Bake J G, Christian S D, Kim M H, Dryhurst G
Department of Chemistry, University of Oklahoma Norman, Oklahoma 73019, USA.
Biophys Chem. 1975 May;9(4):355-67. doi: 10.1016/0301-4622(75)80050-0.
The adsorption of a number of methylated uracil derivatives and of 5-fluorouracil has been studied by surface electrochemical methods at a mercury electrode. All derivatives exhibit an initial or dilute adsorption region where they are adsorbed flat on the electrode surface and are bound by pi-electron overlap with the electrode. Uracil, thymine, 1,5-dimethyl-uracil, 5,6-dimethyluracil, 1,5,6-trimethyluracil and 5-fluorouracil undergo a surface reorientation from the initial flat solution activities for each compound. An unsubstituted N(3)-H group is an absolute requirement for a uracil derivative to be capable of adopting the perpendicular surface stance. In the perpendicular orientation the uracil derivative appears to be bound to the electrode primarily via a N(3)-H--(-) electrode bond although a similar but weaker hydrogen bond can be formed via the N(1)-H group for certain compounds.
