Light-induced transients

Schmidt, J.A., Heitner, C., Kelly, G.P., Wilkinson, F.W., "Observation of Light-Induced Transients in Thermomechanical Pulp Using Diffuse-Reflectance Laser-Flash Photolysis". Proceedings of the 1989 International Symposium on Wood and Pulping Chemistry, Raleigh, N.C., 1989. 

Harada, A., Sakai, T., and Okada, K., 2003, Photl and phot2 mediate blue light-induced transient increases in cytosolic Ca2+ differently in Arabidopsis leaves. Proc. Natl. Acad. Sci. USA 100 8583-8588. 

GT Babcock and K Sauer (1975) A rapid, light-induced transient in electron paramagnetic resonance signal II activated upon inhibition of photosynthetic oxygen evolution. Biochim Biophys Acta 376 315-328... 

The thermodynamic driving force (AG) for each of the S-state transitions has been estimated from measurements of the temperature-dependent equilibrium constants for the light-induced transient intermediate states P680+/Yz and Yz /WOC(Mn). These values were then placed on... 

Figure 3.10 Light-induced transient response of MEHPPV- (a, b) and CNPPV-coated (c, d) SWNTs-FET under different gate voltages [-8 V for (a) and (c) -1-8 V for (fo) and (d)]. Reprinted (adapted) with permission from Chawla, J.S. et al.. Semiconducting polymer coated single wall nano tube field-effect transistors discriminate holes from electrons. Applied Physics Letters, 2007. 91(4) p. 043510. Copyright (2007) American Institute of Physics.

Figure 3.10 Light-induced transient response of MEHPPV- (a, b) and CNPPV-coated...

Bennett, N., Michel-Villaz, M., and Dupont, Y., Cyanine dye measurement of a light-induced transient membrane potential associated with the metarhodopsin 11 intermediate in rod-outer-segment membranes, r. /. Biochem., Ill, 105,1980. 

Kothe G, Weber S, BittI R, Ohmes E, Thurnauer M and Norris J 1991 Transient EPR of light-induced radical pairs in plant photosystem I observation of quantum beats Chem. Rhys. Lett. 186 474-80... 

The founding member of the TRP channel family, TRP, was identified as the product of a gene locus, which was referred to a transient receptor potential (TRP), because TRP mutant flies display a defect in light induced Ca2+ influx. 

Alicyclic ew-dialkyldiazenes are very thermolabile when compared to the corresponding tram-isomers, often having only transient existence under typical reaction conditions. It has been proposed49 that the main light-induced reaction of the dialkyldiazenes is tram-cis isomerization. Dissociation to radicals and nitrogen is then a thermal reaction of the cis-isomer (Scheme 3.19),... 

Radical Pair States. - So far we have discussed single radical-ions that occur in the charge-separation process and can be trapped under certain condition in bRC or can even be chemically generated. The initial light-induced charge separation creates radical pairs (RPs) that can be studied by time-resolved transient or pulse EPR ... 

I and II. At very low temperatures a transient form photorhodopsin with a wavelength maximum at 580 nm may precede bathorhodopsin.461b,501-502a Furthermore, nanosecond photolysis of rhodopsin has revealed a blue-shifted intermediate that follows bathorhodopsin within 40 ns and decays into lumirhodopsin.500,503,504 The overall result is the light-induced isomerization of the bound 11-czs-retinal to all-fraus-retinal (Eq. 23-38) and free opsin. Tire free opsin can then combine with a new molecule of 11-czs-retinal to complete the photochemical cycle. 

Stufkens and Hard observed light induced formation of zwitterions and biradicals from the diimine clusters [Os3(CO)io(iPr-AcPy)] and [Os3(CO)io (dmb)] using picosecond UV/vis and nanosecond IR spectroscopies. Picosecond transient spectra indicated generation of the ligand anion radical and evolution over approximately 50 ps to a much longer lived transient that was attributed to an opened cluster with an associated ligand on the diimine metal. Figure 15 shows the proposed evolution of species in the photoreaction [93,94]. 

In a model proposed by Lewis [228] the effect of the excited state of retinal on the conformational state of the protein is considered to be the first step of the excitation mechanism. Charge redistribution in the retinal by excitation with light would have the consequence of vibrationally exciting and perturbing the ground state conformation of the protein, i.e., excited retinal would induce transient charge density assisted bond rearrangements (e.g., proton translocation). Subsequently, retinal would assume such an isomeric and conformational state so as to stabilize maximally the new protein structure established. In this model, 11-m to trans isomerization would not be involved in the primary process, but would serve to provide irreversibility for efficient quantum detection. It was also proposed that either the 9-m-retinal (in isorhodopsin) or the 11-m-retinal (in rhodopsin) could yield the same, common... 

The light-induced dimer should eventually dissociate to return to the monomers, because no permanent change was observed. It may be reasonable to assume that the dimer dissociates when the photoadduct state of LOV2 goes back to the ground state. We should emphasize that this TG technique for the D measurement in the time domain has been the only one technique that can detect such transient dimer formation. 

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