CARBONYL OXYGEN AS A HYDROGEN-BOND SUPER-BASE - THE AMIDATES

An infrared spectroscopic study of the 1:1 hydrogen-bond association o f amidates with both methanol and 4-fluorophenol showed that the site of complexation is the oxygen of the amidate function. However the for mamidate HCON(2)Me(3) forms a second 1:1 complex on the nitrogen of th e amidate, The formation constants of the hydrogen-bond complexes of t he amidates with the reference hydrogen-bond donor 4-FC6H4OH indicate that the amidates are stronger hydrogen-bond bases than are amides and amide vinylogues. As such, the amidates constitute the strongest carb onyl bases hitherto investigated on the hydrogen-bond basicity scale.