This page summarizes the optical absorption and emission data of Pyropheophorbide a that is available in the PhotochemCAD package, version 2.1a (Du 1998, Dixon 2005). I reworked their data to produce these interactive graphs and to provide direct links to text files containing the raw and manipulated data. Although I have tried to be careful, I may have introduced some errors; the cautious user is advised to compare these results with the original sources.
This optical absorption measurement of Pyropheophorbide a were made by M. Taniguchi on 10-03-2004 using a HP 8453. The absorption values were collected using a spectral bandwidth of 1.0 nm.
These measurements were scaled to make the molar extinction coefficient match the value of 45,000cm-1/M at 669.0nm (Zheng, 2002).
The fluorescence emission spectrum of Pyropheophorbide a dissolved in dichloromethane. The quantum yield of this molecule is 0.32 (Dixon, 2005). This spectrum was collected by on 10-03-2004 using a PTI QM-4/2003 SE. The excitation and emission monochromators were set at 0.25 mm, giving a spectral bandwidth of 1 nm. The data interval was 1 nm and the integration time was 1 sec.
Samples were prepared in 1cm pathlength quartz cells with absorbance less than 0.1 at the excitation and all emission wavelengths to uniformly illuminate across the sample, and to avoid the inner-filter effect. The dark counts were subtracted and the spectra were corrected for wavelength-dependent instrument sensitivity.
Dixon, J. M., M. Taniguchi and J. S. Lindsey (2005), "PhotochemCAD 2. A Refined Program with Accompanying Spectral Databases for Photochemical Calculations, Photochem. Photobiol., 81, 212-213.
Du, H., R.-C. A. Fuh, J. Li, L. A. Corkan and J. S. Lindsey (1998) PhotochemCAD: A computer-aided design and research tool in photochemistry. Photochem. Photobiol. 68, 141-142.
Wasielewski, M. R. and W. A. Svec (1980) Synthesis of covalently linked dimeric derivatives of chlorophyll a, pyrochlorophyll a, chlorophyll b, and bacteriochlorophyll a. J. Org. Chem. 45, 1969-1974.
Zheng, G., H. Li, M. Zhang, S. Lund-Katz, B. Chance and J. D. Glickson (2002) Low-density lipoprotein reconstituted by pyropheophorbide cholesteryl oleate as target-specific photosensitizer. Bioconjugate Chem. 13, 392-396.
© 5 March 2012 Scott Prahl