Premium
Binuclear shift reagents. Structure and mode of interaction of Ag(fod)–Ln(fod) 3 with benzene
Author(s) -
Raber Douglas J.,
Hájek Milan
Publication year - 1986
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/mrc.1260240406
Subject(s) - chemistry , adduct , moiety , reagent , benzene , lanthanide , ion , crystallography , ring (chemistry) , medicinal chemistry , inorganic chemistry , stereochemistry , organic chemistry
Lanthanide‐tris(fod) reagents interact reversibly in solution with Ag(fod) to form binuclear adducts having the formula AgLn(fod) 4 . The formation constant ( K ) for AgYb(fod) 4 in CDCl 3 is 500 M −1 , and this equilibrium is in the slow exchange region below 20°C. Slow exchange is also found for AgDy(fod) 4 . The NMR data support a structure for the binuclear adduct consisting of an ion pair with a silver cation and a lanthanide‐tetrakis(fod) anion. The binuclear reagent associates weakly with benzene ( K = 3 M −1 ). The primary interaction involves coordination of the silver cation to the aromatic ring, and the tetrakis(fod) anion is situated in close proximity to the silver cation. Induced shifts for the aromatic moiety are primarily pseudo‐contact in origin.