Solvent effects on one‐bond BLi coupling constants in boryllithium compounds

EOM‐CCSD 11 B 7 Li coupling constants and B chemical shifts have been computed for Li‐diazaborole and its complexes with one H 2 O or FLi molecule. BLi coupling constants for a model compound H 2 BLi and its complexes with up to 4 H 2 O or FLi molecules have also been obtained in an attempt to resolve discrepancies between the computed values of these properties for isolated Li‐diazaborole and experimentally determined values for boryllithium in a THF solution. The presence of solvent molecules increases the ion‐pair character of the BLi bond, with the result that 1 J (BLi) decreases systematically as the basicity and the number of solvent molecules increases. In the presence of even a single solvent molecule, the boron chemical shift for Li‐diazaborole increases, and approaches the experimental value. The computed results emphasize the role of the solvent in determining these NMR properties. Copyright © 2007 John Wiley & Sons, Ltd.