The impact of [1,2,5]chalcogenazolo[3,4,f]-benzo[1,2,3]triazole structure on the optoelectronic properties of conjugated polymers.

Download
2020
Aydan Alkan, Ece
[1,2,5]Chalcogenazolo[3,4-f]benzo[1,2,3]triazole units are strong electron-acceptor moieties that narrow the band gap of resulting conjugated polymers due to the electron deficiency on both sides of their structure. In this study, the effect of acceptor strength on optoelectronic properties were aimed and investigated by incorporating these moieties into donor-acceptor type conjugated polymers. Central chalcogen atom of the chalcogenazole linkage differentiated as sulfur and selenium to compare their effects on the optoelectronic properties of the polymers. Therefore, two novel conjugated near-IR (NIR) absorbing donor–acceptor type copolymers comprising [1,2,5]chalcogenazolo[3,4-f]-benzo[1,2,3]triazole derivatives as the acceptors and benzodithiophene as the donor, spaced with thiophene as the π-bridge, were designed and synthesized via Stille polycondensation reaction. Branched alkyl chains (the extended 2-octyl-1-dodecyl alkyl chain; -C8C12) were substituted to 5H-[1,2,3]triazolo[4',5':4,5]benzo[1,2-c][1,2,5]thiadiazole and 5H-[1,2,3]triazolo[4',5':4,5]benzo[1,2-c][1,2,5]selenadiazole for enhanced solubility of polymers which ease the processability hence device constructions. The strong electron-withdrawing units lead to a substantial change on the absorption properties via promoting the intramolecular charge transfer (ICT) band alongside the π–π* transition with a wide range of absorption extended to the NIR region. The resultant soluble polymers were characterized via cyclic voltammetry to determine HOMO and LUMO energy levels as -5.00 eV and -3.92 for PSBT and -4.86 eV and -4.04 eV for PSeBT, respectively. Electronic band gaps of the copolymers were calculated as 1.08 eV for PSBT and 0.82 eV for PSeBT, respectively. Finally, an electrochromic device (ECD) was constructed and characterized using the polymer PSeBT, due to its lower band gap and better switching colors displayed in all RGB than its sulfur analogue.

Suggestions

The electronic band structure of AlN, AlSb, AlAs and their ternary alloys with In
Mohammad, Rezek; Katırcıoğlu, Şenay (World Scientific Pub Co Pte Lt, 2006-09-10)
The electronic band structure of AlN, AlSb, AlAs and their ternary alloys with In has been investigated by ETB. The ETB method has been formulated for sp(3)d(2) basis and nearest neighbor interactions of the compounds and its energy parameters have been derived from the results of the present first principles calculations carried on AlN, AjSb and AlAs. It has been found that the present ETB energy parameters can produce the band structure of the compounds and their ternary alloys with In successfully.
THE EFFECT OF ALKYL-GROUPS ON CARBANION STABILITY .1. INTERACTION OF SMALL RINGS WITH ADJACENT CARBANION CENTERS
BALCIOGLU, N; SEVIN, F; EVIN, O; Peynircioğlu, Nihad Bekir (1992-02-01)
Relative kinetic acidity measurements have shown that the cyclobutyl group has the ability to stabilize an adjacent carbanion center similar to vinyl and cyclopropyl groups, although to a lesser extent. The results of semiempirical calculations (MNDO) covering all the mentioned substituents, including the isopropyl group correlate well with the experimentally determined relative kinetic acidities.
The effect of substitutional impurities on the evolution of FeAl diffusion layer
Akdeniz, Mahmut Vedat; Mehrabov, Amdulla (Elsevier BV, 1998-2-13)
The formation and growth characteristics of Fe based aluminide diffusion layers at the Fe-Al interface have been analysed in terms of interfacial interaction potentials based on the statistico-thermodynamical theory of multicomponent alloys combined with electronic theory in the pseudopotential approximation. The pairwise interatomic interaction potentials and partial ordering energies have been calculated to predict the effect of various alloying additions on the activity coefficient of Al atoms in α-Fe0.9...
The Combination of benzotriazole and n-functionalized 2,5-di(2-thienyl)-1h-pyrrole units to investigate the electrochromic properties of conjugated polymers
Rende, Eda; Çırpan, Ali; Department of Chemistry (2013)
Synthesis of new conducting polymers is desired since their electrochemical and optical properties enable them to be used as active layers in many device applications. Benzotriazole and nfunctionalized 2,5-di(2-thienyl)-1h-pyrrole (SNS Series) containing polymers showed very promising results as electrochromic materials. In order to observe the effect of the combination of these two units three new monomers 2-(6-(2,5-bis(5-methylthiophen-2-yl)-1H-pyrrol-1-yl)hexyl)-4,7-di(thiophen-2- yl)-2H-benzo[d][1,2,3]t...
The effect of the different donor units on fluorescent conjugated polymers containing 2,1,3-benzooxadiazole as the acceptor unit
Goker, Seza; Hizalan, Gonul; Ileri, Merve; Hacioglu, Serife O.; Toppare, Levent Kamil (2015-08-15)
A series of monomers were synthesized via Stille coupling to obtain low-band gap conjugated polymers namely poly(5,6-bis(octyloxy)-4,7-di(thieno[3,2-b]thiophen-2-yl)benzo[c][1,2,5]oxadiazole (PTTBO)), poly(5,6-bis(octyloxy)-4,7-di(selenophen-2-yl)benzo[c][1,2,5]oxadiazole (PSBO)) and poly(5,6-bis(octyloxy)-4,7-di(furan-2-yl)benzo[c][1,2,5]oxadiazole (PFBO)) which comprise electron-rich thieno[3,2b]thiophene (TT), selenophene and furan, as the donor units in conjugation with electron-deficient 2,1,3-benzooxa...
Citation Formats
E. Aydan Alkan, “The impact of [1,2,5]chalcogenazolo[3,4,f]-benzo[1,2,3]triazole structure on the optoelectronic properties of conjugated polymers.,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Chemistry., Middle East Technical University, 2020.