scholarly journals Photophysical Properties and Kinetic Studies of 2-Vinylpyridine-Based Cycloplatinated(II) Complexes Containing Various Phosphine Ligands

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2034
Author(s):  
Vahideh Dolatyari ◽  
Hamid R. Shahsavari ◽  
Sepideh Habibzadeh ◽  
Reza Babadi Aghakhanpour ◽  
Sareh Paziresh ◽  
...  
Keyword(s):  
Room Temperature ◽  
Addition Reaction ◽  
Photophysical Properties ◽  
Kinetic Studies ◽  
Phosphine Ligands ◽  
The Other ◽  
Spectroscopic Methods ◽  
Yellow Orange ◽  
Oxidative Addition Reaction ◽  
Cyclometalated Ligand

A series of cycloplatinated(II) complexes with general formula of [PtMe(Vpy)(PR3)], Vpy = 2-vinylpyridine and PR3 = PPh3 (1a); PPh2Me (1b); PPhMe2 (1c), were synthesized and characterized by means of spectroscopic methods. These cycloplatinated(II) complexes were luminescent at room temperature in the yellow–orange region’s structured bands. The PPhMe2 derivative was the strongest emissive among the complexes, and the complex with PPh3 was the weakest one. Similar to many luminescent cycloplatinated(II) complexes, the emission was mainly localized on the Vpy cyclometalated ligand as the main chromophoric moiety. The present cycloplatinated(II) complexes were oxidatively reacted with MeI to yield the corresponding cycloplatinated(IV) complexes. The kinetic studies of the reaction point out to an SN2 mechanism. The complex with PPhMe2 ligand exhibited the fastest oxidative addition reaction due to the most electron-rich Pt(II) center in its structure, whereas the PPh3 derivative showed the slowest one. Interestingly, for the PPhMe2 analog, the trans isomer was stable and could be isolated as both kinetic and thermodynamic product, while the other two underwent trans to cis isomerization.

La base faible ClO4− et la chimie du ligand perchlorato. Synthèse et analyse structurale de complexes de germanium(IV): GeCl3ClO4, GeCl2(ClO4)2 et (ClO2)2Ge(ClO4)6

1989 ◽  
Vol 67 (11) ◽  
pp. 1693-1697 ◽  
Author(s):  
Mohieddine Fourati ◽  
Moncef Chaabouni ◽  
Jean Louis Pascal ◽  
Jacqueline Potier
Keyword(s):  
Vibrational Spectroscopy ◽  
Room Temperature ◽  
Complex Mixture ◽  
The Other ◽  
Colorless Liquid ◽  
Polymeric Structure ◽  
The Core ◽  
Yellow Orange ◽  
Analyse Structurale ◽  
Mode Of Coordination

Reaction of Cl2O6 with an excess of GeCl4 at room temperature yields a colorless liquid, a complex mixture. Fractional distillation leads to GeCl3ClO4 and GeCl2(ClO4)2. (ClO2)2Ge(ClO4)6, a yellow-orange solid, is obtained by reacting excess Cl2O6 with GeCl4. It sublimes into unstable crystals above 32 °C. Vibrational spectroscopy shows mainly unidentate perchlorato groups strongly bonded to Ge in the three compounds characterized. Ge is tetrahedrally surrounded in GeCl3ClO4 while it is octahedrally surrounded in the other complexes. GeCl2(ClO4)2 and (ClO2)2Ge(ClO4)6 are individual entities while GeCl2(ClO4)2 has a polymeric structure with Ge–Cl–Ge bridges. The structure of (ClO2)2Ge(ClO4)6 is analogous to that found for (ClO2)2Sn(ClO4)6. Six unidentate perchlorato groups surround the core atom; some of them interact with ClO2+, defining a new mode of coordination for ClO4 groups. Keywords: germanium, chlorine trioxide, perchlorato, syntheses, vibrational spectroscopy.

