Multiple isotope effects were measured at the reactive center of formamide during acid-catalyzed hydrolysis in water at 25 degrees C. The mechanism involves a rapid pre-equilibrium protonation of the carbonyl oxygen, followed by the formation of at least one tetrahedral intermediate, which does not appreciably exchange its carbonyl oxygen with the solvent (kh/kex = 55). The pKa for formamide was determined by 15N NMR and found to be about -2.0. The formyl-hydrogen kinetic isotope effect (KIE) is indicative of a transition state that is highly tetrahedral (Dkobs = 0.79); the carbonyl-carbon KIE (13kobs = 1.031) is in agreement with this conclusion. The small leaving-nitrogen KIE (15kobs = 1.0050) is consistent with some step prior to breaking the C-N bond as rate-determining. The carbonyl-oxygen KIE (18kobs = 0.996) points to attack of water as the rate-determining step. On the basis of these results, a mechanism is proposed in which attachment of the nucleophile to a protonated formamide molecule is rate determining.

By studying equity market returns to China, the UK, and the US, we explore the key question of whether the COVID-19 pandemic changes the risk exposure of equity markets, which is fundamental to market stability and investor confidence. Using data from the World Health Organization and Bloomberg, our full sample covers the period 3 July 2019 to 15 December 2020 which facilities a subsample (Normal, Shock, Endurance) analysis. Utilizing Value-at-Risk (VaR) metrics as our risk exposure measure, we find that 1) There exists a sharp increase in equity market risk exposure across the three equity markets. 2) A stronger pandemic impact is found in different market capitalization segments -China, large-cap; the UK, small-cap; the US, mid-cap. 3) Generally, investors consider the number of new cases as a more worrying factor than deaths while UK investors are sensitive to both. Our observations suggest that given limited resources but rising demands from both businesses and households for government assistance, a one-size-fits-all policy to support market recovery would be sub-optimal.

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