Merocyanine Dyes with Extended Polymethine Chains by Simple Two-Step Condensation Sequence

Synthesis ◽  
2020 ◽  
Vol 53 (02) ◽  
pp. 318-325
Author(s):  
Frank Würthner ◽  
Alhama Arjona-Esteban ◽  
Anja Rausch ◽  
Myroslav O. Vysotsky
Keyword(s):  
Synthetic Method ◽  
Double Bonds ◽  
Absorption Bands ◽  
Condensation Reactions ◽  
Intense Absorption ◽  
Merocyanine Dyes

We describe a synthetic method for the synthesis of merocyanine dyes containing a bridge with three conjugated double bonds. This method consists of two successive condensation reactions. The first one is made between CH-acidic indane-1,3-dione acceptor units and an appropriate ketone (here acetone or hexan-2-one). The extended acceptor thus obtained is condensed with an aldehyde in the next step. The dyes show high tinctorial strength due to intense absorption bands at wavelengths between 500 and 750 nm.

scholarly journals Functionalized BODIPY Derivatives as Potential Fluorescent Labels

Proceedings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 36
Author(s):  
Raquel C. R. Gonçalves ◽  
Mariana B. Nogueira ◽  
Susana P. G. Costa ◽  
M. Manuela M. Raposo
Keyword(s):  
Boron Trifluoride ◽  
Spectroscopic Techniques ◽  
Fluorescent Labels ◽  
Absorption Bands ◽  
Boron Trifluoride Diethyl Etherate ◽  
Photophysical Study ◽  
Intense Absorption ◽  
Emission Studies

4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivatives 1 and 2 were obtained with 16% and 33% yield by a two-step reaction: condensation of a pyrrole with the corresponding aldehyde followed by oxidation with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in the presence of boron trifluoride diethyl etherate (BF3OEt2). The two compounds were characterized by the usual spectroscopic techniques and a detailed photophysical study was undertaken. The compounds exhibited intense absorption bands at 502 nm and 497 nm, respectively. Emission studies of the compounds 1 and 2 showed emission bands with maximum wavelength at 518 nm and 519 nm, respectively.

Phthalocyanines as photodynamic agents for the inactivation of microbial pathogens

2006 ◽  
Vol 10 (03) ◽  
pp. 147-159 ◽  
Author(s):  
Donata Dei ◽  
Giacomo Chiti ◽  
Maria P. De Filippis ◽  
Lia Fantetti ◽  
Francesco Giuliani ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Physicochemical Properties ◽  
Cell Survival ◽  
Chemical Structure ◽  
Microbial Pathogens ◽  
High Quantum Yield ◽  
Absorption Bands ◽  
E Coli ◽  
Log Reduction ◽  
Intense Absorption

A variety of 1,8(11),15(18),22(25)- and 2,9(10),16(17),23(24)-tetra-substituted and 2,3,9,10,16,17,23,24-octa-susbtituted Zn (II) phthalocyanines, bearing dialkylaminophenoxy and trialkylammoniumphenoxy groups, have been synthetized, characterized and tested as photosensitizers against S. aureus, E. coli and C. albicans. All phthalocyanines exhibited intense absorption bands in the phototherapeutically useful 670-700 nm region, with a molar extinction coefficient of the order of 105 M-1.cm-1. All derivatives bearing positive charges showed a good photosensitizing efficiency (causing a greater than 4 log reduction in cell survival), as well as a high quantum yield for generation of singlet oxygen. Variations of the chemical structure appeared to strongly affect both the physicochemical properties and the phototoxic activities against microorganisms.

Characteristic Infrared Absorption Bands for Diels—Alder Quinone Adducts and Derivatives

1968 ◽  
Vol 22 (1) ◽  
pp. 54-57 ◽  
Author(s):  
G. E. Pollard
Keyword(s):  
Infrared Spectra ◽  
Infrared Absorption ◽  
Diels Alder ◽  
Double Bonds ◽  
Empirical Correlations ◽  
Absorption Bands ◽  
Infrared Absorption Bands

Extension of established correlations for carbonyl and carbon—carbon double bonds have been evolved for some Diels—Alder quinone adducts and derivatives. Some empirical correlations for novel nortricyclenic derivatives are discussed. These compounds have four possible stereoisomers and their infrared spectra provide a ready method of differentiation.

