7-Azaindolyl- and indolyl-functionalized starburst molecules with a 1,3,5-triazine or a benzene core — Syntheses and luminescence

2006 ◽  
Vol 84 (4) ◽  
pp. 477-485 ◽  
Author(s):  
Wei-Hua Huang ◽  
Wen-Li Jia ◽  
Suning Wang

The syntheses of several new 7-azaindolyl-, indolyl-, and 3-methylindolyl-functionalized starburst molecules that contain either a 1,3,5-triazine, a benzene, a 2,4,6-triphenyl-2,4,6-triazine, a 1,3,5-triphenylbenzene, a 2,4,6-tris(biphenyl)-1,3,5-triazine, or a 1,3,5-tris(biphenyl)benzene core have been achieved. The synthetic methods used for these new compounds involve mostly Ullmann condensation and Suzuki coupling reactions. The thermal properties of the new molecules have been found to be highly dependent on the molecular weight and the central core. Glass transition temperatures greater than 150 °C were observed for the large starburst molecules based on the 2,4,6-tris(biphenyl)-1,3,5-triazine or the 1,3,5-tris(biphenyl)benzene core. The new starburst molecules are luminescent in the violet-blue region in solution and in the solid state. The emission energy and the quantum efficiency were found to be highly dependent on the central core and the functional group. In general, the triazine-based molecules were found to have a smaller HOMO–LUMO energy gap than the benzene-based analogues. The triphenyltriazine- or triphenylbenzene-based molecules were found to display a higher emission quantum efficiency than the large tris(biphenyl)triazine- or tris(biphenyl)benzene-based molecules.Key words: 7-azaindolyl, indolyl derivative, triazine and benzene cores, starburst molecule, blue luminescence.

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7309
Author(s):  
Gulraiz Ahmad ◽  
Nasir Rasool ◽  
Adeel Mubarik ◽  
Ameer Fawad Zahoor ◽  
Muhammad Ali Hashmi ◽  
...  

Synthesis of 5-aryl-N-(pyrazin-2-yl)thiophene-2-carboxamides (4a–4n) by a Suzuki cross-coupling reaction of 5-bromo-N-(pyrazin-2-yl)thiophene-2-carboxamide (3) with various aryl/heteroaryl boronic acids/pinacol esters was observed in this article. The intermediate compound 3 was prepared by condensation of pyrazin-2-amine (1) with 5-bromothiophene-2-carboxylic acid (2) mediated by TiCl4. The target pyrazine analogs (4a–4n) were confirmed by NMR and mass spectrometry. In DFT calculation of target molecules, several reactivity parameters like FMOs (EHOMO, ELUMO), HOMO–LUMO energy gap, electron affinity (A), ionization energy (I), electrophilicity index (ω), chemical softness (σ) and chemical hardness (η) were considered and discussed. Effect of various substituents was observed on values of the HOMO–LUMO energy gap and hyperpolarizability. The p-electronic delocalization extended over pyrazine, benzene and thiophene was examined in studying the NLO behavior. The chemical shifts of 1H NMR of all the synthesized compounds 4a–4n were calculated and compared with the experimental values.


Author(s):  
Jihyeon Kim ◽  
Heechan Kim ◽  
Sechan Lee ◽  
Giyun Kwon ◽  
Taewon Kang ◽  
...  

A new bipolar-type redox-active organic material with a wide HOMO–LUMO energy gap is designed though the ‘p–n fusion’ strategy.


2006 ◽  
Vol 05 (03) ◽  
pp. 595-608 ◽  
Author(s):  
KRIENGSAK SRIWICHITKAMOL ◽  
SONGWUT SURAMITR ◽  
POTJAMAN POOLMEE ◽  
SUPA HANNONGBUA

The structural and energetic properties of polyfluorene and its derivatives were investigated, using quantum chemical calculations. Conformational analysis of bifluorene was performed by using ab initio (HF/6-31G* and MP2/6-31G*) and density functional theory (B3LYP/6-31G*) calculations. The results showed that the local energy minimum of bifluorene lies between the coplanar and perpendicular conformation, and the B3LYP/6-31G* calculations led to the overestimation of the stability of the planar pi systems. The HOMO-LUMO energy differences of fluorene oligomers and its derivatives — 9,9-dihexylfluorene (DHPF), 9,9-dioctylfluorene (PFO), and bis(2-ethylhexyl)fluorene (BEHPF) — were calculated at the B3LYP/6-31G* level. Energy gaps and effective conjugation lengths of the corresponding polymers were obtained by extrapolating HOMO-LUMO energy differences and the lowest excitation energies to infinite chain length. The lowest excitation energies and the maximum absorption wavelength of polyfluorene were also performed, employing the time-dependent density functional theory (TDDFT) and ZINDO methods. The extrapolations, based on TDDFT and ZINDO calculations, agree well with experimental results. These theoretical methods can be useful for the design of new polymeric structures with a reducing energy gap.


2019 ◽  
Vol 75 (7) ◽  
pp. 1079-1083
Author(s):  
Tanwawan Duangthongyou ◽  
Ramida Rattanakam ◽  
Kittipong Chainok ◽  
Songwut Suramitr ◽  
Thawatchai Tuntulani ◽  
...  

