Glycol , reaction with metal complexes

Ethylenediaminetetraacetic acid, analogs, complexes of, 3 277 chelation by, 3 276-277 cobalt complex of, 3 281 complexes, 3 277-278 formation constant of, 3 273-274 -nickel, 3 17-18 stability of, 3 266-267 reaction with metal ions, 3 62 Ethylene dibromide, irradiation of, 5 196 4,5-Ethylenedithio-1,3-dithiole-2-thione based supramolecular complexes, 46 200-204 Ethylene glycol, 32 4... 

The toluene phase contained the reactants and products and the ethylene glycol phase the metal complex and KOAc. The reaction takes place in the ethylene glycol phase and at the interface [Eq. (5)]. In a typical experiment, 0.1 mmol of catalyst was dissolved in 10 mL of ethylene glycol, mixed with a solution of 10 mmol of iodobenzene and 10 mmol of butyl acrylate in 10 mL of toluene. These two phases were then mixed at 140 °C along with 10 mmol KOAc for several hours. Yields of > 99% at 100% selectivity were obtained for the trans compound. 

Reactions. Because it contains both a carboxyl and a primary hydroxyl group, glycolic- acid can react as an acid or an alcohol or both. Thus some of the important reactions it can undergo are esterification, umidation. salt formation, and complexation with metal ions, which lead to many of its uses. As a fairly strong acid it can liberate gases (often toxici when il reacts wilh Ihe corresponding salts. 

In commercial practice, all PET is made using an antimony compound for the final polycondensation stage. The transesterification reaction between DMT and the glycol is catalysed by salts of manganese, zinc, calcium, cobalt, or other metals. At the end of the ester-interchange stage, when essentially all of the methanol has been evolved, the transesterification catalyst is converted to a catalytically inactive and substantially colourless form by reaction with a phosphorus compound such as triphenyl phosphate or phosphite. Polyesters of 1,4-cyclo-hexanedimethanol and DMT or TA are made using complex titanium catalysts. 

Addition of Complexing Agents. Complexation of metallic centers in the precursors by various chelating agents such as acetylacetone, ethylene glycol, and triethanolamine allows the control of the hydrolysis and condensation reactions of the inorganic precursors in the synthesis of metal oxides. Alternately, surfactants with a complexing ability can also be used. 

Macroporous glycidyl methacrylate-ethylene glycol dimethacrylate (GMA-EGDM) copolymer beads were synthesised and characterised for pore volume and surface area. These reactive copolymers were derivatised with 2-picolyl amine and coordinated with chromium and vanadium ions. The peroxocomplexes of these supported metal complexes were generated by the addition of hydrogen peroxide / tertiary butyl hydroperoxide(tert. -BHP) and shown to catalyse a variety of oxidation reactions. 

Although MEEP-metal salt complexes show high ionic conductivities, these materials have undesirable creep properties at ambient temperatures, thus precluding their use in practical devices. To overcome this problem, one approach has been to synthesize dimensionally stable poly(phosphazenes) by crosslinking poly-[(chloro)(methoxy ethoxy ethoxy) phosphazene] with polyethylene glycol). If some of the chlorines in poly(dichlorophosphazene) are left unsubstituted after the initial reaction with the sodium salt of methoxy ethoxy ethanol, these can be reacted further with the difunctional poly(ethylene glycol)to afford crosslinked materials (Eq. 13 and Scheme 14) [204]... 

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