Absorption and emission properties of carbazole-based dyads studied from experimental and theoretical investigations

Belletête, Michel; Bédard, Mélanie; Leclerc, Mario; Durocher, Gilles

doi:10.1016/j.synthmet.2004.06.012

Cited by 23 publications

(10 citation statements)

References 25 publications

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“…All starting organic compounds were purchased from Aldrich Co. and used without further purification. N-Octyl-2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)carbazole (12), Pd(PPh 3 ) 4 (18), N-octyl-2- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)carbazole (19), 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9-dioctylfluorene (20), and 2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9-dioctylfluorene (21) were synthesized following procedures reported in the literature.…”

Section: Methodsmentioning

confidence: 99%

Spectroscopic and photophysical properties of carbazole-based triads

Belletête¹,

Bédard²,

Bouchard³

et al. 2004

Can. J. Chem.

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A study of the spectroscopy and photophysics of four carbazole-based triads, namely, 1,4-bis(N-octylcarbazol-2-yl)phenylene (CPC), 2,5-bis(N-octylcarbazol-2-yl)thiophene (CTC), 2,7-bis(N-octylcarbazol-2-yl)-9,9-dihexylfluorene (CFC), and 2,7-bis(N-octylcarbazol-2-yl)-N-octylcarbazole (CCC) are reported. From ZINDO/S calculations performed on the optimized ground state geometries (HF/6-31G*), the S 1 ← S 0 and S 2 ← S 0 electronic transitions of CPC, CFC, and CCC are weakly allowed, whereas the S 3 ← S 0 electronic transition is dipole-allowed (x axis) and possesses a high value of the oscillator strength. On the other hand, for CTC, the dipole-allowed electronic transition is S 1 ← S 0 . For the four derivatives, the dipole-allowed transition corresponds mainly to the promotion of an electron from the HOMO to the LUMO. The first absorption band of each derivative can be assigned to the dipole-allowed transition. The geometry optimization of the excited states has been done with RCIS/6-31G* ab initio calculations. For CPC, CFC, and CCC, S 3 is much more stabilized than S 1 and S 2 , causing a crossing of the singlet excited states (S 3 becomes lower in energy than S 1 and S 2 ). Emission energies from the first relaxed excited states (S 1 → S 0 ) have been obtained from ZINDO/S calculations performed on the optimized S 1 geometries (RCIS/6-31G*). It is found that these energies are in very good agreement with those determined from the fluorescence spectra. Going from CPC to CTC, the replacement of a phenylene ring by a thiophene unit induces a red shift in the absorption and fluorescence spectra. This behavior is interpreted in terms of the electron donor properties of the thiophene ring. The increase of the oligomer chain (CFC and CCC compared to CPC) also induces bathochromic shifts in the spectra because of a longer electronic delocalization along the molecular frame. From fluorescence data, it is observed that a more planar conformation is favored in the relaxed excited states. RCIS/6-31G* ab initio calculations performed on the S 1 relaxed excited states confirm this statement. Finally, the photophysical properties of CTC are mainly governed by nonradiative processes (k nr ), whereas the variation in the photophysics of CPC, CFC, and CCC mainly involves radiative processes (k F ).Résumé : Une étude de la spectroscopie et de la photophysique de quatre dérivés du carbazole, soit 1,4-bis(N-octylcarbazol-2-yl)phenylene (CPC), 2,5-bis(N-octylcarbazol-2-yl)thiophene (CTC), 2,7-bis(N-octylcarbazol-2-yl)-9,9-dihexylfluorene (CFC), et 2,7-bis(N-octylcarbazol-2-yl)-N-octylcarbazole (CCC) est reportée. À partir de calculs ZINDO/S effectués sur les géométries à l'état fondamental optimisées (HF/6-31G*), il est démontré que les transitions électro-niques S 1 ← S 0 et S 2 ← S 0 du CPC, du CFC et du CCC sont faiblement permises. Par contre, la transition électro-nique S 3 ← S 0 de ces molécules est fortement permise (axe x) et possède une valeur élevée de sa force oscillatrice. D'autre part, pour le CTC, la transition élect...

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Section: Methodsmentioning

confidence: 99%

Spectroscopic and photophysical properties of carbazole-based triads

Belletête¹,

Bédard²,

Bouchard³

et al. 2004

Can. J. Chem.

