Benzo bithiophenes

Benzo[bIthiophenes and Benzo[b]furans Reactions and Synthesis 435... 

Biogenic amines, such as histamine [131], adenine [132], dopamine [133] and melamine [134], have been determined using chemosensors combining MIP recognition and PM transduction at QCM. Electronically conducting MIPs have been used in these chemosensors as recognition materials. Initially, functional electroactive bis(bithiophene)methane monomers, substituted either with the benzo-18-crown-6 or 3,4-dihydroxyphenyl, or dioxaborinane moiety, were allowed to form complexes, in ACN solutions, with these amines as templates. Subsequently, these complexes were oxidatively electropolymerized under potentiodynamic conditions. The resulting MIP films deposited onto electrodes of quartz resonators were washed with aqueous base solutions to extract the templates. 

Fig. 4 Resonant frequency changes with time due to repetitive FIA melamine injections, for the MIP-QCM chemosensor. Melamine concentration is indicated with number at each curve. Inset shows FIA calibration plots for (1) melamine and its interfering compounds, such as (2) ammeline, (3) cyanuric acid, and (4) cyromazine. Volume of the injected sample solution was 100 pL. The flow rate of the 1 mM FIC1 carrier solution was 35 pL min-1. The MIP film was prepared by electropolymerization of 0.3 mM bis(2,2 -bithienyl)-benzo-[18-crown-6]methane functional monomer and 0.3 mM 3,3 -bis[2,2 -bis(2,2 -bithiophene-5-yl)]thianaphthene cross-linking monomer, in the presence of 0.1 mM melamine, in the trihexyl(tetradecyl)phosphonium tris(pentafluor-oethy 1)-trifluorophosphate ionic liquid ACN (1 1 v/v) solution, which was 0.9 mM in trifluoroacetic acid (pH = 3.0). The melamine template was extracted from the MIP film with 0.01 M NaOH before the determinations (adapted from [134])...

Transition metal catalyzed processes are useful tools for the synthesis of functionalized thiophenes. Thus for instance, a phosphine-free, palladium catalyzed coupling protocol for the synthesis of 2-arylbenzo[d]thiophenes from various 3-substituted benzo[6]thiophenes and aryl bromides or iodides has been reported <04T3221>. Likewise, 2,2 -bithiophenes have been 5,5 -diarylated directly with aryl bromides in the presence of Pd(OAc)2, bulky phosphine ligands and CS2CO3 <04T6757>. A series of electron-deficient and relatively electron-rich benzo[6]thienyl bromides have been shown to participate in palladium catalyzed amination reactions, as exemplified by the interesting conversion of 63 to the tetracyclic system 64 upon reaction with 2-aminopyridine 65 <04EJO3679>. 

Poly [benzo(l,2-d 4,5-d )bisthiazole-2,6-diyl]2,5-thiophenediyl (a) Poly [benzo(l,2-d 4,5-d )bisthiazole-2,6-diyl]2,2 -bithiophene-5,5 -diyl (b) Poly [benzo(l,2-d 4,5-d )bisthiazole-2,6-diyl]2,2 5, 2"-terthiophene-5,5"-diyl (c) [27]... 

MatanoY, MiyajimaT, FukushimaT, Kaji H, Kimura Y, Imahori H (2008) Comparative study of the synthesis, structures, and optical and electrochemical properties of bithiophene-fused benzo[c]phospholes. Chem Eur J 14 8102-8115... 

A. Pietrzyk et al. reported an imprinted poly[bis(2,2 -bithienyl)methane] film for a piezoelectric microgravimetry of dopamine. The MIP film contained either a 3,4-dihydroxyphenyl or benzo-18-crown-6 substituent, for selective determination of dopamine and was electropolymerized on an imderlayer of poly(bithiophene) on a Pt/ quartz resonator. The detection limit of the method was reported to be 10 nM [401]. Kan et al, on the other hand, developed a composite of multiwalled carbon nanotube (MWCNTs) and MIP with dopamine templates using the copolymerization reaction of methacrylic acid and trimethylolpropane trimethacrylate (copoly(MAA-co-TRIM)) on the vinyl functionalized MWCNT surface and used the composite for the thermo-gravimetric analysis of the template. The composite was found to be selective towards dopamine in comparison with epinephrine and the response was linear in the range of 5.0 X 10 "-2.0 X 10 M [427]. 

A number of copolymers containing two thiophene rings and one benzo[c]thiophene or a derivative of benzo-[c]thiophene in the repeat unit have been reported. The rationale was to combine a unit that prefers the quinonoid structure in a polymer with thiophenes that prefer the aromatic form in order to form a low band gap polymer. Lorey and Cava [74] prepared copolymer 35, poly-(benzo[c]thiophene-fl//-bithiophene) by the route shown in Scheme 10, and this same polymer was prepared independently by Musmanni and Ferraris [75] and by Bauerle... 

A related polymer (104), poly(benzo[l,2-c 4,5-c ] bis (1,2,5 - thiadiazole) - 4,8 - diyl - alt - bithiophene), which contains two 1,2,5-thiadiazole rings fused onto... 

Fig. 19 Common organic semiconductors used in organic solar cells a poly[2-methoxy-5-(3, 7 -dimethyloctyloxy)-l,4-phenylenevinylene] (MDMO-PPV), b perylene, c poly(triaryl amine), d poly[(9,9-di-n-octylfluorenyl-2,7-diyl) ((F8T2)), e Phenyl-C61-butyric acid methyl ester-alt-2,2 -bithiophene-5,5 -diyl)] (PCBM), f poly( 4,8-bis[(2-ethylhexyl)oxy]benzo[l,2-h 4,5-b ] dithiophene-2,6-diyl 3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-h]thiophenediyl ) (PTB7)...

---