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1 H, 13 C and 15 N NMR studies on adducts formation of rhodium(II) tetraacylates with some azoles in CDCl 3 solution
Author(s) -
Bocian Wojciech,
Jaźwiński Jarosław,
Sadlej Agnieszka
Publication year - 2008
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.2149
Subject(s) - chemistry , rhodium , adduct , nuclear magnetic resonance spectroscopy , stereochemistry , organic chemistry , catalysis
Adduct formations of rhodium(II) tetraacetate and tetratrifluoroacetate with some 1H‐imidazoles, oxazoles, thiazoles, 1H‐pyrazoles and isoxazole have been investigated by the use of 1 H, 13 C, 15 N NMR and electronic absorption spectroscopy (VIS) in the visible range. Azoles tend to form axial adducts containing rhodium(II) tetraacylates bonded via nitrogen atom. Bulky substituents close to the nitrogen atom prevent the RhN bond formation, and in several cases switch over the binding site to the oxygen or sulphur atoms. The 15 N adduct formation shift Δδ( 15 N) (Δδ = δ adduct − δ ligand ) varied from ca − 40 to − 70 ppm for the nitrogen atom involved in complexation, and of a few parts per million only, from ca − 6 to 3 ppm, for the non‐bonded nitrogen atom within the same molecule. The Δδ( 1 H) values do not exceed one ppm; Δδ( 13 C) ranges from − 1 to 6 ppm. Various complexation modes have been proved by electronic absorption spectroscopy in the visible region (VIS). For comparison purposes, some adducts of pyridine, thiophene and furan derivatives have been measured as well. The experimental findings were compared with calculated chemical shifts, obtained by means of DFT B3LYP method, using 6‐311 + G(2d,p), 6‐31(d)/LanL2DZ and 6‐311G(d,p) basis set. Copyright © 2007 John Wiley & Sons, Ltd.