Quinoline-annulated chlorins and chlorin-analogs

2016 ◽  
Vol 20 (01n04) ◽  
pp. 265-273 ◽  
Author(s):  
Joshua Akhigbe ◽  
Mengxi Yang ◽  
Michael Luciano ◽  
Christian Brückner
Keyword(s):  
Absorption Spectra ◽  
Functional Group ◽  
Bathochromic Shift ◽  
Red Shift ◽  
Simple Strategy

The OsO4-mediated dihydroxylation of quinoline-annulated porphyrin generates a quinoline-annulated dihydroxychlorin in a regioselective fashion. Its dihydroxypyrroline moiety, located at the opposite of the annulated pyrrole, is susceptible to the same functional group interconversions we previously demonstrated for non-annulated dihydroxychlorins: oxidations to the corresponding dione, lactone, and dialkoxymorpholine derivatives. The quinoline-annulated chlorin and derivatives are all characterized by absorption spectra that are much broadened and between 130 and 220 nm red-shifted compared to their non-annulated analogs. Absorbance maxima in the NIR up to well above 800 nm were recorded. We attribute the bathochromic shift to their extended [Formula: see text]-systems and inferred non-planarity, highlighting that quinoline-annulation is a particularly effective and simple strategy to red-shift the absorption spectra of chlorins and chlorin analogs.

Absorption Spectra of Substituted 2-Phenylindan-1,3-Dion-2-YL Radicals in Solution

1983 ◽  
Vol 38 (12) ◽  
pp. 1337-1341
Author(s):  
J. Zechner ◽  
N. Getoff ◽  
I. Timtcheva ◽  
F. Fratev ◽  
St. Minchef
Keyword(s):  
Free Energy ◽  
Absorption Spectra ◽  
Flash Photolysis ◽  
Bathochromic Shift ◽  
Substitution Effects ◽  
Linear Free Energy Relationship ◽  
Linear Free Energy

Abstract Flash photolysis of a series of 2-phenylindandione-1,3 derivatives substituted in the 4′ position results in both the formation of stable benzylidenephthalides and of phenylindan-1,3-dion-2-yl radicals. The u. v. absorption maxima of these radicals are dependent on the solvent and show a bathochromic shift upon substitution. These substitution effects were correlated by means of a linear free energy relationship. Attempts were made to draw conclusions concerning the changes in the gap of the states involved and their curvature due to substitution.

Bathochromic shift in absorption spectra of conjugated polymer nanoparticles with displacement along backbones

2015 ◽  
Vol 23 (6) ◽  
pp. 574-577 ◽  
Author(s):  
Dongkyun Seo ◽  
Jonghyup Park ◽  
Tae Joo Shin ◽  
Pil J. Yoo ◽  
Juhyun Park ◽  
...  
Keyword(s):  
Absorption Spectra ◽  
Conjugated Polymer ◽  
Bathochromic Shift ◽  
Polymer Nanoparticles ◽  
Conjugated Polymer Nanoparticles

Halogen-Substitution Effect on the Optical Absorption Bands of Uracil*

1974 ◽  
Vol 29 (9-10) ◽  
pp. 493-495 ◽  
Author(s):  
Wolfgang Lohmann
Keyword(s):  
Optical Absorption ◽  
Linear Function ◽  
Absorption Spectra ◽  
Electron Affinity ◽  
Substitution Effect ◽  
Ultraviolet Absorption ◽  
Red Shift ◽  
Electron Affinities ◽  
Absorption Bands ◽  
Extinction Coefficients

Abstract The ultraviolet absorption spectra of uracil and its 5-halogenated derivatives have been in ­ vestigated in regard to the electron attracting properties of the substituents. It could be shown that the position of the two absorption bands is proportional to the inverse of the electronegativity; the extinction coefficients are a linear function of the electron affinities. In this way, the red shift obtained upon substitution with halogens can be explained. Also, the decrease in absorbance of the absorption bands at λ > 250 nm, occuring concomitant­ ly, is understandable. The increase in absorbance with increasing electron affinity, as observed in the case of the absorption bands at λ < 250 nm, might question the assumption that this band is due to a higher pi -pi* excitation

