Sorbates, groupings

Carboxylic Acid Group. Sorbic acid undergoes the normal acid reactions forming salts, esters, amides, and acid chlorides. Industrially, the most important compound is the potassium salt because of stabiUty and high water solubiUty. Sodium sorbate [7757-81-5] (E,E form [42788-83-0]) is less stable and not commercially available. The calcium salt [7492-55-9] which has limited solubiUty, has use in packaging (qv) materials. 

The criteria for choosing inhibitors in this study were the ability to compete with diethanolamine for the nitrite and lack of toxicity. An attempt was made to cover as broad a group as possible within the limits of feasibility. Ascorbic acid in its water soluble form and its oil soluble form, the palmitate, represent the enediols, Sorbate is a diene fatty acid which has been shown to inhibit nitrosation (10), Since the pK of sorbic acid is 4,76, at the pH of these experiments, both water soluble sorbate ion and oil soluble sorbic acid are present in significant amounts. Sodium bisulfite is a strong inorganic reducing agent which has an acceptable lack of toxicity at the concentration... 

For the understanding of the binding of heavy metals on clays one needs to consider - in addition to ion exchange - the surface complex formation on end-standing functional OH-groups. Furthermore, the speciation of the sorbate ion (free hydroxo complex, carbonato- or organic complex) and its pH-dependence has to be known. 

Adsorption to surface groups capable of forming inner sphere bond with sorbate... 

Methyl sorbate and analogous monomers were polymerized in the presence of (/ )-2-methylbutyllithium or of complexes between butyllithium and optically active Lewis bases (329, 330) (see formulas 32 and 33) the polymers show weak optical activity. The prevailing configuration of the — CH(CH3)— group was determined by the sign of rotation of the methylsuccinic acid obtained from the polymer after ozonization. The low optical purity ( = 6%) found is related to the presence of a remarkable stereochemical disorder (115, 116) and to the fact that the chiral agent is active, at least in the case of methylbutyllithium, only in the initiation reaction. 

R and R groups and an all-trans arrangement of the double bonds. The polymer is named transerythrodiisotactic 1,4-poly (methyl sorbate) or diisotactic poly[eryr/tro-3-(methoxycar-bonyl)-4- -methylbut-1 -ene-1,4-diyl]. 

Later, Tieke reported the UV- and y-irradiation polymerization of butadiene derivatives crystallized in perovskite-type layer structures [21,22]. He reported the solid-state polymerization of butadienes containing aminomethyl groups as pendant substituents that form layered perovskite halide salts to yield erythro-diisotactic 1,4-trans polymers. Interestingly, Tieke and his coworker determined the crystal structure of the polymerized compounds of some derivatives by X-ray diffraction [23,24]. From comparative X-ray studies of monomeric and polymeric crystals, a contraction of the lattice constant parallel to the polymer chain direction by approximately 8% is evident. Both the carboxylic acid and aminomethyl substituent groups are in an isotactic arrangement, resulting in diisotactic polymer chains. He also referred to the y-radiation polymerization of molecular crystals of the sorbic acid derivatives with a long alkyl chain as the N-substituent [25]. More recently, Schlitter and Beck reported the solid-state polymerization of lithium sorbate [26]. However, the details of topochemical polymerization of 1,3-diene monomers were not revealed until very recently. 

Fig. 11 a Side view of an anion layer sandwiched between cation layers viewed down along the crystallographic n-axis. b CH/n interactions between the aromatic groups in the ammonium cation layers for 1-naphthylmethylammonium ( , )-sorbate [82]... 

Sorbates (solute molecules) may be grouped according to their intermolecular interactions. These groupings are based on electronic configurations, electron density, and functional groups in the molecule. 

Asymmetric induction to main-chain chiral centers can also be achieved by the radical polymerization of sorbates having chiral ester groups [80,81] and 1,3-butadiene-l-carboxylic acid complexed with optically active amines [82,83]. 

For more complex molecules a reasonable estimate of the heat of sorption can sometimes be made by considering group contributions. Such an approach works best for nonpolar sorbates on nonpolar surfaces but is subject to considerable error for polar systems in which the electrostatic energies of adsorption are large. 

Table I gives a summary of interaction energies for a number of sorbate-sorbent pairs. Here groupings are made for the theoretical nonelectrostatic (

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