The title compound, C31H30N2S2O6, possesses crystallographically imposed twofold symmetry with the two C atoms of the central benzene ring and the C atom of its methyl substituent lying on the twofold rotation axis. The two dansyl groups are twisted away from the plane of methylphenyl bridging unit in opposite directions. The three-dimensional arrangement in the crystal is mainly stabilized by weak hydrogen bonds between the sulfonyl oxygen atoms and the hydrogen atoms from the N-methyl groups. Stacking of the dansyl group is not observed. From the DFT calculations, the HOMO–LUMO energy gap was found to be 2.99 eV and indicates n→π* and π→π* transitions within the molecule.


2021 ◽  
Vol 4 (4) ◽  
pp. 236-251
Author(s):  
A. S. Gidado ◽  
L. S. Taura ◽  
A. Musa

Pyrene (C16H10) is an organic semiconductor which has wide applications in the field of organic electronics suitable for the development of organic light emitting diodes (OLED) and organic photovoltaic cells (OPV). In this work, Density Functional Theory (DFT) using Becke’s three and Lee Yang Parr (B3LYP) functional with basis set 6-311++G(d, p) implemented in Gaussian 03 package was  used to compute total energy, bond parameters, HOMO-LUMO energy gap, electron affinity, ionization potential, chemical reactivity descriptors, dipole moment, isotropic polarizability (α), anisotropy of polarizability ( Δ∝) total first order hyper-polarizability () and second order hyperpolarizability (). The molecules used are pyrene, 1-chloropyrene and 4-chloropyrene  in gas phase and in five different solvents: benzene, chloroform, acetone, DMSO and water. The results obtained show that solvents and chlorination actually influenced the properties of the molecules. The isolated pyrene in acetone has the largest value of HOMO-LUMO energy gap of and is a bit closer to a previously reported experimental value of  and hence is the most stable. Thus, the pyrene molecule has more kinetic stability and can be described as low reactive molecule. The calculated dipole moments are in the order of 4-chloropyrene (1.7645 D) < 1-chloropyrene (1.9663 D) in gas phase. The anisotropy of polarizability ( for pyrene and its derivatives were found to increase with increasing polarity of the solvents.  In a nutshell, the molecules will be promising for organic optoelectronic devices based on their computed properties as reported by this work.


2020 ◽  
Vol 86 (1) ◽  
pp. 770-781
Author(s):  
Akihiro Shimizu ◽  
Yu Ishizaki ◽  
Shun Horiuchi ◽  
Takashi Hirose ◽  
Kenji Matsuda ◽  
...  
Keyword(s):  

2018 ◽  
Vol 20 (28) ◽  
pp. 19007-19016 ◽  
Author(s):  
Manoj Majumder ◽  
Anirban Misra

The zwitterionic donor–acceptor group significantly reduces the HOMO–LUMO energy gap resulting in an enormous increase in the first hyperpolarizability values.


2019 ◽  
Vol 1195 ◽  
pp. 620-631 ◽  
Author(s):  
Sanaa AlAbbad ◽  
Tova Sardot ◽  
Oliko Lekashvili ◽  
Daniel Decato ◽  
Francesco Lelj ◽  
...  

2001 ◽  
Vol 12 (2) ◽  
pp. 200-205 ◽  
Author(s):  
William J. Mitchell ◽  
Christophe Pena ◽  
Paul L. Burn
Keyword(s):  

2019 ◽  
Vol 4 (2) ◽  
pp. 70-76
Author(s):  
Sandhya Chhakra ◽  
A. Mukherjee ◽  
H.L. Singh ◽  
Suresh Singh Chauhan

An efficient synthesis of novel 2,3,4-trisubstituted 1,5-benzothiazepines (4a-e) incorporating the sulfonyl group is described. Compound (4a-e) was synthesized by the reaction of 3-(1,4-dioxane-6-sulfonyl)-2,4-dimethyl/4-methyl-2-phenyl/2,4-diphenyl/2-ethoxy-4-methyl/2,4-diethoxy propane-1,3-dione (3ae) with 2-aminobenzenethiol with ZnOnanoparticles/pyridine. Formation of compound (3a-e) was achieved by the reaction of 1,4-dioxane-6-sulfonyl chloride (1) with 2,4-dimethyl/4-methyl-2-phenyl/2,4-diphenyl/2-ethoxy-4-methyl/2,4-diethoxy propane-1,3-dione (2a-e). The benzothiazepines (4a-e) obtained were purified by column chromatography (benzene: CHCl3, 40:60, 30:70, 20:80, 10:90) and crystallized from methanol. The purity of the compounds was checked by TLC using (CHCl3: CH3OH, 9:1) as the mobile phase. The structure of the compounds has been established by elemental, IR, 1H NMR, 13C NMR and Mass spectral analyses. Frontier molecular orbitals of the title compounds have been studied in the ground state speculatively. The reactivity of a molecule using diverse descriptors such as softness, electrophilicity, electronegativity, HOMO-LUMO energy gap is calculated additionally discussed.


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