scholarly journals VII. On the relations of turacin and turacoporphyrin to the colouring matter of the blood

1896 ◽  
Vol 59 (353-358) ◽  
pp. 339-342 ◽  
Keyword(s):  
Absorption Band ◽  
Royal Society ◽  
Intense Absorption Band ◽  
Intense Absorption ◽  
Derivatives Of

In a recent paper read before the Royal Society, I have shown that the intense absorption band in the extreme violet, which is observed, by means of photography, in the spectrum of highly diluted solutions of hemoglobin and its compounds, is (with slight changes in its position) exhibited by certain of the derivatives of the blood colouring matter, e. g ., by hemochromogen and the compounds of hematin, and by that remarkably interesting coloured but iron-free derivative of the latter body, hematoporphyrin.

scholarly journals Fused bis-azacalixphyrin that reaches NIR-II absorptions

2020 ◽  
Vol 56 (6) ◽  
pp. 896-899 ◽  
Author(s):  
Lucien Lavaud ◽  
Cloé Azarias ◽  
Gabriel Canard ◽  
Simon Pascal ◽  
Joachim Galiana ◽  
...  
Keyword(s):  
Absorption Band ◽  
New Class ◽  
Intense Absorption Band ◽  
Intense Absorption

The fusion of two azacalixphyrins produces a new class of NIR-II dyes showing an intense absorption band in the 1000–1200 nm NIR range.

BF2 complexes of 1,3-diketones on the surface of phosphorus dendrimers: synthesis and study of the photoluminescence properties

2017 ◽  
Vol 95 (9) ◽  
pp. 948-953 ◽  
Author(s):  
Cédric Rouxel ◽  
Olivier Mongin ◽  
Aurélien Hameau ◽  
Armelle Ouali ◽  
Mireille Blanchard-Desce ◽  
...  
Keyword(s):  
Absorption Band ◽  
Hypsochromic Shift ◽  
Photoluminescence Properties ◽  
Intense Absorption Band ◽  
Intense Absorption

Difluoroboron complexes of monomeric and dimeric diketones and of generations 0–4 of phosphorus dendrimers ended by diketone ligands are synthesized and characterized. Their photoluminescence properties are measured. All compounds exhibit an intense absorption band in the near UV region. Both model dimers and dendrimers show a marked hypsochromic shift of this absorption band compared with the monomeric difluoroboron complex. The fluorescence of the dioxaborine complex subunit in the multichromophoric dendritic architectures is quenched compared with the emission of the isolated monomeric fluorophore, presumably due to interactions between the terminal groups of dendrimers.

scholarly journals FAR-INFRARED STUDIES OF THE STATE OF IONICAGGREGATION IN MIXTURES OF POLYETHERURETHANE AND K IONOMER STYRENE COPOLYMER WITH ACRYLIC ACID

2020 ◽  
pp. 150-160
Author(s):  
Валерий Александрович Рыжов
Keyword(s):  
Spectral Analysis ◽  
Absorption Band ◽  
Ion Pairs ◽  
Far Infrared ◽  
Carboxyl Groups ◽  
Styrene Copolymer ◽  
Ionic Groups ◽  
Intense Absorption Band ◽  
Infrared Studies ◽  
Intense Absorption

