Bond state probability

The state of the oxygen molecule, 1.62 v. e. above the normal state, probably corresponds to a double bond between the two atoms. This gives 3.47 v. e. for 0 0. 

The probability for a conformation of an unperturbed chain of n C-C bonds on the underlying diamond lattice can be expressed in terms of the probability for state r) at the second bond and the conditional probability for state 7] at bond i (2 < i < n), given state at the preceding bond. These probabilities, which are usually denoted by p,/ 2 and q , respectively, are extracted from 2 of Eq. (4.1) using the conventional partial derivatives [35,36]. Then the probability, p, for a specified conformation of the entire chain is ... 

Therefore, the total probability of locating an electron in the bonding state... 

A priori rotations state probabilities averaged over all internal bonds... 

These results clearly show that the stereoselectivity in the photocycloaddition of 1-CN and 2-CN with 2- and/or 3-furylmethanol is reasonably explained by the hydrogen-bonding in the excited states. Probably, a partial electron transfer from furylmethanols (F-OH) to the excited singlet states of cyanonaph-thalenes (ArCN) contributes the formation of polar exciplexes [ArCN8 F-OH8+], where ArCN8 interacts with more acidic OH group of F-OH8 to produce hydrogen bonds in the excited states. 

In contrast to the usual blending of cellulose via a solution medium, a fine-powdered composition was obtained by ball-milling a dry mixture of fibrous cellulose and granulated PEG without any solvent [63]. A certain extent of compatibilization of PEG with cellulose appears to occur even in their solid state, probably by insertion of parts of PEG molecules into the cellulose domains, followed by the formation of hydrogen bonds between cellulose hydroxyls and polyether oxygens. It was shown that such a mechano-chemically prepared powder was moldable three-dimensionally by facile hot-press treatment, e.g., at 120 °C for a composition of CELL/PEG = 80/20 (wt/wt) [64],... 

It follows from these similarities in solvent properties that equilibrium or rate constants of reactions in which the solvent molecules do not directly participate generally show comparatively small changes when the deuterium content of the medium is altered. This is true even for rates of proton transfer between neutral substrates and acetate ions, which as a rule are reduced by 20-40% on going from H20 to D20 (Bell, 1965). Because of the anionic nature of one of the reactants and of the transition state these reactions are of a type in which solvent-solute interactions through hydrogen bonds are probably particularly large, and yet the solvent isotope effect is fairly small. Reactions in... 

Free radicals, formed by homolytic bond cleavage, may couple to groups on a receptor in several ways (Fig. 2.4A). Diradicals (e.g. triplet excited states) probably abstract an atom from the receptor (e.g. H ) and the two radicals that are formed couple (Fig. 2.4b). 

The photodissociation process takes place most frequently at excitation of the molecule to a non-bonded state, with subsequent dissociation into products. Since the angular part of the transition probability, according to Chapter 2, is still dependent on the mutual orientation of the E-vector of the initiating light beam and on the transition dipole moment d, one may expect spatial anisotropy of angular momenta distribution both in the dissociation products and in the set of molecules which remains undestroyed. 

The probability of angular distribution of photofragments has the same origin as the probability G(0, (p) in (2.8), but now it is a transition from a bonded state into a non-bonded one. 

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