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Simulation of 59 Co NMR Chemical Shifts in Aqueous Solution
Author(s) -
Bühl Michael,
Grigoleit Sonja,
Kabrede Hendrik,
Mauschick Frank T.
Publication year - 2005
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200500285
Subject(s) - molecular dynamics , polarizable continuum model , aqueous solution , chemistry , solvent , chemical shift , polarizability , computational chemistry , molecule , solvent effects , thermodynamics , physics , organic chemistry
59 Co chemical shifts were computed at the GIAO‐B3LYP level for [Co(CN) 6 ] 3− , [Co(H 2 O) 6 ] 3+ , [Co(NH 3 ) 6 ] 3+ , and [Co(CO) 4 ] − in water. The aqueous solutions were modeled by Car–Parrinello molecular dynamics (CPMD) simulations, or by propagation on a hybrid quantum‐mechanical/molecular‐mechanical Born–Oppenheimer surface (QM/MM‐BOMD). Mean absolute deviations from experiment obtained with these methods are on the order of 400 and 600 ppm, respectively, over a total δ ( 59 Co) range of about 18 000 ppm. The effect of the solvent on δ ( 59 Co) is mostly indirect, resulting primarily from substantial metal–ligand bond contractions on going from the gas phase to the bulk. The simulated solvent effects on geometries and δ ( 59 Co) values are well reproduced by using a polarizable continuum model (PCM), based on optimization and perturbational evaluation of quantum‐mechanical zero‐point corrections.