Functional group and substituent effects, both steric and electronic, upon the ultraviolet absorption spectra of some N-alkyl- and N,N-dialkyl-derivatives of some cinnamamides and benzalcyanoacetamides

1969 ◽  
Vol 47 (17) ◽  
pp. 3278-3280 ◽  
Author(s):  
A. D. Delaney ◽  
D. J. Currie ◽  
H. L. Holmes
Keyword(s):  
Hydrogen Atom ◽  
Absorption Spectra ◽  
Functional Group ◽  
Substituent Effects ◽  
Ultraviolet Absorption ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Derivatives Of

Conjugative and steric constants for N-substituted carboxyamide groups have been derived which allow the calculation of the long wavelength absorption maxima of N-alkyl- and N,N-dialkyl-derivatives of cinnamamide and benzalcyanoacetamide. Deviations between calculated and observed values indicate that there may be steric interference between bulky N,N-dialkylcarboxyamide groups and the benzylic hydrogen atom.

Red-shift of the excitonic level in two beam absorption spectra of GaSe

1988 ◽  
Vol 38 (4) ◽  
pp. 627-631 ◽  
Author(s):  
L Pavesi ◽  
V Capozzi ◽  
J L Staehli
Keyword(s):  
Absorption Spectra ◽  
Red Shift

Enhanced Photocatalytic Performance of Iodine Doped Bi2WO6 Nanostructures under Visible-Light Irradiation

2013 ◽  
Vol 423-426 ◽  
pp. 163-166 ◽  
Author(s):  
Bao Wei Cao ◽  
Yun Hua Xu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Hydrothermal Method ◽  
Absorption Spectra ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Photocatalytic Performance ◽  
Red Shift ◽  
Light Irradiation ◽  
Photocatalytic Activities

Bi2WO6 doped with iodine ions were synthesized using hydrothermal method and their photocatalytic activities to degrade Rhodamine B (RhB) under visible-light was investigated. The successful incorporation of I ions in Bi2WO6 was proved by XRD and XPS. UV-vis absorption spectra results show that I ion was successfully doped into Bi2WO6 and a red shift for I-doped Bi2WO6 appeared when compared to pure Bi2WO6. The photocatalytic activities of the photocatalysts were evaluated by the decolorization of RhB under visible-light irradiation. The results showed that the photocatalytic activity of I-doped Bi2WO6 was much higher than the undoped Bi2WO6.

Bathochromic shift of the Q-bands of octakis(p-t-butylbenzyloxy)phthalocyanines with magnesium(II), nickel(II) and copper(II) in a solvent mixture of chloroform and acetic acid

2005 ◽  
Vol 09 (09) ◽  
pp. 646-650 ◽  
Author(s):  
Kuninobu Kasuga ◽  
Katsuyori Yashiki ◽  
Tamotsu Sugimori ◽  
Makoto Handa
Keyword(s):  
Acetic Acid ◽  
Trifluoroacetic Acid ◽  
Bathochromic Shift ◽  
Solvent Mixture ◽  
Red Shift ◽  
Weak Band ◽  
Propanol Solution ◽  
Phthalocyanine Ring

1,4,8,11,15,18,22,25-octakis(p-t-butylbenzyloxy)phthalocyanine complexes of magnesium(II), nickel(II) and copper(II) were prepared by refluxing the propanol solution of 3,6-di(p-t-butylbenzyloxy)phthalonitrile in the presence of magnesium turnings. The complexes showed intense Q-bands between 740 and 750 nm in chloroform. The magnesium(II) complex showed an additional weak band at 807 nm in chloroform, while the nickel(II) and copper(II) did not. The Q-band of the magnesium(II) species was red-shifted with increase of acetic acid in the solvent mixture of chloroform and acetic acid; 745, (765, 807) and (810, 868 nm) in chloroform, 0.1% (v/v) acetic acid and 60% (v/v) acetic acid, respectively. The magnesium(II) complex has bands at 900 and 999 nm in trifluoroacetic acid. In the solvent mixture of 1% (v/v) acetic acid, the red-shift of the Q-band was larger for the magnesium(II) derivative, a little for the nickel(II) and scarcely for the copper(II), respectively. The shift was explained by protonation of the external nitrogen atoms of the phthalocyanine ring.

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