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“…To develop a general synthesis route of this class of materials, we first focused on the Cadogan reaction. As we recently reported, this reaction give access to a large variety of 2-substituted 25 and 2,7-disubstituted 26 carbazole derivatives which should also be excellent precursors for the synthesis of the desired ladder oligo(p-aniline)s.…”

Section: Synthesis Of Ladder Oligo(p-aniline)s Via the Cadogan Ring-closure Reactionmentioning

confidence: 82%

“…As we can see in Scheme 9, a double Suzuki cross-coupling reaction on compound 5 with 1,4-dibromo-2,5-dinitrobenzene 42 in standard conditions gave 1,4-bis[2-(N-octyl-1,4-dimethylcarbazole)]-2,5-dinitrobenzene (25) in 70% isolated yield. A double Cadogan reaction realized on compound 25 in triethyl phosphite gave a multicomponent mixture, but the targeted oligomer was not obtained.…”

Section: An Approach To the Synthesis Of A Tetramermentioning

confidence: 92%

“…Our first approach was based on carbazole-phenyl precursors bearing the nitro group on the phenyl ring. As shown in Scheme 3, the Suzuki palladium-catalyzed coupling of N-octyl-2(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)carbazole 25 ( 1) to commercially available 1bromo-2-nitrobenzene using a stable Pd II (OAc) 2 in combination with 4 equivalents of triphenylphosphine ligands gave compound 2 in 95% isolated yield. Then, a reductive Cadogan reaction was performed in triethyl phosphite at 160°C to give a mixture of two regioisomers in an 80% isolated yield.…”

Section: Indolocarbazole Derivativesmentioning

confidence: 99%

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Towards the Synthesis of Ladder Oligo(p-aniline)s

Wakim¹,

Leclerc²

2005

Synlett

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“…Leclerc et al [4,5] have reported the spectroscopic and photophysical properties of carbazole-based molecules in solution. The absorption and emission energies of these copolymerized derivatives were correlated with their electronic transitions, as computed by ZINDO calculations performed on optimized HF/6-31G(d) geometries, and first relaxed excited state as obtained by RCIS/6-31G(d) calculations [10,11]. The results demonstrated a good agreement between computed electronic transitions and the optical data.…”

Section: Introductionmentioning

confidence: 85%

Theoretical Studies on the Structural, Electronic and Optical Properties of the New π-conjugated Copolymers Based on Carbazole and Thiophene

et al. 2011

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In the last year, the poly(3,6-carbazole) and derivatives have been synthesized [4,5]. Luminescent materials spanning the entire visible range have been prepared from these polymers [6], and can be used in organic light electronic devices (OLED) [7]. The AbstractThis work reports a theoretical investigation of π-conjugated oligomers constituted by n units (n = 1-4) based on carbazole and ethylenedioxythiophene. The molecular geometry, torsional potential, electronic and optical properties of the oligomers [Cbz-(Edot) n -Cbz] (n = 1-4) are investigated using DFT (B3LYP/3-21G*) calculations. The discussion is focused on the influence of chain length on the properties of these copolymers. The analyses of torsional angles for [Cbz-(Edot) 4 -Cbz] reveal that the structure has a anti-planar conformation. The electronic properties of the molecules, HOMO, LUMO and E g (HOMO-LUMO), are studied using B3LYP functional. The results have been compared with those of thiophene and ethylenedioxythiophene. The lowest excitation energies (E ex ) and the maximal absorption wavelength (λ abs ) are studied using the TD/DFT, ZINDO and CIS methods. The electronic transitions of the absorption spectrum derived by TD/DFT method give useful structural and electronic information for designing novel conducting organic polymer materials. The bridging effect by C=C(CN) 2 on the optoelectronic properties of the (carbazole-thiophene-carbazole) comonomer is investigated.

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Absorption and emission properties of carbazole-based dyads studied from experimental and theoretical investigations

Cited by 23 publications

References 25 publications

Spectroscopic and photophysical properties of carbazole-based triads

Spectroscopic and photophysical properties of carbazole-based triads

Towards the Synthesis of Ladder Oligo(p-aniline)s

Theoretical Studies on the Structural, Electronic and Optical Properties of the New π-conjugated Copolymers Based on Carbazole and Thiophene

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Absorption and emission properties of carbazole-based dyads studied from experimental and theoretical investigations

Cited by 23 publications

References 25 publications

Spectroscopic and photophysical properties of carbazole-based triads

Spectroscopic and photophysical properties of carbazole-based triads

Towards the Synthesis of Ladder Oligo(p-aniline)s

Theoretical Studies on the Structural, Electronic and Optical Properties of the New &pi;-conjugated Copolymers Based on Carbazole and Thiophene

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Theoretical Studies on the Structural, Electronic and Optical Properties of the New π-conjugated Copolymers Based on Carbazole and Thiophene