Singlet molecular oxygen quantum yield measurements of some porphyrins and metalloporphyrins
R Venkatesan N Periasamy T S Srivastava
Click here to view fulltext PDF
Permanent link:
https://www.ias.ac.in/article/fulltext/jcsc/104/06/0713-0722
Hematoporphyrin IX dimethyl ester (HPDME), tetraphenylporphyrin (TPP), tetra(4-methoxyphenyl)porphyrin (TMPP), tetra(3,4-dimethoxyphenyl)porphyrin (TDMPP), tetra(3,4,5-trimethoxyphenyl)porphyrin (TTMPP), tetraanthrylporphyrin (TAP) and tetraacridylporphyrin (TACP), and their Zn2+, SnX22+, Pd2+ and Pt2+ complexes have been prepared and characterized. The singlet molecular oxygen quantum yield (ϕΔ) values of the above porphyrins and their metal derivatives in N,N-dimethyl formamide (DMF) have been measured in the presence of 1,3-diphenylisobenzofuran (DPBF) as1O2 acceptor using steady state technique after correcting for the intensity of light absorbed by the photosensitizers. The ϕΔ values for the free base porphyrins are usually around 0.60. Hematoporphyrin IX dimethyl ester and its metal derivatives follow the order: HPDME (ϕΔ = 0.60) > Zn HPDME (0.40) > PdHPDME (0.34) > Sn(OH)2 HPDME (0.28) > PtHPDME (0.24). Zinc(II) complexes of tetraarylporphyrins show about 65% efficiency in ϕΔ values are compared to the ϕΔ values of their corresponding free base porphyrins. These results can be explained on the basis of catalyzed intersystem crossing to the ground state. The ϕλ values of the above free base porphyrins and their metal complexes in DMF in presence of DPBF using single-pulsed laser excitation technique follow similar trends.
R Venkatesan1 N Periasamy2 T S Srivastava1
Volume 135, 2023
All articles
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode
© 2022-2023 Indian Academy of Sciences, Bengaluru.