Electronic-conformational coupling causes

Here we discuss light absorption by various components of the cell and the effects caused by light absorption. Primary photoinduced cellular effects are produced by light absorption to induce transition between two electronic states (electronic or coupled electronic-vibrational [vibronic] transitions). Purely vibrational transitions (such as IR and Raman) are of significance only in stmctural identification and in conformational analysis. We first discuss the absorption by various constituent molecules and biopolymers. Subsequently we discuss the various photochemical and photophysical processes induced by light absorption. Then we discuss the effects produced from light absorption by an exogenous chromophore added to the cell. 

Interestingly, the sulfur-linked bis-crown ligand [8] shows an unprecedented cathodic potential shift upon addition of K+ cations to the electrochemical solution (Table 3). It is believed to be a conformational process that causes the anomalous shift of the ferrocene/ferrocenium redox couple and not a through-space or through-bond interaction, as these effects would produce the expected anodic potential shift of the ferrocene redox couple. The origin of the effect may be a redirection of the lone pairs of the sulfur donor atoms towards the iron centre upon complexation. This would increase the electron density... 

The conductivity of salts in solvents of low dielectric constant, and of metals in liquid ammonia, exhibit minima which may be explained in terms of an equilibrium between ions and a coulombic compound of two ions, or "ion pairs." This equilibrium conforms to the law of mass action. At limiting conductance in solutions of sodium in liquid ammonia, part of the current is carried by metal ions, but seven-eighths is carried by electrions. Following the BLA model, it is assumed that when two ion pairs, consisting of a sodium ion and an electron, come together, the spins of the two electrons couple to form disodium spinide. Increase in conductivity past the minimum is assumed to be caused by dissociation of disodium spinide into sodium ions and spinions. 

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