A suspected derivative morphology for pheophytin and the enhanced hydrogen decomposition it caused
A new class of unorthodox morphologies of pheophytin, called the semi- and fully-derivative forms, was suspected to have existed all along in the electron transfer pathway of photosystem-II (PS-II) in plants. More importantly, as likely a natural pre-form of the latter, the semi-derivative morphology was further conjectured to play a catalytic role in the hydrogen fuel cells owing to its particular structural features. In this research, the proposed new class of derivative morphologies was speculated to be energetically more favorable, than the orthodox one in textbooks, in supporting a proton current within its porphyrin ring and in interacting with hydrogen gas molecules. This supposition appeared to be viable according to the spectral comparison among results from 1st-principle quantum calculations, measurements and literatures, as well as to the need for a proton current to address existing NMR spectra of pheophytin. Then, indirect proof of existence of such derivative’s features was provided by our experimental effort that pheophytins could efficiently getter hydrogen gas. Lastly, processed pheophytin samples were experimentally shown to be capable of catalyzing the hydrogen decomposition in fuel cells.
KeywordsCatalysis Porphyrin ring Pheophytin Proton transport Derivative morphology of pheophytin
The authors acknowledge the full financial support of ARBL for this research work.
The manuscript was written through contributions of all authors.
Compliance with ethical standards
Conflict of interest
The authors declare no competing financial interest.
- A quantum mechanical simulation code (2003) of Accelry’s Material Studio to simulate physical, chemical, and optical properties of molecules and compounds based on the density functional theory (DFT). In it, generalized gradient approximation (GGA) PW91scheme for exchange correlation, and the double numerical plus d-function (DND) all-electron basis set, as well as the SCF (self-consistent field) tolerance of 1 × 10−5 eV were employed. During the geometry optimization for minimum Hamiltonian calculations, the approach of “Partial Structural Constraint Path Minimization” (PSCPM) was adoptedGoogle Scholar
- Arvola, L.: Spectrophotometric determination of chlorophyll a and phaeopigments in ethanol extractions. Ann. Bot. Fenn. 18, 221–227 (1981)Google Scholar
- Dere, S., Gunes, T., Sivaci, R.: Spectrophotometric determination of chlorophyll-A, B and total carotenoid contents of some algae species using different solvents. Trans. J. Bot. 22, 13–17 (1998)Google Scholar
- Hopkins, W.G., Hüner, N.P.A.: Introduction to Plant Physiology, 4th edn, pp. 114–119. Wiley, Hoboken (2008)Google Scholar
- Kadish, K.M., Smith, K.M., Guilard, R.: Handbook of Porphyrin Science: With Applications to Chemistry, Physics, Materials Science, Engineering, Biology and Medicine, vol. 1–35. World Scientific Publishing Company, Danvers (2014)Google Scholar
- Milenković, S.M., Zvezdanović, J.B., Anđelković, T.D., Marković, D.Z.: The identification of chlorophyll and its derivatives in the pigment mixtures HPLC-chromatography, visible and mass spectroscopy studies. Adv. Technol. 1(1), 16–24 (2012)Google Scholar
- Smith, K.M.: porphyrins and Metalloporphyrins, p. 124. Elsevier Scientific Publishing, New York (1975)Google Scholar