The valence tautomer of methyl-7-oxa-bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate and its dimer

1967 ◽  
Vol 45 (19) ◽  
pp. 2235-2242 ◽  
Author(s):  
P. Deslongchamps ◽  
J. Kallos
Keyword(s):  
Spectral Properties ◽  
Compound Ii ◽  
Valence Tautomer

Irradiation of diester I gave the photoisomer II. This quadricyclic compound (II) dimerized on standing. A structure for the dimer is proposed on the basis of its spectral properties.

scholarly journals Tautomerism in Fuscin - A DFT Treatment

2020 ◽  
pp. 243-259
Author(s):  
Lemi Türker
Keyword(s):  
Density Functional Theory ◽  
Natural Product ◽  
Quantum Chemical ◽  
Spectral Properties ◽  
Density Functional ◽  
Functional Theory ◽  
Valence Tautomerism ◽  
Valence Tautomer ◽  
Benzenoid Ring ◽  
Stable Structures

Fuscin, a natural product having various functionalities, may exhibit 1,3- and 1,5-proton tautomerism, as well as valence tautomerism via its 1,5-proton tautomer. All those possible forms are investigated within the realm of density functional theory with the constraints of B3LYP/6-311+G(d,p) level. NICS(0) calculation has been performed for the valence tautomer which possesses a benzenoid ring. The tautomers are found to be stable structures but the valence tautomer is the least likely one. Some QSAR, quantum chemical and spectral properties are obtained and discussed.

scholarly journals The formation of pyridine haemochromogen

1965 ◽  
Vol 97 (1) ◽  
pp. 187-193 ◽  
Author(s):  
WA Gallagher ◽  
WB Elliott
Keyword(s):  
Ionic Strength ◽  
Aqueous Medium ◽  
Spectral Properties ◽  
Graphical Analysis ◽  
Alkaline Media ◽  
Compound I ◽  
Low Concentrations ◽  
Compound Ii ◽  
Low Ionic Strength ◽  
Hydrophobic Bonding

1. Titration of haem with pyridine in alkaline media of low ionic strength yields a true pyridine haemochromogen, compound III, at very low concentrations of pyridine. 2. Graphical analysis of this titration gives the first spectrophotometric evidence for a dimeric haem. 3. Compound III is unstable and tends to aggregate to a second compound, compound II, whose formation is enhanced under those conditions favourable to hydrophobic bonding. 4. At higher concentrations of pyridine, compound II is dispersed to yield the classical pyridine haemochromogen, compound I, whose spectral properties are essentially those of pyridine haemochromogen in a non-aqueous medium.

Model of multicomponent narrow-band periodical non-stationary random signal

2020 ◽  
Vol 2020 (48) ◽  
pp. 17-24
Author(s):  
I.M. Javorskyj ◽  
◽  
R.M. Yuzefovych ◽  
P.R. Kurapov ◽  
◽  
...  
Keyword(s):  
Time Series ◽  
Real Time ◽  
Hilbert Transform ◽  
Spectral Properties ◽  
Narrow Band ◽  
Analytic Signal ◽  
Random Signal ◽  
Hilbert Transformation ◽  
The Hilbert Transform

The correlation and spectral properties of a multicomponent narrowband periodical non-stationary random signal (PNRS) and its Hilbert transformation are considered. It is shown that multicomponent narrowband PNRS differ from the monocomponent signal. This difference is caused by correlation of the quadratures for the different carrier harmonics. Such features of the analytic signal must be taken into account when we use the Hilbert transform for the analysis of real time series.

Structure and Spectral Properties of New Composites Based on Metal Alkanoates with Gold Nanoparticles

2015 ◽  
Vol 60 (04) ◽  
pp. 356-361 ◽  
Author(s):  
A. Tolochko ◽  
◽  
P. Teselko ◽  
A. Lyashchova ◽  
D. Fedorenko ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Spectral Properties

New Amine and Aromatic Substituted Analogues of Phencyclidine: Synthesis and Determination of Acute and Chronic Pain Activities

2019 ◽  
Vol 22 (8) ◽  
pp. 570-576
Author(s):  
Maryam Shokrollahi ◽  
Marjaneh Samadizadeh ◽  
Mohsen Khalili ◽  
Seyed A. Sobhanian ◽  
Abbas Ahmadi
Keyword(s):  
Nmda Receptors ◽  
Phenyl Ring ◽  
Piperidine Ring ◽  
Methyl Group ◽  
Physiological Properties ◽  
Antinociceptive Effects ◽  
The Central Nervous System ◽  
Analgesic Activities ◽  
Compound Ii ◽  
New Compounds

Background: Phencyclidine (PCP, I) is a synthetic drug with remarkable physiological properties. PCP and its analogues exert many pharmacological activities and interact with some neurotransmitter systems in the central nervous system like particular affinity for PCP sites in NMDA receptors or dopamine uptake blocking or even both. Aim and Objective: The following research, methyl group with electron-donating and dipole moment characters was added in different positions of phenyl ring along with the substitution of benzylamine (with many pharmacological effects) instead of piperidine ring of I to produce new compounds (II-V) of this family with more analgesic activities. Materials and Methods: Analgesic activities of these new compounds were measured by tail immersion and formalin tests for acute and chronic pains, respectively. Also, the outcomes were compared with control and PCP (10 mg/kg) groups. Results: The results indicate that compounds III, IV, and V have more acute and chronic antinociceptive effects than PCP and compound II which may be concerned with more antagonizing activities of these new painkillers for the blockage of dopamine reuptake as well as high affinity for NMDA receptors PCP binding site. Conclusion: It can be concluded that the benzylamine derivative of phencyclidine with a methyl group on the benzyl position on phenyl ring (V) is a more appropriate candidate to reduce acute and chronic (thermal and chemical) pains compared to other substituted phenyl analogs (II-IV) and PCP.

Cline’s formula for g-Drazin inverses in a ring

Filomat ◽  
2019 ◽  
Vol 33 (8) ◽  
pp. 2249-2255
Author(s):  
Huanyin Chen ◽  
Marjan Abdolyousefi
Keyword(s):  
Operator Theory ◽  
Spectral Properties ◽  
Associative Ring ◽  
Linear Operators ◽  
Drazin Inverse ◽  
Bounded Linear Operators ◽  
Bounded Linear ◽  
Cline’S Formula

It is well known that for an associative ring R, if ab has g-Drazin inverse then ba has g-Drazin inverse. In this case, (ba)d = b((ab)d)2a. This formula is so-called Cline?s formula for g-Drazin inverse, which plays an elementary role in matrix and operator theory. In this paper, we generalize Cline?s formula to the wider case. In particular, as applications, we obtain new common spectral properties of bounded linear operators.

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