Pentoxy groups

With the aim of getting a better understanding of the structural requirements for effective complexation, two series of linear oligomers (propoxy and pentoxy groups) were prepared up to the pentamer.17 For the pentoxy series (051 n = 0, Os2 n= 1, Os3 n = 2,054 n = 3,055 n = 4), complexation constants with europium have been determined out in methanol in comparison to CPw3 (Table 4.24) (see Section 4.7). 

Experimental results show that the reinforcement depends primarily on the EP -f PLC miscibility, PLC concentration, and sizes and shapes of the islands. A method of miscibility improvement was developed by Schleeh, Kossmehl, and Hinrichsen [86-88] who synthesized poly(p-phenylene terephthalates) with pentoxy groups as flexible side chains. Needless to say, such side chains mix well with EPs. 

The regioisomeric 4,4 -dipentoxy-2,2 -bithiophene 327 bearing the pentoxy groups in the outer /3-positions was synthesized in 70% yield by oxidative coupling of lithiated 3-pentoxythiophene 321 with copper chloride. 4-Pentoxy-2-thiophene-boronic acid 326 which was synthesized from 3-pentoxythiophene 321, lithiumdiiso-propylamid and trimethylborate was coupled with I-Tj-I 54 and I-T2—I 306,... 

The photoreduction of the above dye, 5,7-diiodo-3-pentoxy-9-fluorenone, in the presence of (phenylthio)-acetic acid and its tetrabutylammonium salt occurs via a photoinduced electron transfer process. On the basis of the known photochemistry of sulfur-containing aromatic carboxylic acids, it is postulated that the existence of the carboxyl group in an ionic form allows a rapid decarboxylation, yielding a neutral very reactive a-alkylthio-type radical (R-S-CH2 ). 

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