Photoreactivity (3655 Å) of various skin-photosensitizing furocoumarins with nucleic acids

1969 ◽  
Vol 24 (3) ◽  
pp. 307-314 ◽  
Author(s):  
F. Dall’Acqua ◽  
S. Marciani ◽  
G. Rodighiero
Keyword(s):  
Double Bond ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Room Temperature ◽  
Addition Reaction ◽  
The Other ◽  
Temperature Influence ◽  
Dna And Rna ◽  
Calf Thymus ◽  
Pyrimidine Bases

The photoreaction at 3655 A between skin-photosensitizing furocoumarins and DNA leads to a photo-C4-cyclo-addition reaction in which the 5 - 6 double bond of the pyrimidine bases and the 3 -4 or the 4' -5′ double bond of the furocoumarins are involved. In continuing the research in this field, the authors have investigated the photoreactions (3655 A) of psoralen, xanthotoxin (8-methoxy-psoralen), bergapten (5-methoxy-psoralen) and 8-methyl-psoralen with native calf thymus DNA. with heat-denatured DNA and with ribosomal yeast-RNA, using labelled furocoumarins and examining also the influence of the temperature at which the irradiation was made. At room temperature (22° -30°C) psoralen photoreacts in almost equally extent with each of the three nucleic acid samples, while xanthotoxin, bergapten and 8-methyl-psoralen photoreact to a greater extent with native DNA than with denatured DNA and RNA.The temperature during the irradiation (in the range examined: 2° - 30°C) does not affect the rate of the photoreactions between the four furocoumarins and native DNA, whereas it has an evident influence on the photoreactions with denatured DNA and with RNA. In the photoreaction of psoralen this influence concerns the double bond (3 - 4 or 4' -5′) of the furocoumarin which is engaged in the C4-cycloaddition to pyrimidine bases. In the case of the other furocoumarins, the rate of the photoreactions is affected: at 2° - 8°C it is greater than at 30 °C. The preliminary formation (in the dark) of a complex between the furocoumarins and the macromolecules is involved in this temperature influence.

Electron microscope studies of the plastic deformation of ternary alloys based on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 1120-1120
Author(s):  
R. Haswell ◽  
U. Bangert ◽  
P. Charsley
Keyword(s):  
Plastic Deformation ◽  
Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
The Other ◽  
Ternary Alloys ◽  
Dislocation Mobility ◽  
Semiconducting Materials ◽  
Micro Indentation

A knowledge of the behaviour of dislocations in semiconducting materials is essential to the understanding of devices which use them . This work is concerned with dislocations in alloys related to the semiconductor GaAs . Previous work on GaAs has shown that microtwinning occurs on one of the <110> rosette arms after indentation in preference to the other . We have shown that the effect of replacing some of the Ga atoms by Al results in microtwinning in both of the rosette arms.In the work to be reported dislocations in specimens of different compositions of Gax Al(1-x) As and Gax In(1-x) As have been studied by using micro indentation on a (001) face at room temperature . A range of electron microscope techniques have been used to investigate the type of dislocations and stacking faults/microtwins in the rosette arms , which are parallel to the [110] and [10] , as a function of composition for both alloys . Under certain conditions microtwinning occurs in both directions . This will be discussed in terms of the dislocation mobility.

Temperature Dependence of the Self-Assembled Styrene Based Random Ionomers in Aqueous Solution

2003 ◽  
Vol 775 ◽  
Author(s):  
Sung-Hwa Oh ◽  
Ju-Myung Song ◽  
Joon-Seop Kim ◽  
Hyang-Rim Oh ◽  
Jeong-A Yu
Keyword(s):  
Partition Coefficients ◽  
Room Temperature ◽  
Aqueous Media ◽  
The Self ◽  
Spectroscopic Methods ◽  
Ion Content ◽  
Repeat Units ◽  
Notable Effect ◽  
Order Of Magnitude ◽  
Experimental Errors

AbstractSolution behaviors of poly(styrene-co-sodium methacrylate) were studied by fluorescence spectroscopic methods using pyrene as a probe. The mol% of methacrylate was in the range 3.6–9.4. Water and N,N-dimethylforamide(DMF) mixture was used as a solvent (DMF/water = 0.2 mol %). The critical micelle (or aggregation) concentrations of ionomers and the partition coefficients of pyrene were obtained the temperature range 10–80°C. At room temperature, the values of CMCs (or CACs) were in the range 4.7 ×10-6 5.3 ×10-6 g/mL and we could not find any notable effect of the content of ionic repeat units within the experimental errors. Unlike CMCs, as the ion content increased, partitioning of pyrene between the hydrophobic aggregates and an aqueous media decreased from 1.5 ×105 to 9.4 ×104. As the temperature increased from 10 to 80 °C, the values of CMCs increased less than one order of magnitude. While, the partition coefficients of pyrene decreased one order of magnitude and the effect of the ion content became negligible.

