In chlorophyll biosynthesis protochlorophyllide reductase (POR) catalyzes the light-driven reduction of protochlorophyllide (Pchlide) to chlorophyllide, providing a rare opportunity to trap and characterize catalytic intermediates at low temperatures. Moreover, the presence of a chlorophyll-like molecule allows the use of EPR, electron nuclear double resonance, and Stark spectroscopies, previou...

Proton-coupled electron transfer (PCET) is an important mechanism for charge transfer in a wide variety of systems including biology- and materials-oriented venues. We review several areas where the transfer of an electron and proton is tightly coupled and discuss model systems that can provide an experimental basis for a test of PCET theory. In a PCET reaction, the electron and proton may tran...

The electronic absorption spectrum of the homodimeric special pair in bacterial photosynthetic reaction centers is greatly modified when one of the bacteriochlorophylls is replaced by a bacteriopheophytin to form a heterodimer. The absorption exhibits further unusual changes when hydrogen bonds from the protein to conjugated carbonyl groups are added or removed. In order to explain these absorp...

The earliest primary photochemical reaction of green plant photosynthesis has, thus far, remained unexplored as reaction center chlorophyll a (Chl a) complexes have not yet been isolated [l] . In contrast, primary photochemical steps have been successfully studied, with picosecond (ps) absorption spectroscopy [2,3] in isolated bacteriochlorophyll (B Chl)-reaction center complexes from photosynt...

In this study interaction of phenothiazine sulfur dye with (5, 5) armchair open-end boron nitride nanotubes (BNNTs) in interaction (with a length of 7 Å) was investigated. The impacts of the estereoelectronic effect associated with donor-acceptor electron delocalizations, dipole-dipole interactions and total steric exchange energies on the structural and electronic properties and reactivity of ...

in this paper, the effect of surface area of reaction layers in gas diffusion electrodes on oxygen reduction reaction was investigated. for this purpose, various amounts (0.1, 0.2, 0.3, 0.4, 0.5, 1, 1.5 and zero %wt of total loading of reaction layer) of single walled carbon nanotube (swcnt) were inserted in the reaction layer. the performance of gas diffusion electrodes for oxygen reduction re...

The reaction of single-component molecular crystal nanorods with a second species to form cocrystal nanorods is described. Single-component crystalline nanorods, composed of 9-methylanthracene (9-MA), are grown in a porous anodic aluminum oxide template. These templated rods are then exposed to a suspension of 1,2,4,5-tetracyanobenzene (TCNB) in water, which slowly diffuses into the 9-MA rods o...

Vectorial charge transfer and a molecular recognition at the interface between two dielectric media are important stages in many bioelectrochemical processes such as those mediated by energy-transducing membranes [1–4]. Many biochemical redox reactions take place at aqueous medium/membrane interfaces and some of them are multielectron processes. About 90% of the oxygen consumed on Earth is redu...