Extended Data Fig. 2: Measurement and modelling of bulk formose reaction kinetics.

a, Formaldehyde (C1) concentration measured using the Nash method (conversion of formaldehyde to Hantzsch pyridine)⁶³ versus time for three independent bulk reactions using standard formose reagents and 0.2 M C2, incubated at 40 °C (Nash data) plus the curve for the best fit of the toy model (best fit) (\({k}_{{add}}\) = 2.8 M⁻¹.min⁻¹ and \({k}_{{cleave}}\) = 0.06 min⁻¹), and curves with \({k}_{{add}}\) and \({k}_{{cleave}}\) increased and decreased by 2-fold, and with \({k}_{{add}}\) increased by 4-fold. Note that the best overall fit (black curve) tends to slightly underestimate formaldehyde consumption between 5 to 10 minutes, whereas a 4-fold increase in \({k}_{{add}}\) (dotted black curve) more closely predicts the data. This indicates that \({k}_{{add}}\) is not determined accurately within this range, consistent with the experimental data for coupled formose droplets where the best fit of the toy model is found with a 4-fold increase in \({k}_{{add}}\) (Fig. 1e). These fitted values are consistent with those determined previously under similar conditions²⁵. In particular, we recover the ratio \({k}_{{add}}/{k}_{{cleave}}={k}_{1}/{k}_{3}=\) 47. We also have \({{k}_{{add}}=[{{\rm{OH}}}^{-}]k}_{1}\) and \({{k}_{{cleave}}=[{{\rm{OH}}}^{-}]k}_{3}\) from²⁵, where \({k}_{1}=\,\) 2.98 M⁻² min⁻¹ and \({k}_{3}=\) 0.2 M⁻¹min⁻¹. We recover our fitted values for [OH⁻] = 0.44 M, consistent with our conditions with 1 M of the superbase TMG where \(\left[{{\rm{OH}}}^{-}\right]\approx \,\) 1 M. b, As a, but showing the best fit of the toy model without and with the Cannizzaro reaction (no Cannizzaro and Cannizzaro, respectively) with the rate constant \({k}_{{can}}\) = 5.6 × 10⁻³ [OH⁻] = 2.5 × 10⁻³ M⁻¹ min⁻¹ from²⁵ using [OH⁻] = 0.44 M for consistency as above. c, Density of glycolaldehyde (C2) as a function of concentration, showing the linearity of excess density with concentration. See also Source Data.

Source data