HAYNES STELLITE ALLOY No. 98M2

Alloy Digest ◽  
1960 ◽  
Vol 9 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Physical Properties ◽  
Room Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
The Other ◽  
Stellite Alloy ◽  
Cobalt Base Alloy ◽  
Cobalt Base

Abstract HAYNES STELLITE 98M2 Alloy is a cobalt-base alloy having higher compressive strength and higher hardness than all the other cobalt-base alloys at room temperature and in the red heat range. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on heat treating, machining, and joining. Filing Code: Co-22. Producer or source: Haynes Stellite Company.

Peroxidases from Tulip Bulbs (Tulipa fosteriana, L.) Oxidize Xenobiotics NNitrosodimethylamine and N-Nitroso-N-methylaniline in vitro

1997 ◽  
Vol 62 (11) ◽  
pp. 1804-1814 ◽  
Author(s):  
Marie Stiborová ◽  
Hana Hansíková
Keyword(s):  
Cytochromes P450 ◽  
Kinetic Studies ◽  
The Other ◽  
Maximal Velocity ◽  
Michaelis Constant ◽  
Other Hand ◽  
Plant Peroxidases ◽  
Tulip Bulbs

Tulip bulbs (Tulipa fosteriana, L.) contain peroxidases catalyzing the oxidation of the xenobiotics N-nitrosodimethylamine (NDMA) and N-nitroso-N-methylaniline (NMA). Three anionic (A1, A2, A3) and four cationic (B, C, D, E) peroxidases were purified from this tissue, partially characterized and used for kinetic studies. Demethylation of NDMA and NMA producing formaldehyde is catalyzed by one anionic (A1) and three cationic (C, D, E) peroxidases. The oxidation of NDMA by tulip peroxidases exhibits the Michaelis-Menten kinetics. The apparent Michaelis constant and the maximal velocity values for this substrate were determined. On the other hand, non-Michaelian kinetics for the NMA oxidation were observed with tulip peroxidases. The most abundant cationic peroxidase (peroxidase C) was used for detailed enzymatic studies. In addition to formation of formaldehyde, methylaniline, aniline, 4-aminophenol and phenol were found to be metabolites formed from NMA. Phenol was formed presumably by N-demethylation via a benzenediazonium ion, while methylaniline, aniline and 4-aminophenol were products of denitrosation of the substrate. The efficiencies of plant peroxidases to oxidize NDMA and NMA in vitro are compared with those of cytochromes P450 and discussed.

The Reactivity of Different Active Forms of Sodium Carbonate with Respect to Sulfur Dioxide

1992 ◽  
Vol 57 (11) ◽  
pp. 2302-2308
Author(s):  
Karel Mocek ◽  
Erich Lippert ◽  
Emerich Erdös
Keyword(s):  
Thermal Decomposition ◽  
Liquid Phase ◽  
Sulfur Dioxide ◽  
Specific Surface ◽  
Surface Area ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Active Form ◽  
The Other ◽  
Kinetics Of

The kinetics of the reaction of solid sodium carbonate with sulfur dioxide depends on the microstructure of the solid, which in turn is affected by the way and conditions of its preparation. The active form, analogous to that obtained by thermal decomposition of NaHCO3, emerges from the dehydration of Na2CO3 . 10 H2O in a vacuum or its weathering in air at room temperature. The two active forms are porous and have approximately the same specific surface area. Partial hydration of the active Na2CO3 in air at room temperature followed by thermal dehydration does not bring about a significant decrease in reactivity. On the other hand, if the preparation of anhydrous Na2CO3 involves, partly or completely, the liquid phase, the reactivity of the product is substantially lower.

K2S2O8 activation by glucose at room temperature for synthesis and functionalization of heterocycles in water

2021 ◽  
Author(s):  
Joydev K. Laha ◽  
Mandeep Kaur Hunjan
Keyword(s):  
Organic Synthesis ◽  
Radical Anion ◽  
Room Temperature ◽  
Kinetic Studies ◽  
Sulfate Radical ◽  
Persulfate Activation ◽  
Sulfate Radical Anion

While persulfate activation at room temperature using glucose is primarily focused on kinetic studies of sulfate radical anion, utilization of this protocol in organic synthesis is rarely demonstrated. We reinvestigated...

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