Ethylene glycol conformations

Nam, S., Parikh, D.V., Condon, B.D., Zhao, Q., Yoshioka-Tarver, M., 2011. Importance of poly(ethylene glycol) conformation for the synthesis of silver nanoparticles in aqueous solution. J. Nanopart. Res. 13, 3755—3764. 

Figure 9.4. Ethylene glycol conformations. (From Lii and Allinger. Copyright 2008 by the American Chemical Society. Reprinted by permission from the American Chemical Society.)...

Harder P, Grunze M, Dahint R, Whitesides G M and Laibinis P E 1998 Molecular conformation in oligo(ethylene glycol)-terminated self-assembled monolayers on gold and silver surfaces determines their ability to resist protein adsorption J. Rhys. Chem. B 102 426-36... 

Flame-Retardant Resins. Flame-retardant resins are formulated to conform to fire safety specifications developed for constmction as well as marine and electrical appHcations. Resins produced from halogenated intermediates (Table 5) are usually processed at lower temperatures (180°C) to prevent excessive discoloration. Dibromoneopentyl glycol [3296-90-0] (DBNPG) also requires glass-lined equipment due to its corrosive nature. Tetrabromophthahc anhydride (TBPA) and chlorendic anhydride (8) are formulated with ethylene glycols to maximize fiame-retardant properties reaction cycle times are about 12 h. Resins are also produced commercially by the in situ bromination of polyester resins derived from tetrahydrophthahc anhydride... 

Vicinal hydroxyl groups, as in an ethylene glycol unit, have conformational attributes that can be described by using acyclic orientational notation... 

In order to work out in more detail Harada and coworkers took a step further by preparing fluorescence-labeled bis(l-naphthylacetyl)-PEG (PEG-1N2) and bis(2-naphthylacetyl)-PEG (PEG-2N2). The complexes of these compounds with y-CD were isolated by standard methods and subjected to NMR measurement. The results also conformed to the conclusion that four ethylene glycol units are included in one y-CD. 

Follow the recommendations of your vehicle manufacturer concerning engine coolants and be certain the product you select conforms to standard specifications for engine coolant such as ASTM Specification for Ethylene Glycol Base Engine Coolant (D 3306). Any high quality engine coolant must pass the requirements of this specification. 

The conformation of ethylene glycol occluded in high silica sodalite has been determined [25]. In the category of zeolite-hydrocarbon complexes, we have seen completion of studies at relatively low loading levels of benzene in zeolites L [26,27] and Na-Y [28]. Benzene has also been studied in... 

Experimental Systems. Experimentally, amphiphUic Frechet-type poly(aryl ether) dendrimers displaying poly(ethylene glycol) (PEG) peripheral arms were shown to form monomolecular micellar structures exhibiting solvent-sensitive conformational changes (Fig. 11.7 Gitsov and Frechet 1996). 

Figure 11.7 Solvent-sensitive conformational changes of Frechet-type polyfaryl ether) dendrimers with poly(ethylene glycol) termini.

Kampf JP, Frank CW, Malmstroem EE, Hawker CJ. Stability and molecular conformation of poly(benzyl ether) monodendrons with oligo(ethylene glycol) tails at the air-water interface. Langmuir 1999 15 227-233. 

The contribution of the poly(Pro)II conformation to the ensemble of unordered peptides has been considered.1158 The temperature dependence of [0]222 for the peptide Ac-YEAAAKEAPAKEAAAKA-NH2 in 8 M guanidinium chloride and of poly(Lys) in water and in ethylene glycol/water (2 1) mixtures 156 was fitted to a two-state equation for a poly(Pro)II-unordered equilibrium with a temperature-independent AH and temperature-independent molar ellipticities for the two components. The peptide with a Pro at the central position is an unordered peptide, the spectrum of which has pronounced poly(Pro)II-like features at low temperatures. This fit yielded [0]222=- -9580 deg-cm2dmol 1 for the poly (Pro)II component and —5560 deg-cm2-dmol 1 for the unordered component. These values provide a method for roughly estimating the poly(Pro)II content, /Pn, of an unordered peptide from [0]222 ... 

The nucleation of parallel (3-sheet structure via metal ion chelation in aqueous solution was investigated by incorporating an ethylene glycol spacer between a dibenzofuran-4,6-dipro-panoic acid template and the two peptide strands (Scheme 6).[7 The flexibility of the ethylene glycol spacer allows the peptide to sample a variety of largely unordered conformations in the absence of metal ions. Upon binding of palladium(II), nickel(II), or copper(II) ions, the peptidomimetic adopts a well-defined (3-sheet conformation as discerned from biophysical and spectroscopic studies (i.e., CD, IR absorption, and H NMR spectrometry).17 The synthesis of the dibenzofuran-4,6-dipropanoic acid template was discussed... 

Gotoh, Y., Tsukada, M., and Minoura, N. (1993) Chemical modification of silk fibroin with cyanuric chloride-activated poly (ethylene glycol Analysis of reaction site by 1H-NMR spectroscopy and conformation of the conjugates. Bioconjugate Chem. 4,554—559. 

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