Poly arenes

The area of chiral polymers is also a field of growing interest, with chiral structures reported for polymethacrylate esters and polyacetaldehydes, polytriha-loacetaldehydes, polythiophenes, polyquinoxalin-2,3-diyles, poly-arene-... 

Figure 14 represents very logical relationships between impact sensitivity and the net charges of the primarily reacting nitro group here linear condensed polynitro (poly)arenes are sharply separated from spatially con-... 

Rhodium-catalyzed enantioselective hydrogenation of acctamido -cinnamic in water was also achieved using pyrphos bound to poly-acrylic acid as ligand.337 Roucoux described some Rh° nanoparticles which function as reusable hydrogenation catalyst for arene derivatives in a biphasic water-liquid system.338... 

M. Vazquez, J. Bobacka, M. Luostarinen, K. Rissanen, A. Lewenstam, and A. Ivaska, Potentiometric sensors based on poly(3,4-ethylenedioxythiophene) (PEDOT) doped with sulfonated calix[4]arene and calix[4]resorcarenes. J. Solid State Electrochem. 9, 312-319 (2005). 

The most prominent application of the Ru-arene chemistry has been for the preparation of biaryl ethers in the syntheses of portions of vancomycin,467 ristocetin (Equation (127)),462,468-473 and teicoplanin (see also Section 10.14.1.2).474-476 Additional applications477-479 have included the syntheses of the macrocyclic biaryl ether-containing compounds K-13480,481 and OF4949-III,481,482 several macrocyclic depsipeptides,483,484 and poly(phenylene oxide) polymers.485... 

Finally, these particles generated in ionic liquids are efficient nanocatalysts for the hydrogenation of arenes, although the best performances were not obtained in biphasic liquid-liquid conditions. The main importance of this system should be seen in terms of product separation and catalyst recycling. An interesting alternative is proposed by Kou and coworkers [107], who described the synthesis of a rhodium colloidal suspension in BMI BF4 in the presence of the ionic copolymer poly[(N-vinyl-2-pyrrolidone)-co-(l-vinyl-3-butylimidazolium chloride)] as protective agent. The authors reported nanoparticles with a mean diameter of ca. 2.9 nm and a TOF of 250 h-1 in the hydrogenation of benzene at 75 °C and under 40 bar H2. An impressive TTO of 20 000 is claimed after five total recycles. 

A first generation poly(amido amine) dendrimer has been functionalized with three calyx[4]arenes, each carrying a pyrene fluorophore (4) [30]. In acetonitrile solution the emission spectrum shows both the monomer and the excimer emission band, typical of the pyrene chromophore. Upon addition of Al3+ as perchlorate salt, a decrease in the excimer emission and a consequent revival of the monomer emission is observed. This can be interpreted as a change in the dendrimer structure and flexibility upon metal ion complexation that inhibits close proximity of pyrenyl units, thus decreasing the excimer formation probability. 1H NMR studies of dendrimer 4 revealed marked differences upon Al3+ addition only in the chemical shifts of the CH2 protons linked to the central amine group, demonstrating that the metal ion is coordinated by the dendrimer core. MALDI-TOF experiments gave evidence of a 1 1 complex. Similar results have been obtained for In3+, while other cations such as Ag+, Cd2+, and Zn2+ do not affect the luminescence properties of... 

Bunz UHF (2002) In Astruc D (ed) Modern arene chemistry. Wiley-VCH, pp 217-249 The ADIMET reaction synthesis and properties of poly(dialkyl para-phenyleneethynylene)s... 

Table 4. Conversion of Arenepolycarboxylic Acids into Poly(trifluoromethyl)arenes...

The third group ofpolychromophoric compounds to be discussed are homopolymers in which the pendant rings are separated from the backbone by one or more atoms. The polymers of allyl arenes, which lack only the n = 3 ring spacing of aryl vinyl polymers, have been studied very little. The fluorescence spectrum of poly(l-allyl-naphthalene) in dilute dichloromethane solution has been reported 28). Like 1-ethyl-naphthalene, the maximum intensity was seen at 337 nm, but a weak, broad shoulder was also recorded for the polymer at 410 nm. The fluorescence ratio Iu/IM for poly(l-allylnaphthalene) was only 1/100 th the value for P1VN 28). The excimeric nature of the 410 nm emission in the allyl-based polymer has not been confirmed, since neither the lifetime nor the excitation spectrum of this fluorescence band are known. 

Table 6. Poly(alkylsulfanyl)- and Poly(arylsulfanyl)arenes from Polyfluoroarenes by Complete Replacement of Fluorine by Alkyl- or Arylsulfanyl Groups...

Poly(alkylsulfanyl)- and Poly(arylsuIfanyl)arenes General Procedure 57... 

M. J. Bowden and E. A. Chandross. 1975. Poly(vinyl arene sulfones) as novel positive photoresists. Journal of the Electrochemical Society 122 1370-1374. 

Recent developments in this area include the use of poly[hydroxy(tosyloxy)-iodo]styrenes [80], chiral 2-(a-alkoxyalkyl) analogs of [hydroxy(tosyloxy)-iodo]benzene [81 - 83], and iodine(III)-phosphonate and -phosphinate reagents [84] for C-oxygen bond formation at a-carbon. Oxysulfonylations at the a-carbon atoms of carboxylic anhydrides with [hydroxy(sulfonyloxy)iodo]arenes have also been documented [85]. 

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