Solvent effect on the physical quenching of singlet molecular oxygen by p-quinones.
Rate constants for the interaction between singlet molecular oxygen [O2(1 delta g)] and the p-quinones 1,4-benzoquinone (BQ), duroquinone (DQ), 9,10-anthraquinone (AQ) and 1,8-dihydroxy-9,10-anthraquinone (OHAQ) are reported for several solvents at room temperature. The solvent effect on the total quenching rate constant (kt) was analysed employing the semiempirical solvatochromic equation proposed by Kamlet and Taft. The higher values of kt (2-7 x 10(7) M(-1) s(-1)) were obtained when the hydrogen-bond donor solvent ability is increased (higher alpha parameter values). The results indicate the importance of specific solvent interactions in governing the rates of the quenching.
Gutiérrez
María Isela
MI
Departamento de Química, Facultad de Ciencias Naturales, Universidad Nacional de la Patagonia San Juan Bosco 9000, Comodoro, Rivadavia, Argentina. isela@unpata.edu.ar
D015394:Molecular Structure; D010084:Oxidation-Reduction; D010777:Photochemistry; D011809:Quinones / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry; D026082:Singlet Oxygen / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
D011809:Quinones; D012997:Solvents; D026082:Singlet Oxygen; D012428:Ruthenium