1484-04-4Relevant articles and documents
A short route to heteroarylcarbazoles: Synthesis of new pyrazolylcarbazoles and carbazolylquinolines
Nagarajan, Rajagopal,Perumal, Paramasivan T.
, p. 1269 - 1273 (2004)
A short synthesis of pyrazolylcarbazoles from 9-alkyl-carbazoles in three steps is reported. The acetylcarbazoles prepared by the acetylation of carbazoles with acetic anhydride catalyzed by BiCl3 were converted into chloroaldehydes with Vilsmeier reagent. Condensation of chloroaldehydes with hydrazine followed by cyclization yield the pyrazolylcarbazoles. Carbazolyl chalcones were prepared by the condensation of carbazole-3-aldehyde with o-aminoacetophenone and cyclized to carbazolylquinolone using several catalysts. Cyclization of carbazolyl chalcones with the Vilsmeier reagent yields a mixture of carbazolylquinoline carbaldehydes.
A New and Facile Method for the Synthesis of Nitrocarbazoles by Urea Nitrate
Nagarajan, Rajagopal,Muralidharan,Perumal, Paramasivan T.
, p. 1259 - 1264 (2004)
Urea nitrate in acetic acid is found to be an effective and mild nitrating agent for the preparation of mono nitrocarbazoles.
A facile method for the synthesis of acetylcarbazoles and carbazole aldehydes
Nagarajan, Rajagopal,Perumal, Paramasivan T.
, p. 2127 - 2133 (2004)
Acetylation of 9-alkylcarbazoles with acetic anhydride catalyzed by PPh3. HClO4 was reported to give acetylcarbazoles. Carbazole aldehydes were easily synthesized by the Vilsmeier reaction of 9-alkylcarbazoles under microwave condition in good yields.
Influence of thiophene spacer and auxiliary acceptor on the optical properties of 4-(Diethylamino)-2-hydroxybenzaldehyde based D-π-A-π-D Colorants with N-alkyl donors: Experimental, DFT and Z-scan study
Raikwar, Manish M.,Patil, Dinesh S.,Mathew, Elizabeth,Varghese, Manu,Joe, Issac H.,Sekar, Nagaiyan
, p. 45 - 58 (2019)
We report here design and synthesis of four new D-π-A-π-D type dyes (4 and 5) with triphenylamine/N-ethyl carbazole as fixed rotor/donor and N, N-diethyl amine as a secondary donor having dicyanovinylene as a common acceptor. The Influence of π-linker (thiophene) along with an auxillary cyano group on the nonlinear and linear optical properties is investigated. Molecules with thiophene spacer (4b and 5b) exhibit progressive variation in their absorption and emission profiles reflecting the effect of π-linker, compared to those devoid of thiophene spacer (4a and 5a). The dyes display solvent dependent emission [e.g. 4b (toluene = 689 nm) and 5b (DMSO = 795 nm)] suggesting a more polarized photo-excited state arising as a result of enhanced intramolecular charge transfer in the excited state. The solvatochromic nature is supportive of a general solvent effect, which is confirmed by solvent polarity plots (Weller's and Rettig's plot). The trends in the optical properties were also validated by time dependent density functional theory computations which further reveals charge transfer (from secondary donor to acceptor) for the long wavelength absorption. Dye with the highest charge transfer dipole moment relatively has the maximum two-photon absorption cross-section area (4b = 246–399 GM) which was established using theoretical two-level model. Non-linear optical properties were investigated using solvatochromic two-level model and computationally using global and range separated hybrid functionals. The dyes show high first-order hyperpolarizability (β0) in the range of 191–1162 × 10?30 e.s.u. and second-order hyperpolarizability (γ0) in the range of 491–6,704 × 10?36 e.s.u. Z-scan results show 4a (3.79 × 10?13 e.s.u.) possesses a higher value of third order nonlinear susceptibility in DMSO. Thus, the dyes can be considered as promising candidates for NLO application in material science.
Fluorescent probe of reversible sulfur dioxide/sulphurous acid (hydrogen) salt
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Paragraph 0025; 0026, (2018/06/16)
The invention provides a fluorescent probe of reversible sulfur dioxide/sulphurous acid (hydrogen) salt, with the chemical name of 7-diethylin-2-(9-ethyl-9H-carbazole-3) benzo iso-pyran oxonium ion. The fluorescent probe can detect sulfur dioxide/sulphurous acid (hydrogen) salt in a solution, cells, tissues or a living body, wherein the living body includes fish, mice, rat, guinea pig and rabbit;and reversibility is realized by formaldehyde. The fluorescent probe is simple in synthesis steps, easily available in material, high in yield and suitable for industrial application.
