1,4-phenylene ethylene

H. Meier, H. Kretzshmann, and M. Lang, Synthesis of 2-alkoxy substituted oligo and poly( 1,4-phenylene-ethylene)s and 2-arylbenzo[/ ]furanes by applying the Siegrist reaction,5. Pra/c Chem. 336. 1 (1994). 

Poly(2-bromo-l,4-phenylene efliylene) Poly(2-chloro- 1,4-phenylene ethylene)... 

D. Ofer, T.M. Swager, and M.S. Wrighton, Solid-state ordering and potential dependence of conductivity in poly(2,5-dialkoxy-/j-phenylene ethylene), Chem. Mater., 7 418-425, 1995. 

Moon JH, Deans R, Kruegar E, Hancock LF (2003) Capture and detection of a quencher labeled oligonucleotide by poly(phenylene ethylene) particles. Chem Commun 1 104-105... 

A linear phenylene-ethylene copolymer is obtained by a Wurtz-type condensation of 1,2-dibromoethane and 1,4-dibromobenzene. A cross-linked variation can be obtained on addition of 1,3,5-tribromobenzene to the reaction mixture. Equation 119 illustrates the reductive scission of a cyclic ether, catalyzed by such polymers in the presence of lithium, followed by quenching with cyclohexanone . 

Tridentate ligands of the linear type having donor sets P3, AS3 or P As3. t, where the donor atoms are connected by o-phenylene, ethylene or trimethylene chains, were found to form stable complexes with nickel(II) salts.1350 Listings of the most common ligands and nickel(II) complexes are given in Tables 67 and 68, respectively. 

TCNE = Tetracyanoethylene Dipdba = 4,4 -diisopropyl(di-benzylideneacetone) TMM = Trimethylenemethane dppm = (Diphenylphosphino)methane MMLCT = Metal-metal bond to ligand charge-transfer Tp = Hydrido(trispy-razolyl)borate Tp = Hydridotris(3,5-dimethyl-pyrazolyl)bo-rate BAr = (3,5-triflnoromethylphenyl)borate ttab = l,2,4,5-tetrakis(l-iV-7-azaindolyl)benzene tmeda = Tetra-methylethylenediamine bpma = Bis(pyridyhnethyl)amine TFE = Triflnoroethanol dtbpm = Bis(di-terr-butylphosphi-no)methane dmpe = Bis(dimethylphosphino)ethane dcpe = Bis(dicyclohexylphosphino)ethane triphos = Bis(2-diphe-nylphosphinoethyl)phenylphosphine COD = 1,5-cycloocta-diene dppbts = (Diphenylphosphinobutane)tosylate sodium PPE = Poly(jo-phenylene ethylene). 

Fig. 8 The structure of the ureidopyrimidinone (Upy) end-capped, pendant iptecene poly(p-phenylene ethylene) derivative (10) prepared by Hoogboom and Swager [72] to investigate alignment in the liquid crystal 4-n-pentyl-4 -cyanobiphenyl (5CB)...

Poly [oxy-(2,6-dimethyl-l,4-phenylene)-ethylene-(2,6-dimethyl-1,4-phenylene) ... 

Fig. 68. Loss in weight of various polyphenylene-type polymers after heating in vacuo for 2 h at different temperatures [276]. A, poly-p-2,3,5,6-tetramethylphenylene methylene B, poly-9,10-anthrylene ethylene C, poly-p-2,5-dimethoxyphenylene ethylene D, poly-p-2,5-dimethylphenylene methylene E, poly-p-phenylene ethylene F, poly-p-2,3,5,6-tetramethylphenylene ethylene G, poly-2,6-naphthylene ethylene H, poly-p,p -diphenylene methylene I, poly-m-phenylene J, poly-p-phenylene.

Poly [ 1,4-phenylene-1,2-di(4-benzyloxyphenyl)vinylene], 42 Poly(phenylene ether), 139 Poly(1,4-phenylene ether sulfone), 250, 256 Poly(p-phenylene ethylene), 69 Poly(l,4-phenylene ethynylene), 105 Poly(p-phenylene ethynylene), 89 Poly(m-phenylene isophthalamide), 439 Poly(p-phenylene methylene), 69... 

Instructed, reproducible self-assembly of this type can be seen in numerous disciplines. In polymer chemistry, certain oligo(phenylene ethylenes) undergo solvophobic folding into helical conformations in polar solvents. " In peptide science, synthetic polypeptides containing unnatural P-amino acids spontaneously adopt helical dispositions in solution, despite being unable to form the hydrogen bonds that drive self-assembly in normal biopolymers. 

There have been many attempts to change the melt flow properties of a polymer by incorporating a small amount of an anisotropic or an immiscible polymer. For example, Brody [220,221] demonstrated a windup speed up to 5000 m/min by adding a small amount of copoly(chloro-l,4-phenylene ethylene dioxy-4,4 -dibenzoate/terephthalate) (CLOTH) or copoly(4-hydroxybenzoic/6-hydroxy-2-naphthoic acid) into nylon-6,6. More recently, Vassi-latos [222] disclosed the melt spinning of nylon-6,6 at speeds up to 6000 m/min with the addition of a minor amount of liquid crystalline polymers such as CLOTH. This technique clearly offsets some of the cost advantages of high-speed spinning. 

As a variant of this first method using Grignard reagents to prepare hybrid silicones, it may be cited a very recently published synthesis of poly(sil-oxylene-ethylene-phenylene-ethylene)s by reaction of a bis-chlorosiloxane with the bismagnesium derivative of a diethynyl compound [29,30] according to the following scheme ... 

MBPE-9, see poly[oxy-l,4(3-methyl-phenylene)ethylene-l,4-phenyleneoxynona-methylene]... 

The second column of Table 6.7 gives the y values estimated from Ps. There is a rather large discrepancy from those obtained by contact angle experiments (which is in the last column). Clearly, the parachor approach is not suitable for the surface tension estimation of TLCPs. The third column summarizes the ys estimated from Ecoh- In order to calculate Ecoh values, three structural group contribution tables have been chosen and evaluated. They are Hoftyzer and Van Krevelen, Hayes, and Fedors tables [60]. The Ecoh value used for the p-naphthalene group is estimated from a combination of Ecoh values of p-phenylene, ethylene, and other groups. For readers information, Hoftyzer and Van Krevelen and Hayes do not provide Ecoh value for the p-naphthalene group. 

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