Propyl Orange

Gels prepared with Methyl orange Ethyl orange Propyl orange Butyl orange... 

Among the many desirable properties that are obtained with sol-gel formed metal oxide materials, it is perhaps the hydrophilic/hydrophobic duality of the matrix that allows the successful imprinting of molecular species. In the formation of the gel, templates will direct the placement of siloxane and silanol groups to complementarily interact with various hydrophobic and hydrophilic sites on the template. Figure 8.4 shows a possible form of an imprinted site for propyl orange in a silica matrix. Various aspects of molecular imprinting, such as these concepts, will be explored in the following sections. 

Fig. 8.4. Schematic of an imprinted site in a silica gel matrix using propyl orange as the template. The flexible hydrophobic/hydrophilic nature of the metal oxide gel matrix provides for appropriate siloxane/silanol formation to accommodate the functionality and structure of the imprinting molecule.

A very sensitive method for determining calcium is based on the complex of Ca with the chromogenic macrocyclic reagent (formula 14.4) (1,2-dichloroethane, e = 5.5-10 at 406 nm) [65]. Other diaza-crown ethers have been also used in determinations of Ca (and Mg) [66]. Calcium has been determined after extraction (CHCI3 + benzene) with the crown ether and association with Propyl Orange [67]. 

Calcichrome has been used for determination of calcium in soil extracts [81] and in poly(ethylene terephthalate) [82], Calcium has been determined in river water with Propyl Orange after extraction with a crown ether [67]. 

C-FIA membrane for phase [457] separation ion association between Ca-crown complex and propyl orange... 

S. Motomizu, M. Oshima, N. Yoneda, T. Iwachido, Spectrophotometric determination of calcium with dicyclohexano-24-crown-8 and propyl orange by solvent-extraction flow-injection method, Anal. Sci. 6 (1990) 215. 

Methyl-orange (R = Me) Ethyl-orange (R = Et) Propyl-orange (R = Pr) Butyl-orange (R = Bu)... 

Orange RO acid orange 8, l,8-[bis(4-n-propyl-3-sulfopbenyl-l-amino)]antbra-9,10-quinone di-Na salt] [5850-86-2] M 364.4, Cl 15575, Xmax 490nm. Salted out three times with sodium acetate, then repeatedly extracted with EtOH. 

In a second Schlenk tube were placed under nitrogen tert-butyl acetoacetate and dry 2-propanol (14 mL). The mixture was degassed and added to the first solution. Finally, degassed potassium 2-propylate solution (1 mL) was added. The resulting orange solution was stirred at room temperature. 

The solvent was removed using a rotatory evaporator, and the resulting residue was diluted with ether (50 mL). The diamine was extracted with 10% phosphoric acid (3 x 15mL), after which the aqueous layer was made alkaline (pH 9) with 10 % sodium hydroxide solution (100 mL). The resulting mixture was extracted with ether (5 x 50 mL). The combined ethereal extracts were dried over anhydrous potassium carbonate, filtered and concentrated in vacuo to afford the pure (f ,i )-l,l -bis [a-(dimethylamino) propyl]ferrocene as an orange solid (11.4 g, 98.0%). 

Here are some additional examples of esters as aromas or flavors propyl acetate is the aroma of pears pentyl acetate is the aroma of bananas octyl acetate is that for oranges. 

Methyl (3-hydroxy)propyl telluride (typical procedure) MeTeLi. A suspension of Te powder (12.8 g, 0.1 mol) in THE (100 mL) is frozen in a liquid N2 bath, and then MeLi (66.7 mL of a 1.5 M solution in ether, 0.1 mol) is injected into the flask. The mixture is allowed to thaw and is stirred magnetically for a further 30 min at room temperature. The resulting yellow-orange solution is stored under N2 and used within 2 h. 

Diselenopropylamine hydrochloride, Se2(CH2.CH2.CH2.NH2)2. 2HC1, obtained from propyl-y-diselenidodiphthalamic acid in a similar manner to the foregoing ethyl compound, separates from alcohol in crystals of melting-point 170° C. The picrate, C6H16N2Se2.2C6H3N307, forms orange crystals, M.pt. 165° C. 

Methyl orange, 7, 20 4-Methyl Pentanone-2, 7, 62 Methyl propyl carbinol, 7, 76 Methyl Red, 2, 47 Methyl sulfate, 6, 96 7, 26 Michael Reaction, 4, 29... 

At a lecture delivered in Philadelphia s Franklin Institute on March 17, 1949, Pauling reported some of the results from Dickey s experiments [23]. Silica gels had been prepared by procedures analogous to the formation of antibodies , i.e. in accordance with the selective theory, and the study was published later the same year [24]. The method described involved polymerisation of sodium silicate in the presence of a dye. Four different dyes were used, namely methyl, ethyl, /i-propyl and -butyl orange (Fig. 1.3). As much as possible of the dye was subsequently removed, and in rebinding experiments it was found that silica prepared in the presence of any of these pattern moleeules would bind the pattern molecule in preference to the other three dyes. Table 1.2 shows the selective increase in pattern dye sorption capacities of the gels as related to a control gel, prepared in the absence of dye. 

R = methyl, ethyl, propyl, butyl Orange dyes... 

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