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

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.


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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.
BALCIOGLU, N; SEVIN, F; EVIN, O; Peynircioğlu, Nihad Bekir (1992-02-01)
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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 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...
The Site Preferences of Transition Elements and Their Synergistic Effects on the Bonding Strengthening and Structural Stability of gamma '-Ni3Al Precipitates in Ni-Based Superalloys: A First-Principles Investigation
Eriş, Rasim; Akdeniz, Mahmut Vedat; Mehrabov, Amdulla (2021-04-01)
Advanced mechanical properties of Ni-based superalloys strongly depend on the site preferences of alloying X elements in gamma '-Ni3Al-X precipitates, which are associated with the partial bonding characteristics between Ni, Al, and X atoms. Therefore, in the current work, the site occupancy tendencies of transition X metals were revealed via first-principles ab initio calculations at 0 K. Bonding features of Ni-Al, Ni-X, and Al-X pairs were simulated by using the charge density difference (CDD), electron l...
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.