Synthesis of Functionalized Polythiophene as a Potenial Organic Semi-Conductor

Abstract

Abstract. The synthesis Poly [1,5-naphthyridine-(3-hexylthiophene)] (PN3HTh) semi-conducting polymer has been accomplished by adopting both conventional and microwave-assisted Suzuki-Miyaura cross-coupling reaction between 3-hexylthiophene-2,5-diboronic ester and 2,6-dibromo-1,5-naphthyridine. The electrochemical and transport properties of PN3HTh were investigated both in the bulk as well as in thin film form. These properties can be further tuned by changing the solvent and the nature of the electrode used. Consequently, cyclic voltammetry (CV) measurements were conducted using a potentiostat coupled with an electrochemical cell. The CV results of PN3HTh as a bulk form in H2SO4 solution indicated that the concentration of the polymer in the solution is not well defined because of polymer poor solubility in aqueous solutions. On the other hand, the sulfur group which works as electron donating makes the system more electron-rich. This can explain by the absence of the reduction peak. For the thin film, two single oxidation peaks were obtained at around 0 V and 0.3 V for both cases. Different solvents can tune the transport properties of the polymer as can be seen from the two CVs where BF3 exhibited enhanced transport properties over ACN. The synthesized polymers were characterized by modern spectroscopic methods including IR and NMR.

Synthetic Strategies, Reactivity and Applications of 1,5-Naphthyridines

“…Through an alternative cyclization process, the core of 1,5-naphthyridine 31 was accomplished by treatment of the corresponding pyridine 30 with diethyl oxalate, subsequent reduction of the nitro and carbonyl functions with aluminium borohydride, followed by concomitant lactamization ( Scheme 10 ) [ 40 ].…”

“…Other halogenation reactions were carried out in the preparation of fluorine intermediates (compounds 74 and 75 , Figure 2 ) [ 26 ]. In this sense, the reaction was applied for the synthesis of 1,5-naphthyridine-based polymers, new functional materials for electronics (compound 76 , Figure 2 ) [ 40 ], active naphthyridine derivatives for the development of novel anti-Ebola virus pharmacophore (compound 77 , Figure 2 ) [ 27 ], a series of naphthyridine derivatives as bromo domain inibitors (compound 72a , Figure 2 ) [ 24 ], for the development of some novel 1,5-naphthyridines as c-Met kinase inhibitors (compound 78 , Figure 2 ) [ 9 ], for the synthesis of a 1,5-naphthyridine analogues of a first in class Rpn 11-selective proteasome inhibitor (compound 79 , Figure 2 ) [ 34 ] or for the synthesis of 1,5-naphthyridine-based DYRK1A inhibitors (compound 80 , Figure 2 ) [ 21 ].…”

“…This strategy was also used for the double incorporation of alkyl or aryl groups into the skeleton of 1,5-naphthyridines. The last step to obtain the 2,6- bis (4-(9,9-dimethylacridin-yl)phenyl)-1,5-naphthyridine 161 was a Suzuki-Miyaura coupling between the chlorinated 2,6-naphthyridine 120 (previously prepared, vide supra, Scheme 44 ) and (4-(9,9-dimethylacridin-10(9 H )-yl)phenyl) boronic acid 160 ( Scheme 68 ) [ 40 ].…”

“…In a similar way, the synthesis of poly [1,5-naphthyridine-(3-hexylthiophene)] semi-conducting polymer 163 has been accomplished by adopting both conventional and microwave-assisted Suzuki-Miyaura cross-coupling reaction between 3-hexylthiophene-2,5-diboronic ester 162 and 2,6-dibromo-1,5-naphthyridine 76 (previously prepared, vide supra, Figure 1 ) ( Scheme 69 ) [ 40 , 97 ].…”

“…Poly[1,5-naphthyridine-(3-hexylthiophene)] semi-conducting polymer 166 (previously prepared, vide supra, Scheme 70 ) has been accomplished to be used as polymer-sensitized solar cell ( Figure 42 ) [ 40 ]. In this case, solar cells are assembled using functionalized polythiophenes as a photoactive layer offering interesting properties [ 97 ].…”