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.

Confirmatory Tests for Aflatoxin B1

1964 ◽  
Vol 47 (5) ◽  
pp. 801-803 ◽  
Author(s):  
Peter John Andrellos ◽  
George R Reid
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Formic Acid ◽  
Thionyl Chloride ◽  
Aflatoxin B1 ◽  
Trifluoroacetic Acid ◽  
Reaction Products ◽  
Confirmatory Tests ◽  
Aflatoxin B ◽  
Layer Chromatography

Abstract Three confirmatory tests have been devised to identify aflatoxin B±. Portions of the isolated toxin are treated with formic acid-thionyl chloride, acetic acid-thionyl chloride, and trifluoroacetic acid, respectively, and aliquots of the three fluorescent reaction products are spotted on thin-layer chromatography plates. Standards treated with each of the three reagents, plus an untreated standard, are spotted on the same plate, and after development the spots are compared under ultraviolet light.

Liquid Structure of Acetic Acid−Water and Trifluoroacetic Acid−Water Mixtures Studied by Large-Angle X-ray Scattering and NMR

2007 ◽  
Vol 111 (31) ◽  
pp. 9270-9280 ◽  
Author(s):  
Toshiyuki Takamuku ◽  
Yasuhiro Kyoshoin ◽  
Hiroshi Noguchi ◽  
Shoji Kusano ◽  
Toshio Yamaguchi
Keyword(s):  
Acetic Acid ◽  
Trifluoroacetic Acid ◽  
Large Angle ◽  
Liquid Structure ◽  
Acid Water ◽  
X Ray ◽  
X Ray Scattering ◽  
Acetic Acid Water ◽  
Ray Scattering

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.

scholarly journals SYNTHESIS AND CONFORMATION OF p-(AMINO)BUTOXYCALIX[4]ARENE

2010 ◽  
Vol 7 (1) ◽  
pp. 49-57
Author(s):  
Firdaus Firdaus ◽  
Jumina Jumina ◽  
Hardjono Sastrohamidjojo
Keyword(s):  
Acetic Acid ◽  
Solvent Mixture ◽  
Reduction Reaction ◽  
Nitrogen Atmosphere ◽  
Reduction Reactions ◽  
Partial Cone ◽  
Acetic Acid Glacial

Derivatization of 5,11,17,23-tetra-t-butyl-25,26,27,28-tetrahydroxycalix[4]-arene to 5,11,17,23-tetra-amino-25,26,27,28-tetrabutoxycalix[4]arene compound via etherification, ipso nitration, and reduction reactions, respectively has been conducted. The etherification reaction was carried out by refluxed the mixture of 5,11,17,23-tetra-t-butyl-25,26,27,28-tetrahydroxy-calix[4]arene, 1-bromobutane, NaI, and NaH in solvent mixture of THF-DMF (10:1 v/v) and nitrogen atmosphere for 4 hours to resulted 5,11,17,23-tetra-t-butyl-25,26,27,28-tetrabutoxycalix[4]-arene 84% in yield; ipso nitration reaction was carried out by stirred the mixture of 5,11,17,23-tetra-t-butyl-25,26,27,28-tetrabutoxycalix[4]arene and HNO3 100% in solvent mixture of dichloromethane-acetic acid glacial (1:1 v/v) for 2 hours and than refluxed for 1 hour to resulted 5,11,17,23-tetra-nitro-25,26,27,28-tetra-butoxycalix[4]arene 50% in yield; and reduction reaction was carried out by refluxed the mixture of 5,11,17,23-tetra-nitro-25,26,27,28-tetrabutoxycalix[4]arene and SnCl2/HCl reductor in ethanol solvent for 6 hours to resulted 5,11,17,23-tetra-amino-25,26,27,28-tetrabutoxycalix[4]arene 67% in yield. In the etherification reaction, the conformation of calix[4]arene compound was converted from cone to partial cone; but in the followed reactions, i.e. nitration and reduction reactions, the conformation of calix[4]arene compounds were remain in partial cone.   Keywords: aminobutoxycalixarene, conformation, etherification, ipso nitration, reduction

Reactions of indole-3-acetic acid derivatives in trifluoroacetic acid

1995 ◽  
Vol 36 (22) ◽  
pp. 3945-3948 ◽  
Author(s):  
Jan Bergman ◽  
Eva Koch ◽  
Benjamin Pelcman
Keyword(s):  
Acetic Acid ◽  
Trifluoroacetic Acid ◽  
Indole 3 Acetic Acid

