Homogeneous CO Hydrogenation: Ligand Effects on the Lewis Acid ...

Figure S63. 11 B{ 1 H} NMR (broad underlying signal is borosilicate in probe construction).
General procedure for preparation of BAr F
4 salts of rhenium complexes.
The appropriate rhenium cation, bearing either a BF 4 or OTf counter anion, was dissolved in
CH 2Cl 2 solution (affording roughly 20 mM concentration) with stirring. Solid NaBArF 4 (1 equiv
relative to Re complex) was added, and the mixture stirred for at least 2 hours. Following
filtration, the solvents were removed from the filtrate in vacuo to afford powders or oils of the
rhenium BAr F
4 salts. If the product was oily, it was triturated with pentane to give a powder, and
the pentane was removed under vacuum. Yields were essentially quantitative, and spectroscopic
analysis correlated very favorably with the BF 4 or OTf starting materials, indicating that the
structure had not changed. 19 F NMR unequivocally showed removal of BF 4 or OTf, and
incorporation of BAr F
4 anion.
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