title: Photorelease of carboxylic and amino acids from N-methyl-4-picolinium esters by mediated electron transfer.
abstract: One electron reduction of N-alkyl-4-picolinium (NAP) esters initiates C-O bond scission releasing a carboxylate anion. Previous experiments have demonstrated that this process can be initiated by photoinduced electron transfer from an electron-donating sensitizer. In the present study it is demonstrated that a comparable photorelease process can be initiated by photolysis of an electron acceptor (mediator), which in turn abstracts an electron from a ground state electron donor. The resulting mediator anion radicals donate an electron to the NAP ester, triggering release of the carboxylate anion. It is demonstrated that when benzophenone is used as a mediator, higher quantum yields for ester decomposition can be achieved compared with sensitizers that do direct photoinduced electron transfer.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742-2021, USA. falvey@umd.edu
authors.forename: Chitra
authors.initials: C
authors.lastname: Sundararajan
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Falvey
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects*; D002264:Carboxylic Acids / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects*; D004579:Electron Transport; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects*; D005609:Free Radicals / Q000138:chemical synthesis / Q000737:chemistry / Q000528:radiation effects; D007834:Lasers; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010777:Photochemistry; D010782:Photolysis; D011789:Quantum Theory
chemical_list: D000596:Amino Acids; D002264:Carboxylic Acids; D004952:Esters; D005609:Free Radicals