Методом спектрального анализа в дальнем (70 - 420 см) ИК-диапазоне исследовано влияние введения ионных групп на формирование сетки физических связей в композитах на основе полиэфир уретана и сополимера стирола. Анализ спектров ПУИ / Ст-со-АК (К+) композитов показал, что при увеличении содержания Ст-со-АК (К+) в системе образуется новая сетка межмолекулярных (ион-молекулярных) связей. Появление интенсивной полосы поглощения при ~ 180 см, обусловленной колебаниями катионов К+ в электростатической области анионов (СОО-) карбоксильных групп, её значительная полуширина и наличие максимумов при 145, 155, 177, 185, и 200 см свидетельствуют об образовании различных по организации форм катион-анионных ассоциатов в системе: от простых ионных пар до сложных мультиплетов и кластеров. He effect of the introduction of ionic groups on the formation of a network of physical bonds in composites based on polyether urethane (PEUI) and styrene copolymer (S-co-AA (K+)) was studied by the method of spectral analysis in the far (70-420 cm) IR range. An analysis of the spectra of PEUI / S-co-AA (K+) composites showed that with an increase in the content of S-co-AA (K+), a new network of intermolecular (ion-molecular) bonds forms in the system. The appearance of an intense absorption band at ~ 180 cm, due to vibrations of K+ cations in the electrostatic region of anions (COO-) carboxyl groups, its significant half width and the presence of maxima at 145, 155, 177, 185, and 200 cm indicate the formation of various on the organization of forms of cation-anion associates in the system: from simple ion pairs to complex multiplets and clusters.

scholarly journals The chemistry of vitamin B12. The coordination of biologically important molecules

1970 ◽  
Vol 120 (2) ◽  
pp. 263-269 ◽  
Author(s):  
H. A. O. Hill ◽  
J. M. Pratt ◽  
R. G. Thorp ◽  
B. Ward ◽  
R. J. P. Williams
Keyword(s):  
Charge Transfer ◽  
Absorption Band ◽  
Hydrogen Bonds ◽  
Vitamin B12 ◽  
Extinction Coefficient ◽  
Equilibrium Constants ◽  
Thiol Group ◽  
Intense Absorption Band ◽  
Intense Absorption ◽  
A Charge

The following equilibrium constants (given as logK in units of m−1) were determined for the substitution of co-ordinated H2O in aquocobalamin by glycine (bound through N) 5.8, cysteine (bound through S) 6.0 or 8.3, depending on the value chosen for the pK of the thiol group, and phenolate 2.9. The spectrum of the phenolate cobalamin shows an additional intense absorption band at 468nm with a molar extinction coefficient of 1.1×104, which is assigned to a charge transfer from the phenolate to the cobalt ion. Equilibrium constants have also been determined for the equilibria between adenylcobamide cyanide and CN−, HO− and H+, which show that the adenine is more easily displaced by CN− and HO− than is 5,6-dimethylbenziminazole in vitamin B12, but can be protonated by acid while still remaining co-ordinated to the cobalt. It is shown that in the binding of corrinoids to proteins and polypeptides the formation of hydrogen bonds is far more important than co-ordination by the metal.

Ultraviolet spectrum of domoic acid

1989 ◽  
Vol 67 (9) ◽  
pp. 1421-1425 ◽  
Author(s):  
Michael Falk ◽  
John A. Walter ◽  
Paul W. Wiseman
Keyword(s):  
Absorption Band ◽  
Domoic Acid ◽  
Ultraviolet Spectrum ◽  
Acid Solutions ◽  
Intense Absorption Band ◽  
Intense Absorption

The ultraviolet spectrum of aqueous domoic acid solutions has an intense absorption band, whose λmax shifts from 240.0 ± 0.3 nm at pH 1.3 to 244.7 ± 0.3 nm at pH 12.3. At the same time, its εmax increases from 24250 to 26700 L mol−1 cm−1. At pH 7 λmax is 242.8 ± 0.3 nm and εmax is 26035 ± 200 L mol−1 cm−1 Analysis of the variation of λmax and εmax with pH allowed us to estimate the values of these quantities for each of the five stages of protonation of domoic acid and to verify the pK values reported by Takemoto and Daigo. Keywords: ultraviolet spectrum, pK values, protonation, domoic acid.

scholarly journals II. Compounds isomeric with the sulphocyanic ethers.—I. On the mustard oil of the ethyl series

1868 ◽  
Vol 16 ◽  
pp. 254-258
Keyword(s):  
Royal Society ◽  
The Other ◽  
Mustard Oil ◽  
Other Hand ◽  
Derivatives Of

