Past exam of the MPhil in micro- and nanotechnology enterprise course of the University of Cambridge / 2023 / Paper 1 / Section B / 10 / i / b / Solution

CNS-DDA contains an amide linkage, $\mathrm{surface}-\mathrm{C}(\mathrm{O})-\mathrm{NH}-{\mathrm{C}}_{12}{\mathrm{H}}_{25}$. The amine nitrogen becomes bonded to the surface carbonyl carbon.

CNS-EG contains an ester linkage, $\mathrm{surface}-\mathrm{C}(\mathrm{O})-\mathrm{O}-\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{OH}$. One alcohol group forms the ester while the other remains an outer hydroxyl group. The latter is not an ether linkage at the surface carbonyl.