Complexes of alkyl and aryl cyanides. Part VI. The vibrational spectra of MX2•2RCN, where M = Pd or Pt, X = Cl or Br, and R = Me or Ph, and the assignment of the metal–nitrogen stretching frequency

1968 ◽  
Vol 46 (14) ◽  
pp. 2347-2352 ◽  
Author(s):  
R. A. Walton
Keyword(s):  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Metal Halide ◽  
Careful Examination ◽  
Absorption Bands ◽  
Intense Absorption ◽  
Nitrogen Bonds ◽  
Cis And Trans ◽  
First Time

A careful examination of the Raman and infrared spectra of the crystalline planar complexes cis-and trans-MX2•2RCN, where M = Pd or Pt, X = Cl or Br, and R = Me or Ph, reveals intense absorption bands in the 125–80 cm−1 region which can be assigned to modes involving stretching of the metal–nitrogen bonds. Alternative assignments for v(M—N) are also discussed. These results are compared with those for other metal halide – RCN systems. The complexes trans-PtBr2•2RCN are described for the first time.

Interpretation of experimental IR spectra of (z)-4-(2- (acryloyloxy)ethoxy)-4-oxobut-2-enoic acid and its polymers

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Chen Song ◽  
Xiaoyu Li
Keyword(s):  
Ir Spectra ◽  
Density Functional ◽  
Solid Phase ◽  
Enoic Acid ◽  
Field Calculation ◽  
Double Bonds ◽  
Absorption Bands ◽  
Experimental Ir ◽  
Functional Theory ◽  
Full Structure

AbstractThe solid phase FTIR spectra of (z)-4-(2-(acryloyloxy)ethoxy)-4-oxobut- 2-enoic acid (cis-AEOEA) and its polymers have been recorded in the regions 3500~500 cm-1, respectively. The IR spectra of cis-AEOEA was interpreted with the aid of normal coordinated analysis following full structure optimization and force field calculation based on density functional theory (DFT). Standard scaling factor was used to afford better correspondence between the calculated and experimental wavenumbers for the separation and unambiguous identification of observed IR spectra of cis-AEOEA, especially for C=C double bonds. The characteristic absorption bands of C=C are used for identifying the kind of C=C double bonds in cis-AEOEA’s polymers.

scholarly journals CHARACTERISTICS OF EXOPOLYSACCHARIDE LACTOBACILLUS CASEI CO1 AND ITS ANTIOXIDANT ACTIVITY

2019 ◽  
Vol 49 (06) ◽  
pp. 51-56
Author(s):  
Nilufar Elova
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Ir Spectrum ◽  
Lactobacillus Casei ◽  
Local Strain ◽  
Monosaccharide Composition ◽  
Absorption Bands ◽  
Intense Absorption

In this work presents the results of studies on the ability to synthesize exopolysaccharides (EPS) by a local strain of Lactobacillus casei CO1, isolated from the epiphytic microflora of lilac flowers. In the IR spectrum of EPS, intense absorption bands were found, generally characteristic of the carbohydrate class. The monosaccharide composition was established and the molecular weight of the exopolysaccharide was determined. Revealed % RSA of EPS in the system of DPPH (diphenylpycrylhydrazil).

Infrared Microsampling by Diffuse Reflectance Fourier Transform Spectrometry

1980 ◽  
Vol 34 (5) ◽  
pp. 533-539 ◽  
Author(s):  
Michael P. Fuller ◽  
Peter R. Griffiths
Keyword(s):  
Fourier Transform ◽  
Thin Layer ◽  
Diffuse Reflectance ◽  
Absorption Bands ◽  
Fourier Transform Spectrometry ◽  
Increased Sensitivity ◽  
Intense Absorption ◽  
Diffuse Reflectance Infrared ◽  
Layer Chromatography

It is shown that diffuse reflectance techniques enable increased sensitivity to be obtained for infrared microsampling compared with the use of KBr micropellets. When nonabsorbing matrices, such as KCl, are used, detection limits of less than 10 ng of samples are observed. Samples absorbed on graphitized substrates, which have a fairly strong general absorption but few intense absorption bands, may also be studied but at somewhat reduced sensitivity. Diffuse reflectance infrared Fourier transform spectrometry does not appear to be particularly useful for studying adsorbates on silica gel, which is not only a strong infrared absorber but also has a surface which is so active that small changes in the surface structure can change the spectrum significantly. Extraction of sample spots from thin layer chromatography plates followed by deposition onto KCl yields much better results than in situ measurements.

scholarly journals One-pot three-component synthesis and photophysical characteristics of novel triene merocyanines

2014 ◽  
Vol 10 ◽  
pp. 599-612 ◽  
Author(s):  
Christian Muschelknautz ◽  
Robin Visse ◽  
Jan Nordmann ◽  
Thomas J J Müller
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Sonogashira Coupling ◽  
Absorption Bands ◽  
One Pot ◽  
Red Emission ◽  
Long Wavelength ◽  
Dft Computations ◽  
Td Dft ◽  
Intense Absorption

