Alkali metal phenolates

The magnetic properties of Cj and C4 ring atoms are most affected by ion pairing. The calculated 5( C) chemical shifts in ppm [obtained from GIAO-HF/6-311+G(d,p) calculations] in PhO—M vary as follows  

Deshielding of the atom C4 in the ion-paired structures is thus obvious. The chemical shifts of other carbon atoms remain almost unchanged upon deprotonation or ion pairing. 

FIGURE 26. Selected B3LYP/6-311++G(d,p) optimized bond lengths (A) of some alkali metal phenolates in their ground singlet state 

The NICS(O) values of the alkali phenolates increase down the group from —9.9 in Li, —9.2 in Na, —8.8 in K, —8.0 in Rb, —7.5 in Cs and —6.3 for free phenolate anion. Thus the charge localization is still effective for cesium phenolate, which has a more aromatic character than the free anion. The other criteria yield a similar pattern. The loss of aromaticity in the free phenolate anion, 60% of the neutral phenol, due to a p-jr delocalization discussed above, could largely be restored by ion pair formation with alkali metal cations, thanks to a charge localization effect of the latter. 

---

Amongst the catalysts used or the polymerisation-trimerisation reactions are alkali metal phenolates, alcoholates and carboxylates and compounds containing o-(dimethylaminomethyl)phenol subgroups. Fluorocarbons such as trichloro-fluoromethanes are used as the sole blowing agents in the absence of any isocyanate-water reaction. 

Yamaguchi, T. Sato, K. Catalytic carboxylation process for producing aromatic hydroxycarboxylic acids from alkali metal phenolates and carbon dioxide. U.S. Pat. Appl. Publ. US 2006122420, 2006 Chem. Abstr. 2006,145, 27722. 

The reactions of nitroarenes with anionic nucleophiles in liquid ammonia have been reviewed. This report includes the reactions of alkali metal phenolates, and it is... 

PMDIs are less reactive than monomeric diisocyanate but are also less volatile. Tbe polyisocyanurate produced from tbis material will be of type shown in Figure 1.33b. Some of the catalysts used for the polytrimerization reactions are alkali-metal phenolates, alcoholates and carboxylates, and compounds containing o-(dimetbylaminomethyl)-phenol groups. 

Eor alkali metal compounds used as initiators, the active species of polymerization was shown to be an alkali metal alcoholate for the aliphatic cyclic carbonates [24] and an alkali metal phenolate for the aromatic cyclic carbonates [29]. The time required to shift from kinetic control to thermodynamic control is about a few minutes when the polymerization of aliphatic cyclic carbonates is performed at 25 °C in toluene solution. The larger the alkali-metal counterion, the faster the polymerization and the smaller the selectivity parameter, = kp/kb-... 

Alkyl hydroperoxides can be Hquids or soHds. Those having low molecular weight are soluble in water and are explosive in the pure state. As the molecular weight increases, ie, as the active oxygen content is reduced, water solubiUty and the violence of decomposition decrease. Alkyl hydroperoxides are stronger acids than the corresponding alcohols and have acidities similar to those of phenols, Alkyl hydroperoxides can be purified through their alkali metal salts (28). 

The chemical resistance of PCTFE is good but not as good as that of PTFE. Under certain circumstances substances such as chlorosulphonic acid, molten caustic alkalis and molten alkali metal will adversely affect the material. Alcohols, acids, phenols and aliphatic hydrocarbons have little effect but certain aromatic hydrocarbons, esters, halogenated hydrocarbons and ethers may cause swelling at elevated temperatures. 

One would think that thermal destruction of polyethylene should be inhibited by hydroxides of alkali metals according to the following scheme, as with phenols ... 

The methoxymethyl (MOM) and (3-methoxyethoxymethyl (MEM) groups are used to protect alcohols and phenols as formaldehyde acetals. These groups are normally introduced by reaction of an alkali metal salt of the alcohol with methoxymethyl chloride or (3-methoxyethoxymethyl chloride.157... 

Interaction of lead oxide with bromide salts in phenol at the ratio Br PbO less than 2 yields the precipitation of white sediments with the general formula PbnOm(OPh)(2.z)(n-m)Brz(n-m), where n = 4 - 10, m = 1 - 4, z = 0 - 1 and formation of (n-m) moles of water. Reaction takes place in the presence of a variety of bromide salts including quaternary and alkali metal bromides. In the latter case, the presence of acoordinating solvent, e.g. MeCN, is necessary. The composition of product lead bromophenoxides depends on the Br PbO ratio, bromide salt and solvent. These complexes usually have Pb 0 ratio of 4 1 or 3 1, and variable levels of bromide (including some bromide-free complexes) (Table 3). 

In all cases, dithio-phosphorus acids can be liberated from their alkali-metal salts by reacting them with acids such as HC1. Thio-ester derivatives of the dithio-phosphorus acids can be synthesised via reaction of the acids themselves with an alcohol or phenol (Equation 26) or from reaction of their alkali-metal salt with an alkyl halide (Equation 27). 

Sulphonic esters have been obtained from the sulphonyl chlorides in high yields under mild conditions for a range of alcohols and phenols [e.g. 18, 19]. Of particular value is the protection of glycosides possessing a free hydroxyl group and hydroxy-steroids, which are tosylated readily under phase-transfer conditions [20-22]. Alkyl sulphinites have been obtained in a similar manner [23]. Alternatively, preformed tetra-rt-butylammonium sulphonates or their alkali metal salts have also been alkylated with haloalkanes or alkyl fluorosulphonates [24,25]. In contrast with more classical procedures, tosylation of alcohols, which are susceptible to E/Z-isomerism, e.g. Z-alk-2-en-l-ols, occurs with retention of their stereochemistry under phase-transfer catalysis [26]. 

Pentachloropyridine undergoes a regio-selective dechlorination to give 2,3,5,6-tetrachloropyridine [118]. The reduction of 1- and 2-phenoxynaphthalene at the cathode or by an alkali metal afforded phenol and naphthalene. The intermediacy of the naphthalene radical has been made probable by the use of an internal radical trap [119]. 5-Aryloxy-l-phenyltetrazoles cleave reductively predominantly at the tetrazolyl-O bond. The relative rates of... 

Nitrosation of phenolic substrates usually uses nitrous acid prepared in situ from a dilute mineral acid and an alkali metal nitrite. In general, for every phenolic group present in a substrate an equal number of nitroso groups can be introduced into the aromatic ring phenol, resorcinol and phloroglucinol react with nitrous acid to form 4-nitrosophenol, 2,4-dinitrosoresorcinol and 2,4,6-trinitrosophloroglucinol respectively. 

Current Methods. The general outline of the Kolbe-Schmitt reaction, as it is employed in the 1990s, is as follows. In the first step, phenol and hot aqueous caustic are mixed to produce the sodium phenate which is taken to dryness. Next, the phenate and dry carbon dioxide are introduced into the carbonator. Air is excluded to minimize oxidation and the formation of colored compounds. The gas—solid mixture is agitated and heated, first at low temperature, followed by several hours at higher temperatures, to complete the formation of sodium salicylate. Variations of this reaction have been noted in the literature and are still being investigated (10,11). One reported scheme produces salicylic acid or substituted salicylic acids by reaction of a granulated alkali metal salt of the respective phenolic compound with C02 in a fluidized bed at 20—130°C until at least 50—80% of the metal salt has been converted to... 

---