Polyoxyethylene substituent

Figure 13.27 (Top) Luminescence images of HeLa cells loaded with different concentrations of [Eu2(L62)3] in RPMI-1640 for 7h at 37°C. (Lex = 330nm, Xem >585nm, exposure time 60s). (Middle) Images of HeLa cells loaded with 250 p.M [Eu2(L62)3] (5h at 37°C, exposure time 10 s), then incubated with 40mgmL acridine orange (Xex = 450 90 nm Xem = 515-565 nm, exposure time 10 ms) in PBS (5 min at room temperature). (Bottom) Co-localization experiments cells loaded with 250 p.M [Eu2(L62)3] and 15 mgmL BIODIPY PL LDL (0.5 h, Xex = 470 nm, 2 s exposure time) [77]. (Reproduced from E. Deiters et al., Effect of the length of polyoxyethylene substituents on luminescent bimetallic lanthanide bioprobes, New Journal of Chemistry, 32, 1140-1152, 2008, by permission of The Royal Society of Chemistry (RSC) for the Centre National de la Recherche Scientifique (CNRS) and the RSC.)...

This s)mthetic path has been slightly modified to develop water-soluble homobimetallic helicates for bioanalyses which bear short polyoxyethylene substituents either on (N)l-position of the benzimidazole moiety or on the 4-position of the pyridine rings (Figure 44). 

As already reported in Table 6, the solubility of phosphazene polymers is strongly influenced by the nature of the substituent groups attached at the phosphorus atoms along the -P=N- skeleton. Water-solubility, for instance, can be induced in polyphosphazenes by using strongly polar substituents (e.g. methylamine [84], glucosyl [495], glyceryl [496], polyoxyethylene mono-methylether [273] or sulfonic acid [497,498] derivatives), or may be promoted by acids or bases when basic (amino substituents like ethylamine [499]) or acid (e.g. aryloxy carboxylate [499] or aryloxy hydroxylate [295]) substituents are exploited. 

ID and 2D 13C NMR were carried out in a series of novel nematogens by Bayle and co-workers to study the effects on the conformation and order due to the addition of lateral and/or terminal substituents.249 251 For example, lateral flexible substituents are found to adopt a mean conformation more or less parallel to the mesogenic core. As a result, lateral chains are less disordered than terminal chains. Nematogens containing polyoxyethylene ether (POE) chain as a lateral crown ether and terminal chain(s) have been... 

Materials that are solubilized in polyethylene glycol can be solubilized in the polyoxyethylene chains on the surface of a nonionic micelle. Ismail, Gouda, and Motawi found that the micellar partition coefficients of barbiturates in polysorbates 20, 40, 60, and 80 is a function of the solute substituents and is proportional to the octanol-water partition coefficient of the barbiturate. Similarly, Ikeda, Kato, and Tukamoto showed that the solubilization of alkyl barbiturates by polyoxyethylene lauryl ether is not dependent upon the number of carbons in the substituents. Since the different polysorbates contain different aliphatic groups, the rather small dependence of solubilization upon polysorbate number (i.e., upon alkyl chain length) suggests that the barbiturates are not solubilized primarily in the hydrocarbon portion of the micelle. Gouda, Ismail, and Motawi showed that the solubilization of barbiturates in polyoxyethylene stearates is proportional to the number of polyoxyethylene units in the surfactant. 

Ethomids A series of non-ionic surface active agents. The Ethomids are N-substituted fatty acid amides, the substituents being polyoxyethylene groups. In the Etho-mid C series the fatty acids are from coconut oil, in the Ethomid RT series from hydrogenated tallow in the Etho-mid RO series from red oil. 

With sufficiently long polyoxyethylene chains containing terminal electron-releasing substituents, particularly stable complexes can be formed with alkaline or alkaline earth cations, which are completely wrapped up by the chains, as shown by X-ray analysis... 

Pommier and Guichon have studied the retention of ferrocene derivatives on various stationary phases. The retention was shown to be made up of contributions from the ferrocene moity and from each of the substituents. The logarithms of these contributions are additive, provided that there is no interaction between the substituents or with the cyclopentadienyl rings, e.g. with methyl- and 1,3-dialkylferrocenes. These workers tabulate retention data for separations on SE-30, Apiezon L and polyoxyethylene glycol. 

The importance of a consideration of both solubilizate and solubilizer structure in the selection of a particular surfactant for the solubilization of a given solute is illustrated by studies of the solubilization of para-substituted acetanilides by a series of structurally related poloxamer (polyoxyethylene-polypropylene) ABA block co-polymers (Pluronic surfactants) [83]. Fig. 5.19 shows the relation between the n value for the p-substituent group of the acetanilides and the slope K of plots of the amount of drug solubilized per... 

Chiral crown ether selectors are derivatized forms of polyoxyethylene crown-6 [27]. This crown ether has a cavity that exactly match the size of an ionized primary amine group, -NHs". The host-guest ammonium-crown ether interaction, one point of attachment, is the driving force of the enantiomer with this class of chiral selector. The two other necessary interactions are a steric and a hydrophobic one. They will occur between the crown ether substituents and the host substituent. Chiral crown ether can only discriminate chiral molecules with a primary amine group at low pH (where the amine is protonated). 

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