Poly copolymer with 3-methylthiophene

A regiorandom copolymer of 3-methylthiophene and 3-butylthiophene possessed a conductivity of 50 S/cm, while a more regioregular copolymer with a 2 1 ratio of HT to HH couplings had a higher conductivity of 140 S/cm. Films of regioregular poly[3-(4-octylphenyl)thiophene] (POPT) with greater than 94% HT content possessed conductivities of 4 S/cm compared to 0.4 S/cm for regioirregular POPT. 

With the aid of NMR spectroscopy ( H- H NOESY) for PDDT and its copolymer with 3-methylthiophene in deuterated chloroform, the configurational structures were determined [90,91]. The 3-dodecylthiophene monomer is proved to be attacked predominantly at the p position of the thiophene ring (head) with a probability of 82% during the electrochemical polymerization [90]. PHT prepared by using a zero-valent nickel complex contains a larger proportion of HH units than HT units [92]. Chemically polymerized poly-(3-cyclohexylthiophene) contains HT and HH-TT coupled components in the ratio of 7 3 [93]. 

Nonlinear optical properties of PTs which exhibit ultrafast responses and large nonlinearities attributed to one-dimensionality and delocalization of n-electrons along the polymer chains are also described [403,404]. Poly(4,4 -dipentoxy-2,2 -bithiophene) and poly(4,4 -dipentoxy-2,2 5, 2"-terthiophene) show a fast and high third-order nonlinearity [405]. Third-order nonlinearities depend on the nature of the polymer backbone and only slightly on the substituents [406], The optical transparency and the third-order optical nonlinearities can be tailored in random copolymers of 3-methylthiophene and methyl methacrylate [407]. A solution-processable thiophene copolymer with a side... 

Figure 11. Cyclic votammetry (top) and in situ electronic conductivity from rotating-disk voltammetry [ , Fig. 9(C)] and sandwich electrode voltammetry [ , Fig. 9(B)] for poly(3-methylthiophene) in acetonitrile containing 0.1 M BU4CIO4.60 (Reprinted from J. Ochmanska and P. G. Pickup, In situ conductivity of poly-(3-methylthiophene) and (3-methylthiophene)x,-[Ru(2,2 -bipyridine)2 (3- pyrrol-l-ylmethyl pyridine)2]2+ copolymers, J. Electroanal. Chem. 297, 211-224, 1991, with kind permission from Elsevier Sciences S.A.)...

A copolymer of pyrrole and thiophene nano-fibrUs was electrochemically polymerized within the pores of microporous, anodic, aluminum oxide template membranes [105]. The copolymer nucleated and grew on the pore wall of the membrane since the polymers were cationic and the membrane had anionic sites on the pore wall. The length, thickness, and diameter of the copolymer nanofibrils could be controlled and with higher applied potential, more thiophene units were incorporated into the copolymer nanofibrUs [105]. Copolymer nanofibrils of pyrrole and aniline were also electrochemically polymerized within the pores of microporous, anodic, aluminum oxide template membranes [106]. Copolymer nanofibrils of PPy and poly(3-methylthiophene) prepared chemically in the microporous aluminum oxide template showed higher conductivity than the homopolymers did [107]. 

In addition to the P[3MT-MG8] series of MIEC block copolymers prepared in our laboratories, a third series of block copolymers, poly(3-methylthiophene-co-3-octylthiophene)-block-poly[o>-methoxyocta(oxyethylene)methacrylate], abbreviated P[3MT,30T-MG8], have been synthesized. The reason we selected random copolymers of 3MT and 30T for the electronic conductive block is to combine the solubility and fusibility of SOT with the chemical and electrochemical stability of... 

The conductivity of poly(3-butylthiophene) prepared electrochemically in PC containing Et4NPp6 is 110 S cm [42-4] and 40 S cm in nitrobenzene containing BU4NCIO4 [45-6]. In a significant and innovative contribution, researchers [46, 47] at Allied-Signal prepared copolymers of 3-methylthiophene and 3-butylthiophene (1 1) that are highly conductive, environmentally stable and solution-processable. The conductivity of a pellet of polymer doped with iodine is... 

Electrical conductivity of the iodine-doped copolymer prepared via the first route is 10 S cm and l Scm for the copolymer prepared by the second route. The conductivity of the 10 1 (3-MT/ MMA) copolymer after iodine doping is 0.2 S cm , indicating that conductivity increases with increasing concentration of thiophene units. Quantitative data on the solubility of doped poly(3-butylthiophene) and poly(3-methylthiophene-co-3-butylthiophene) are... 

The polymerization reaction, i.e., the reaction of two radical cations or the reaction of a radical cation with a neutral monomer molecule, depends on the conditions during electrochemical polymerization [58, 627, 629, 630]. During the electrocopolymerization of 3-methylthiophene and 3-thienylacetic acid, a radical cation (of 3-methylthiophene) attacks at a neutral monomer (3-thienylacetic acid). It is possible to produce the copolymer at a potential at which only one of the monomer species can be oxidized [108]. Fig. 19 shows a partial model of interfacial reactions taking place during the electrogeneration of PT or poly(pyrrole) from acetonitrile solutions containing the electrolyte LiClO. . The relative influence of each of these reactions depends on the chemical and electrical conditions of synthesis [629] ... 

NEXAFS spectroscopy can be applied for quantitative analyses of the chemical composition of polymer blends and copolymers [9]. An interesting application concerns NEXAFS microscopy (see Section 6.3). Moreover, the application of NEXAFS spectroscopy to surface studies -and in particular to studies related to the adsorption of organic molecules onto the surfaces of metals and polymers - is of particular interest. For example, the NEXAFS spectra of a monolayer of poly-3-methylthiophene, electrochemically grafted onto Pt, revealed that the aromatic rings in the polymeric layer are Jt-bonded to the Pt(lll) surface [16]. In addition, NEXAFS spectroscopy provides answers to questions such as Flow do molecules interact with surfaces or How do molecules orient on surfaces ... 

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