Photorelease of carboxylic acids, amino acids, and phosphates from N-alkylpicolinium esters using photosensitization by high wavelength laser dyes.
Visible light (>450 nm) is used to efficiently cleave carboxylic acids, amino acids, and phosphates from their N-methyl picolinium esters. Photolysis using pyrromethene dyes PM 546 and PM 597 and also coumarin 6 as photosensitizers effects release of carboxylic acids, N-protected amino acids, and phosphates in quantitative yields. The effective rate of photorelease by the dyes, Phiepsilon, was found to be as high as 4500 M-1 cm-1. The photorelease proceeds through photoinduced electron transfer from the dye sensitizers to the N-methyl picolinium group. Fluorescence quenching and laser flash photolysis experiments support the photoinduced electron-transfer mechanism.
Sundararajan
Chitra
C
Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA.
Falvey
Daniel E
DE
D000596:Amino Acids / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D003374:Coumarins / Q000737:chemistry; D010755:Organophosphates / Q000737:chemistry*; D010777:Photochemistry; D010847:Picolines / Q000737:chemistry*
D000596:Amino Acids; D002264:Carboxylic Acids; D004396:Coloring Agents; D003374:Coumarins; D010755:Organophosphates; D010847:Picolines