Dramatically Enhanced Carbon Acidity of the Nitrobenzyl Fragment in a Nickel(II) Scorpionate Complex.

The -CH2- group of the 2-nitrobenzyl pendant arm of the scorpionate complex I deprotonates in basic aqueous solution (p Ka 10.6), due to the coordination of the nitronate group to the nickel(II) center. Metal coordination enhances 2-nitrobenzene acidity by 10 orders of magnitude.