Novel triene merocyanines, i.e. 1-styryleth-2-enylidene and 4-(1,3,3-trimethylindolin-2-ylidene)but-2-en-1-ylideneindolones are obtained in good to excellent yields in a consecutive three-component insertion Sonogashira coupling–addition sequence. The selectivity of either series is remarkable and has its origin in the stepwise character of the terminal addition step as shown by extensive computations on the DFT level. All merocyanines display intense absorption bands in solution and the film spectra indicate J-aggregation. While 1-styryleth-2-enylideneindolones show an intense deep red emission in films, 4-(1,3,3-trimethylindolin-2-ylidene)but-2-en-1-ylideneindolones are essentially nonemissive in films or in the solid state. TD-DFT computations rationalize the charge-transfer nature of the characteristic broad long-wavelength absorptions bands.

scholarly journals Characterization and Evaluation of the Efficiency of TiO2/Zinc Phthalocyanine Nanocomposites as Photocatalysts for Wastewater Treatment Using Solar Irradiation

2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
Antonio E. H. Machado ◽  
Marcela D. França ◽  
Valdemir Velani ◽  
Gabriel A. Magnino ◽  
Hosana M. M. Velani ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Diffuse Reflectance ◽  
Near Infrared ◽  
Visible Spectrum ◽  
Zinc Phthalocyanine ◽  
Solar Irradiation ◽  
Absorption Bands ◽  
Intense Absorption ◽  
Spectrum Region

This work reports the characterization of composites prepared by the association between zinc phthalocyanine (ZnPc) and titanium dioxide. These composites are better photocatalysts for wastewater decontamination mediated by solar radiation than pureTiO2, performance that remains even when reused. The UV-Vis diffuse reflectance absorption spectra show for these composites two intense absorption bands. The first covers the ultraviolet and part of the visible spectrum region until 460 nm (2.7 eV), whereas the second, nonstructured, goes from 475 nm until the near infrared with an absorption peak at 683 nm attributed to the Q band of ZnPc. The production of additionale−/h+pairs by these aggregates when photoexcited, their capability to act as charge carrier, the thickness and regularity of their distribution on theTiO2surface seem to be important parameters for the performance observed for these composites.

Stabilization of mixed valencies in Cu, Zn-based oxides

2005 ◽  
Vol 891 ◽  
Author(s):  
Anne Le Nestour ◽  
Manuel Gaudon ◽  
Mona Tréguer-Delapierre ◽  
Ronn Andriessen ◽  
Alain Demourgues
Keyword(s):  
Solid Solution ◽  
Solid State ◽  
Solid State Synthesis ◽  
Zinc Aluminate ◽  
Absorption Bands ◽  
Absorption Properties ◽  
Nir Absorption ◽  
Uv Visible ◽  
Intense Absorption ◽  
Copper Cations

ABSTRACTCu and Zn-based oxides have been developed for the last decades because of their remarkable electronic properties and their relevant UV-Visible-NIR absorption properties. Cu in oxides can adopt various oxidation states (+I, +II, +III) stabilized in various environments (h, Td, D4h, C4v, D2h, Oh). Divalent copper cations can occupy Td or Oh sites in zinc aluminate spinel network. Solid state routes lead to homogeneous phases with Zn1−xCuxAl2O4 compositions. Depending on the inversion rate in the spinel matrix, various absorption bands have been identified in the UV-Visible-CNIR spectrum. The synthesis of the zinc-aluminate spinel solid solution Zn1−xCuxAl2O4 by an esterification route led to monocrystalline nanosized oxides. Two intense absorption bands at 300 and 500 nm can be attributed to charge transfer phenomena between oxygen and Cu2+ cations in tetrahedral and octahedral coordinations. Two other less intense absorption bands centred at 800 nm and 1500 nm are also appearing when the copper rate in the spinel increases but their relative intensity are not in good agreement with those observed in the case of the solid-state synthesis. In the case of the esterification route, the absorption band at 800 nm is much more intense than in the case of the solid-state synthesis. It can only be explained either by a deviation to the centrosymmetric character of octahedral sites or by the occurence of a non negligible amount of monovalent copper cations which give electronic transitions in this energy range. A magnetic study correlated to EPR measurements confirms the occurence of a mixed valence state for copper cations in the solid solution Zn1−xCuxAl2O4. EPR spectra at T=4K show for the small concentration of Cu2+ (x<0.10) a strong anisotropic signal due to the presence of Cu2+ ions in a distorted octahedral symmetry (gx=2.07, gy= 2.15 gz=2.23). Moreover the hyperfine structure, identified on EPR spectra tend to disappear as the compounds are annealed under air because the content of paramagnetic centers Cu2+ (3d9) as well as their interactions become significant. Furthermore, the color changes drastically with the Cu+ (3d10) content. Finally the structural features and UV-Visible-NIR absorption properties of copper-zinc aluminates will be discussed and compared to Cu-doped ZnO.

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