نتایج جستجو برای: carbazole chromophores

تعداد نتایج: 4441  

Journal: :The Journal of antibiotics 1989
J Golik T W Doyle B Krishnan G Dubay J A Matson

The chemical structures of AT2433-A1 (2), AT2433-A2 (3), AT2433-B1 (4) and AT2433-B2 (5) were elucidated by degradation and spectroscopic studies. Compounds 2-5 are disaccharides closely related to rebeccamycin. The aglycone in 2 and 3 was determined to be 6-N-methyl-11-chloro-5H-indolo[2,3-a]pyrolo[3,4-c]carbazole and in 4 and 5 it was determined to be 6-N-methyl-5H-indolo[2,3-a]pyrolo[3,4-c]c...

2015
Abhishek Tandon Vikram Kumar

The leaf extract of Murraya koenigii were assessed for In vitro Anti Inflammatory activity by HRBC membrane stabilization method and Denaturation of protein inhibition method. The presence of flavanoids and carbazole alkaloids has been reported earlier in M.koenigii. Since the flavanoids and carbazole alkaloids have remarkable anti-inflammatory activity, so the present work aims at evaluating t...

2015
Ryan L. Lehane James A. Golen Arnold L. Rheingold David R. Manke

In the title compound, C16H13NO4, the carbazole ring system is almost planar with non-H atoms possessing a mean deviation from planarity of 0.037 Å. The two ester groups are orientated trans to one another and tilted slightly from the mean plane of the carbazole ring system, making dihedral angles of 8.12 (6) and 8.21 (5)°. In the crystal, mol-ecules are linked by pairs of N-H⋯O hydrogen bonds ...

2014
P. Narayanan K. Sethusankar Velu Saravanan Arasambattu K. Mohanakrishnan

In the title compound, C26H18Cl2N2O5S, the carbazole ring system is essentially planar with a maximum deviation of 0.0498 (16) Å for the N atom. The carbazole ring system is almost orthogonal to the phenyl-sulfonyl and di-chloro-substituted nitro-phenyl rings, making dihedral angles of 84.23 (7) and 85.46 (12)°, respectively. The mol-ecular structure features intra-molecular C-H⋯O inter-actions...

2016
Eva Jürgens Kai N. Buys Anna-Theresa Schmidt Samantha K. Furfari Marcus L. Cole Michael Moser Frank Rominger Doris Kunz

Herein we report the optimised synthesis of a versatile bis(imidazole)carbazole framework 4, a precursor to our previously reported C–N–C bis(NHC) pincer ligand, bimca. We have also used 4 as a basis for constructing a library of fully characterised bis(imidazolium) salt pre-ligands which vary the steric and electronic parameters of the subsequently formed NHC moieties. Lithium bis(NHC)carbazol...

2017
Adam D. Martin Jonathan P. Wojciechowski Andrew B. Robinson Celine Heu Christopher J. Garvey Julian Ratcliffe Lynne J. Waddington James Gardiner Pall Thordarson

Using small angle neutron scattering (SANS), it is shown that the existence of pre-assembled structures at high pH for a capped diphenylalanine hydrogel is controlled by the selection of N-terminal heterocyclic capping group, namely indole or carbazole. At high pH, changing from a somewhat hydrophilic indole capping group to a more hydrophobic carbazole capping group results in a shift from a h...

Journal: :Organic & biomolecular chemistry 2015
Chihiro Maeda Kosuke Kurihara Motoki Masuda Naoki Yoshioka

The synthesis and photophysical properties of cyano and ethynyl substituted carbazole-based porphyrins were investigated. The introduction of ethynyl groups induced red shifts, while that of cyano groups induced blue shifts of their absorption bands, which was supported by MO calculations. Ethylenedioxy-appended porphyrins were also prepared via a coupling reaction. The conjugated and electroni...

Journal: :Journal of biological physics 1999
N L Vekshin

An improved model of the screening effect is suggested. Mutual ≪shielding≫ of chromophores from light due to competition for the incident photon can take place in molecular aggregates and macromolecules. From a common point of view, it could be interpreted as in ≪interaction≫ of the absorption dipol moment transitions. Screening leads to a decrease in the extinction coefficient. The largest dec...

2017
Jim Simpson Shaaban K. Mohamed Talaat I. El-Emary Mustafa R. Albayati

The title compound, C16H13N3OS, comprises an oxa-diazo-lethione ring bound to the N atom of an almost planar carbazole ring system (r.m.s. deviation = 0.0088 Å) through an ethyl-ene chain. The oxa-diazole ring is inclined to the the carbazole ring system by 40.71 (6)°. In the crystal, N-H⋯O, N-H⋯S, C-H⋯N and C-H⋯S hydrogen bonds combine with C-H⋯π(ring) and π-π contacts to stack the mol-ecules ...

Journal: :Molecules 2013
Rafael Bautista Pablo A Montoya Araceli Rebollar Eleuterio Burgueño Joaquín Tamariz

A palladium-catalyzed synthesis of the carbazole framework is described, including the preparation of 2-, 5-, and 7-oxygenated natural and unnatural carbazole alkaloids. A series of N-arylcyclohexane enaminones, generated by condensation of cyclohexane-1,3-dione with diverse anilines, were aromatized by a Pd(0)-catalyzed thermal treatment to afford the corresponding diarylamines. The latter wer...

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