Solvent, inert ionizable

When the solvent is inert it is merely a diluent and the neutralization product is obtained directly. When the solvent is ionizable,... 

It needs to be pointed out, that the investigation of some technically important polymers like polyolefines has not been very successful so far. Owing to their inert nature they are difficult to dissolve and also difficult to ionize. Typically one needs for the ionization process some heterogeneities or double bonds in the polymer. For some insoluble substances a solvent-free sample preparation method has been developed that allows a characterization by MALDI-TOF mass spectrometry [93]. 

The extent of the ionization produced by a Lewis acid is dependent on the nature of the more inert solvent component as well as on the Lewis acid. A trityl bromide-stannic bromide complex of one to one stoichiometry exists in the form of orange-red crystals, obviously ionic. But as is. always the case with crystalline substances, lattice energy is a very important factor in determining the stability and no quantitative predictions can be made about the behaviour of the same substance in solution. Thus the trityl bromide-stannic bromide system dilute in benzene solution seems to consist largely of free trityl bromide, free stannic bromide, and only a small amount of ion pairs.187 There is not even any very considerable fraction of covalent tfityl bromide-stannic bromide complex in solution. The extent of ion pair and ion formation roughly parallels the dielectric constant of the solvents used (Table V). The more polar solvent either provides a... 

In organic chemistry this stabilizing effect is well known the stability of carbanions is known to be enhanced by nitro groups. The stability of the cyclopentadienide anion is increased by complexing with a typical Lewis acid so that it becomes less reactive. For example, ferrocene is not ionized in nitromethane solution. Addition of a Lewis acid such as aluminum chloride facilitates the occurrence of intramolecular race-mization (75) a process which is believed to involve ionic intermediates [16). This belief is supported by kinetic evidence and the failure of the reaction to occur in nearly inert solvents like methylene chloride and in those of high donidty. Whereas the former do not support the solvation of the cation formed in the process of ionization, the latter will react preferentially with the Lewis acid, which is then no longer available for the stabilization of the carbanion. 

Polyelectrolytes are most commonly studied as solutions in aqueous media as a consequence of their poor solubility in organic solvents. In order to minimize the effects of ionization in an aqueous media, evaluation of [77] is done in an aqueous solution of an inert 1 1 electrolyte as the solvent. In such solvents, poly electrolytes behave as if they were neutral polymers [32-34],... 

The salt is formed by hydrogen bonding and is usually in a polymer state (BHA) . The bond between BH and A is ionized to various degrees, from lion-ionized (BH...A) to completely ionized (BH+...A ) . The ionization becomes more pronounced with increasing acid-base interactions. When acid HA forms a dimer (HA)2 in the inert solvent, as in the case of carboxylic acids in benzene, the salts denoted by B(HA)2 [(BH+...AT..HA), (AH...B...HA), etc.] are formed. 

The white crystalline solids are readily soluble in organic solvents (even alkanes) but are insoluble in water and the lower alcohols. They are inert to water but are hydrolyzed by dilute acid. In solution they are monomeric and non-ionized. An X-ray crystallographic study of Be40(0Ac)6 shows the O to be centrally coordinated to four Be atoms in a tetrahedral geometry each of the Be atoms is tetrahedrally surrounded by four O donors from bridging acetates and the central oxygen (62).322... 

In the reaction with acetic anhydride in an inert solvent, pyrrole gives a mixture of 1- and 2-acetyl derivatives.139 The substitution at the 2-carbon seems to involve the neutral molecule of pyrrole, whereas that at nitrogen probably involves the dissociated anion. In fact, the C/N isomer ratio is decreased by adding sodium acetate (which favors ionization) and increased by adding acetic acid (which opposes it). 

Heat and titration with acid can accomplish the required H bond ruptures. Cavalieri and Rosenberg (358) have described this process, and they illustrate how it relates to the Watson and Crick structure for nucleic acids. They show further that the temperature required in an H bonding solvent is lower than in inert solvent, consequently these two factors can work in the same direction. Denaturation may also occur by ionization of amino groups (23), and the effect of radiation on DNA has been imputed to breaking of H bonds (454, 2147a). Mechanical stress may be able to break H bonds and denature proteins (1105). 

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