylates. © 1997 by John Wiley & Sons, Ltd.