2,2 -Bisphenol metal complexes

Bismuth ligands, 2,989-1061 bonding, 2,1030-1041 7i bonding, 2, 1033-1039 trigonal bipyramidal complexes, 2,1036 Bismuth line, 3,294 Bismuthotungstates, 3, 1042 Bismuth pentafluoride, 3, 292 Bismuth tribromide, 3, 291 Bismuth trichloride, 3, 290 Bismuth trifiuoride, 3, 290 Bismuth triiodide, 3,292 Bismuth trioxide, 3,284 2,2 -Bisphenol metal complexes color photography, 6,109 Bis(trimethylene)triamine metal complexes, 2, 49 4,4 -Bi-l, 2,4-triazolyl metal complexes, 2, 89 polymers... 

Bipyridyl, 4-methyl-4 -vinyl-electrochemical polymerization, 25 electropolymerization, 16 2,2 -Bisphenol metal complexes color photography, 109 Blastocladiella emersonii cation transport, 559 sporulation... 

The synthesis of the 2,4-bisphenol derivative of the standard tetradentate ligand 14 is quite tedious and so far has not been optimized (204). Apart from the fact that the noninnocent phenolate donors may lead to interesting ligand systems and metal complexes, it is the six-membered chelate rings involving the in-plane phenolate donors that lead to structural properties quite different from those of the other bispidine ligands [shown in Fig. 2(e) is a plot of a preliminary X-ray molecular structure of one of the possible conformers (meso form) of a copper(II) complex]. 

Synthesis of the polymeric Schiffbase complexes 4 (see Eq. 6-3) A mixture of the diglycidyl ether of bisphenol A, a metal complex and tetrabutylammon-ium hydroxide was degassed under vacuum and then cast into a mold and cured by heating in a hot-air oven. The completeness of curing was confirmed by the disappearance of the epoxy group absorption at 917 cm in IR spectra. With a molar ratio of metal complex bisphenol A derivative tetra-butylammonium hydroxide = 1 6 0.2 the curing was carried out at 160 °C for 4 h. 

Amgoune A, Thomas CM, Roisnel T, Carpentier JF. 2006. Ring-Opening Polymerization of Lactide with Group 3 Metal Complexes Supported by Dianionic Alkoxy-Amino-Bisphenolate Ligands Combining High Activity, Productivity, and Selectivity. Chem Eur J 12 169-179. 

As stated above, the carbonylation oxidative polycondensation of bisphenol in the presence of transition metal-based catalysts leads to aromatic polycarbonate [scheme (18)] [6]. The reaction of bisphenol (HOArOH, e.g. Ar = p-C6H4 CMe2—C6H4—), carried out under CO and O2 pressure in a chlorohydrocarbon solvent under anhydrous conditions, using a group 8 metal-based catalyst (e.g. a PdBr2 complex) and a redox catalyst (e.g. Mn(II) (benzoinoxime)2, L vMn) in the presence of a base (e.g. 2,2,6,6,N-pentamethylpiperidine, R3N), involves most probably the pathway shown schematically below ... 

Crown ethers were the first artificial host molecules discovered. They were accidentally found as a byproduct of an organic reaction. When Pedersen synthesized bisphenol, contaminations from impurities led to the production of a small amount of a cyclic hexaether (Fig. 2.1). This cychc compound increased the solubihty of potassium permanganate in benzene or chloroform. The solubility of this cyclic compound in methanol was enhanced in the presence of sodiiun ion. Based on the observed phenomena, Pedersen proposed that a complex structure was formed where the metal ion was trapped in a cavity created by the cychc ether. At that time, it was already known that naturally occurring ionophores such as valinomycin incorporated specific metal ions to form stable complexes because of this, compounds able to selectively include metal ions were the source of much attention from researchers. Pedersen called the cychc compound a crown ether, because the cychc host wears the ion guest like a crown. 

The systems are color-stable, weather resistant, flexible, and also adhere well to tin-free and low-tin sheet metals, as used in the manufacture of beverage and aerosol cans. Although arene-ferrocenium complexes even allow the cure of bisphenol A epoxy resins, provided postcuring takes place, these systems have not yet become important in surface protection applications. The reasons for this are inadequate color stability and weather resistance as well as the intense color of these films. 

On the other side, a totally insoluble cross-linked Schiff-base complex was prepared as follows. The glycidyl ether of bisphenol A was reacted with a Schiff-base chelate (prepared from 2,4-dihydroxybenzaldehyde and 1,3-diaminopropane followed by metallation) in a molar ratio of, for example, 6 1 at 150-200 °C to obtain the polymer 4 as shown in Eq. 6-3 (see Experiment 6-1, Section 6.6) [19]. Polymeric copper complexes in particular exhibit good thermal stabilities and good mechanical properties such as tensile strength. 

Polysulfones are a family of engineering thermoplastics that exhibit excellent high-temperature properties. Many variations of this material have a continuous use temperature of 150 C and a maximum temperature of around 170 C. Polysulfones are produced by the Friedel-Crafts reaction of sulfonyl chloride groups with aromatic nuclei, or by reacting 4,4 -dichlorodiphenylsulfone with alkali salt of bisphenol A. The latter polycondensation is conducted in highly polar solvents, such as dimethylsulfoxide or sulfolane. These materials can be injection molded into complex shapes and can compete with many metals. The following is the chemical structure ... 

In order to prepare advanced molecules of poly(arylene ether sulfones) for fuel cell apphcations without sacrificing their excellent physical properties, Noshay and Robeson developed a mild sulfonation procedure for the commercially available bisphenol-A-based poly(ether sulfone) [62,63]. The sulfonation agents that have been used for this polymer modification are chlorosulfonic acid and a sulfur trioxide-triethyl phosphate complex. Recently, Kerres and co-workers [102] reported an alternative sulfonation process of commercial polysulfone based on a series of steps, including metalation-sulfmation-oxidation reactions. 

Since it is well known that stability of a complex between a crown ether and an alkali metal cation greatly depends on the size of the inner cavity of the former and of the latter and that of all the alkali metal ions dibenzo-18-crown-6 forms the most stable complex with K" ",27 it was interesting to see whether these facts in a parallel way influence the present polymerization reactions. We conducted a series of pol3nnerizations under the same condition as described in "Synthetic Reactions", using various alkali hydroxides (LiOH, NaOH, KOH, and CsOH) the results are tabulated in Table 2. The results strongly imply that phase transfer of the nucleophiles, bisphenolate anions, from the aqueous to the nitrobenzene phase was most efficient when the metal ion was K. This, in turn, indicates that the crown ether-K" " complex is the most stable among the complexes expected to be formed with the alkali metals examined, as has been amply demonstrated by others. For example, Pedersen ... 

The oxidative polymerization of 2,6-dimethylphenol (invented by Hay et al. [91], see also Chap. 8) and the polymerization of potassium 4-bromo-2,6-dim-ethylphenoxide (see Formula 16.6) have both the character of CCPs. The former CCP needs oxygen as reaction partner and a Cu amine complex as catalyst. Heitz et al. [92] observed that contrary to a normal polycondensation high oligomers were formed at low conversions, and he formulated a speculative radical-cation mechanism. The CCP of 4-bromophenoxide salts needs Cu " or other oxidizing metal ions as reaction partners and also involves a radical-cation mechanism [93]. When 4-methyl- or 4-tert.butylphenol are added as initiators, linear chains having one OH end group are formed, whereas addition of tetramethyl bisphenol yields telechelic polyethers (see Formula 15.6). 

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