Diglycol complex

In all three diglycolate complexes the M—0(eq) i.e. metal-ether oxygen, distances are longer than the M—0 (carboxylate) distances 200, 201). This is... 

Table 29. Logarithm of first formation constant and the change of free energy (AGi), enthalpy (AH ) and entropy (AS ) of rare earth diglycolate complexes [409, 410]...

Field TB, Cobum J, McCourt JL, McBrydeWAE (1975) Composition and stability of some metal citrate and diglycolate complexes in aqueous solution. Anal Chim Acta 74 101-106 Wyrzykowski D, Czupryniak J, Ossowski T, Chmurzynski L (2010) Thermodynamic interactions of the alkaline earth metal ions with citric acid. J Therm Anal Calorim 102 149-154 Zelenin OYu. (2007) Interaction of the Ni ion with citric acid in an aqueous solution. Russ J Coord Chem 33 346-350... 

Attachment of carbonyl groups to crowns makes these products more akin structurally to the natural ionophore antibiotics such as valinomycin. The dioxo-derivative (179) of 18-crown-6 was prepared in 35% yield by condensation of tetraethylene glycol and diglycolic acid chloride in benzene at 50 °C for 48 hours (Izatt et al., 1977a and 1977b). This product gives binding constants for Na+, K+ and Ba2+ in methanol which are 102—104 times less stable than for the parent crown - the lower constants are a reflection of less favourable AH values for complexation in these... 

DOT regulations for shipment, 6 301t molecular formula, 6 291t toxicity, 6 302t Allyl complexes of platinum, 19 656 of thorium, 24 773 Allyl diglycol carbonate, molecular formula, 6 305t Allyl ethers, 2 246... 

The tridentate diglycolate hgand, ( 00CCH20CH2C00 ), forms a 1 3 lanthanide complexes 199) in solution. Albertsson 200) was able to isolate the tris-complex as Na3[M(00CCH20CH2C00)3] 2 NaC104-6H20. He found... 

Digermanium hexachloride, synthesis in electric discharge, 6 173, 272 Diglycolic acid, complex formation by, 3 276 Digold heteronuclear cluster compounds. X-ray crystallography, 39 358-362... 

Diglycol amides. TODGA and other diglycol amides displayed an affinity toward Ca(II) and Sr(II) from 2-3 M HN03 solutions (422). Thereby, recovery of not only Ans-Lns but also Sr(II) from spent fuels is contemplated (279, 422, 423). The extracted complexes are represented as [Sr(N03)2L2(HN03)], where L = TODGA. 

In the case of nitriloacetate complexes, the changes in enthalpy have been explained in terms of the consequences of lanthanide contraction (i) increasingly exothermic complexation with decreasing crystal radius and (ii) decreasing exothermic complexation with decreasing hydration of the cation [22]. In the case of dipicolinates and diglycolates these effects become small as the coordination sphere loses water molecules. Thus AH3 and A S3 vary more regularly than A Hi and A Si. 

Fig. 21. The variation of the parameters of complex formation, (AG ), (AHx) and (ASi), for the diglycolate (32) complexes with the L-values of the trivalent lanthanides.

Also, free radieal photoinitiation of polymerization of multifunctional acrylate monomers (trimethylolpropane triacrylate and phthalic diglycol diacrylate) was reported to take place by a cationic cyanine dye-borate eomplex 1,3,3, r,3, 3 —hexamethyl-11 -chloro-10,12-propylene tricarbocyanine friphenyl-butyl borate. The dye-borate complex was illustrated as follows ... 

It is appropriate to consider the relative stability of lanthanide conq)lexes as a first indicator of a ligand s potential applicability for lanthanide separations. In fig. 9 is shown a plot of the relative stability of a variety of lanthanide carboxylate complexes (normalized to log/ (Gd )=0) of importance in ana ical separations. The 1 2 complexes of the lanthanides with glycolate and digjtycolate exhibit similarly poor discrimination of lanthanide ions between Gd and Ho, though the overall slope is greater for diglycolate. The 1 2 lactate complexes vary more regularly than these species, but... 

The most concentrated component in this complex equilibrium is methylene glycol (n = 1) with a formation equilibrium constant, K = 5 X 10 at 60°C. Studies on the NMR spectra of the glycol oligomers and the reaction mechanisms under acidic and basic conditions have been done. In an acidic medium the unique formaldehyde molecule takes the form of a carbonium ion, whereas in a basic medium it reacts through an ionic species generated from the diglycol molecular form. It was shown in an early NMR study by Woodbrey that if other hydroxyl groups are present, like on phenol or methanol, hemiacetals are formed. Raman and infrared spectra and other specific reactions are covered in Meyer and Walker. 

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