The results of my researches on the chloroform-derivatives of the primary monamines, which, as I have shown, are isomeric with the nitriles, could not fail to direct my attention to allied groups of bodies, with the view of discovering similar isomerisms. In a note communicated to the Royal Society some months ago, I expressed the expectations which even then appeared to be justified in the following manner:—“In conclusion, I may be permitted to announce as everv probable the existence of a series of bodies isomeric with the sulphocyanides. Already M. Cloëz has shown that the action of chloride of cyanogen on ethylate of potassium gives rise to the formation of an ethylic cyanate possessing properties absolutely different from those belonging to the cyanate discovered by M. Wurtz. On comparing, on the other hand the properties of the methylic and ethylic sulphocyamdes with those of the sulphocyanides of allyl and phenyl, it can scarcely be doubted that we have here the representatives of two groups entirely different, and that the terms of the methyl- and ethyl-series which correspond to oil of mustard, and to the sulphocyanide of phenyl, still remain to be discovered. Experiments with which I am now engaged will show whether these bodies cannot be obtained by the action of the iodides of methyl and ethyl on sulphocyanide of silver."

.VII. Contributions towards the history of the colouring matters derived from aniline

1863 ◽  
Vol 12 ◽  
pp. 645-647 ◽  
Keyword(s):  
Royal Society ◽  
Short Paper ◽  
Aromatic Diamines ◽  
History Of ◽  
Derivatives Of ◽  
Careful Comparison ◽  
Phenylene Diamine

In a short paper recently submitted to the Royal Society, I pointed out the existence of two aromatic diamines, both represented by the formula C 6 H 8 N 2 = (C 6 H 4 )'' H 2 H 2 } N 2 , and closely resembling each other, but differing in some of their fundamental characters to such an extent that I did not hesitate to assert their individuality, and to distinguish them as alpha-pheny-lene-diamine and beta-phenylene-diamine. The existence of two closely allied bodies among the diatomic derivatives of the phenyl-series very naturally suggested the idea of searching for two similarly related monatomic bases of the same group, and accordingly I undertook during the last week a careful comparison of specimens of aniline prepared by different piocesses. This com parative study is still incomplete, but I beg leave to record even now an observation which appears to merit the attention of chemists.

scholarly journals A comparison of the spectra of fluorescent Röntgen radiations

1913 ◽  
Vol 88 (600) ◽  
pp. 24-37 ◽  
Keyword(s):  
Absorption Band ◽  
Absorption Coefficient ◽  
Scattered Radiation ◽  
Royal Society ◽  
Radiation Characteristic ◽  
Primary Beam ◽  
Selective Absorption ◽  
Radioactive Elements ◽  
Gold Platinum

In a previous paper published in the 'Proceedings of the Royal Society,' it has been shown that there is a second group of elements consisting of tungsten, gold platinum, bismuth, and the radioactive elements uranium and thorium, which emit secondary fluorescent X-radiation when excited by a suitable primary beam of Röntgen rays. The properties which the radiations of this group (Group L) have been shown to possess in common with the radiations of Group K (elements Cr-I), investigated some year ago by Prof. Barkla, are as follows:—(1) The radiations emitted by any particular element when excited consist of two distinct types: ( a ) the scattered radiation, having the same penetrating power as the primary beam and indistinguishable from it; ( b ) the homogeneous X-radiation characteristic of the particular element in question. (2) Each element exerts a selective absorption for radiations which are of such a degree of hardness that they lie in the neighbourhood of an "absorption band." In the case of the elements of Group L, to demonstrate the homogeneity of the radiations, allowance had to be made for the scattered radiation which always accompanies the homogeneous constituent, but which in the case of the heavier elements is present in such magnitude as to mask, if no correction is applied, the true homogeneity. In the experiment described in the paper referred to, the absorption in aluminium of the various radiations has been measured. In Tables I and II the absorption coefficient ( λ / ρ ) is defined by the equation I = I 0 e - λx , where ρ is the density of aluminium.

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