Supramolecular interactions of conjugated Zn- and protonated porphyrin polymer with carbon nanotubes

2007 ◽  
Vol 11 (03) ◽  
pp. 198-204 ◽  
Author(s):  
Fuyong Cheng ◽  
Alex Adronov
Keyword(s):  
Carbon Nanotubes ◽  
Trifluoroacetic Acid ◽  
High Speed ◽  
Bathochromic Shift ◽  
Supramolecular Interactions ◽  
Strong Interactions ◽  
Homogeneous Solutions ◽  
Repeat Units ◽  
Band Absorption ◽  
Walled Carbon Nanotubes

The interaction of a highly soluble conjugated Zn -porphyrin containing polymer with a surface of single-walled carbon nanotubes, producing a soluble polymer-nanotube complex, is reported. We found that successful complexation required the addition of trifluoroacetic acid to the solvent tetrahydrofuran in order to disrupt solvent-porphyrin coordination that prohibits close interaction of the polymer with the nanotube surface. In the presence of trifluoroacetic acid, the complex remained soluble even after excess free polymer was removed from solution, and could be centrifuged at high speed with no observable sedimentation. Furthermore, the polymer-nanotube assembly resulted in enhanced planarization and conjugation within the porphyrin polymer, which was observed via a 127 nm bathochromic shift of the Q-band absorption in the UV-vis spectrum. In addition, removal of the Zn atoms and protonation of the porphyrin repeat units under acidic conditions resulted in a polycationic polymer that also forms strong interactions with carbon nanotubes which result in soluble supramolecular complexes. Control experiments with the Zn -porphyrin monomer indicated that homogeneous solutions could be prepared by sonication, but the monomer-nanotube interactions were weak and resulted in nanotube precipitation within minutes. Atomic force microscopy and transmission electron microscopy studies indicated that the polymer is capable of exfoliating large nanotube bundles into individual tubes and small bundles that are coated in polymer.

Roles of trifluoroacetic acid, acetic acid and their salts in the synthesis of helical mesoporous materials

2009 ◽  
Vol 17 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Tao Lu ◽  
Xiangdong Yao ◽  
Max Gao Qing Lu ◽  
Yinghe He
Keyword(s):  
Acetic Acid ◽  
Mesoporous Materials ◽  
Trifluoroacetic Acid

Determination of the Iodine Value of Oils and Fats: Summary of Collaborative Study

1994 ◽  
Vol 77 (3) ◽  
pp. 674-676 ◽  
Author(s):  
David Firestone
Keyword(s):  
Acetic Acid ◽  
Iodine Value ◽  
Collaborative Study ◽  
Solvent Mixture ◽  
Acid Mixture ◽  
Collaborative Studies ◽  
Wide Range ◽  
Aoac Method ◽  
Iodine Values

Abstract Two collaborative studies were conducted using the Wijs method for determining the iodine value in a wide range of vegetable and animal oils and fats. The results obtained when using carbon tetrachlo-ride were compared to those obtained when using a substitute solvent mixture of cyclohexane and glacial acetic acid. The values reported for the iodine values indicate that the cyclohexane and acetic acid mixture can be used in place of carbon tetrachloride without loss of precision. The method has been adopted first action by AOAC INTERNATIONAL as an IUPAC/AOCS/AOAC method.

Kinetics of the addition of acids to olefins with and without boron fluoride catalysis

1967 ◽  
Vol 45 (1) ◽  
pp. 11-16 ◽  
Author(s):  
G. A. Latrèmouille ◽  
A. M. Eastham
Keyword(s):  
Activation Energy ◽  
Acetic Acid ◽  
Apparent Activation Energy ◽  
Trifluoroacetic Acid ◽  
Similar Rate ◽  
Ethylene Dichloride ◽  
Kcal Mole ◽  
Rate Law ◽  
Boron Fluoride ◽  
Kinetics Of

Isobutene reacts readily with excess trifluoroacetic acid in ethylene dichloride solution at ordinary temperatures to give t-butyl trifluoroacetate. The rate of the reaction is given, within the range of the experiments, by the expression d[ester]/dt = k[acid]2[olefin], and the apparent activation energy is about 6 kcal/mole. The rate of addition is markedly dependent on the strength of the reacting acid and is drastically reduced in the presence of mildly basic materials, such as dioxane. The boron fluoride catalyzed addition of acetic acid to 2-butene can be considered to follow a similar rate law, i.e. d[ester]/dt = k[acid·BF3]2[olefin], but only if some assumptions are made about the position of the equilibrium [Formula: see text]since only the 1:1 complex is reactive.

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